Serotonin receptor subtype with anxiolytic effects, particularly in amygdala and hippocampus, and the primary target mediating SSRI therapeutic benefit. As an autoreceptor on serotonin neurons, it temporarily reduces serotonin release until desensitization occurs; buspirone acts directly on this receptor.

Serotonin receptor subtype whose activation produces anxiety-increasing effects in amygdala and BNST. Early SSRI-induced activation of 5-HT2C receptors (before 5-HT1A desensitization) causes initial treatment worsening; over weeks, these receptors desensitize, allowing anti-anxiety effects to emerge.

Serotonin-transporter-linked polymorphic region. A genetic variant in the SERT gene promoter once thought to predict depression and anxiety risk. The short allele was widely studied but large replication efforts (including Culverhouse et al., 2018) found no reliable main effect. Now considered a cautionary tale in psychiatric genetics.

A plan under Section 504 of the Rehabilitation Act providing accommodations (but not specialized instruction) for students with disabilities.

American Academy of Child and Adolescent Psychiatry. Publishes practice parameters for assessment and treatment of childhood psychiatric disorders.

American Academy of Pediatrics. Publishes clinical practice guidelines for psychiatric and developmental disorders in children.

Adolescent Brain Cognitive Development Study. An ongoing longitudinal cohort of roughly 12,000 U.S. youth, providing the most granular developmental neuroimaging data available for studying how the brain develops through adolescence.

Brief staring spells caused by abnormal brain electrical activity. Can mimic inattention.

A change in how instruction or testing is delivered that removes barriers without altering content or expectations. Contrast with modification, which changes what the student is expected to learn.

Adverse Childhood Experience. An index of childhood trauma exposure linked to increased risk of psychiatric and medical conditions.

Acceptance and Commitment Therapy; transdiagnostic psychotherapy emphasizing values clarification, acceptance of unwanted internal experiences (thoughts, sensations, emotions), and committed action toward meaningful life goals. Shows efficacy across anxiety disorders as an alternative to trauma-focused or disorder-specific CBT.

Americans with Disabilities Act. Federal civil rights law prohibiting discrimination against individuals with disabilities.

Brand name for mixed amphetamine salts (immediate-release). A first-line stimulant for ADHD combining four amphetamine salts.

Extended-release formulation of mixed amphetamine salts using a beaded delivery system. Duration approximately 10-12 hours.

ADHD Rating Scale. A standardized symptom severity measure based on DSM criteria, used in clinical trials and practice.

The degree to which a patient follows prescribed treatment recommendations.

Autism Diagnostic Interview-Revised. A structured caregiver interview for autism diagnosis.

Autism Diagnostic Observation Schedule, 2nd Edition. A standardized assessment tool for diagnosing autism spectrum disorder.

A substance that binds to a receptor and activates it, mimicking the natural signaling molecule.

An intensely distressing sense of inner restlessness and inability to sit still. A potential side effect of some psychiatric medications.

A medication that activates alpha-2 adrenergic receptors, reducing sympathetic nervous system activity.

Tertiary amine tricyclic antidepressant with broad receptor activity (serotonin, norepinephrine, histamine, acetylcholine). Used primarily for chronic pain and migraine prophylaxis rather than anxiety due to its side effect burden and overdose lethality compared to SSRIs.

A stimulant medication that enhances dopamine and norepinephrine signaling through reuptake inhibition plus forced release. Includes mixed amphetamine salts (Adderall) and lisdexamfetamine (Vyvanse).

A brain structure involved in processing fear, emotional memory, and threat detection. Also plays a role in reward processing and social cognition.

The inability to experience pleasure from activities that are normally enjoyable.

A substance that binds to a receptor and blocks its activation.

Changing environmental triggers before a behavior occurs to prevent problem behaviors.

A brain region involved in error detection, conflict monitoring, and emotional regulation.

A brain network relationship where one network's activation reliably coincides with another network's deactivation. The default mode network and task-positive network are anti-correlated: when one turns on, the other turns off. In ADHD, this switching is unreliable.

A state of excessive worry, apprehension, or fear that is disproportionate to the situation. When persistent and impairing, it constitutes an anxiety disorder. Anxiety is among the most common psychiatric comorbidities in ADHD.

Extended-release methylphenidate using a multi-particulate beaded system with a 40:60 immediate-to-delayed release ratio.

An atypical antipsychotic with dopamine partial agonist activity, used as adjunctive treatment for depression and irritability across diagnostic categories.

Autism Spectrum Disorder. A neurodevelopmental disorder characterized by differences in social communication and restricted/repetitive behaviors.

The co-occurrence of Autism Spectrum Disorder with another condition such as ADHD. The DSM-5 removed the previous prohibition on dual ASD-ADHD diagnosis, recognizing that 30-50% of individuals with ASD independently meet criteria for ADHD with distinct impairment from each disorder.

Adult ADHD Self-Report Scale. A brief screening tool for ADHD symptoms in adults.

Any device or software that helps a person with a disability perform tasks they would otherwise find difficult.

A selective norepinephrine reuptake inhibitor (NRI) used for attention-deficit disorders. Brand name: Strattera. Takes 6–8 weeks for full therapeutic effect, unlike the immediate action of stimulants.

Adding a second medication or intervention to an existing treatment to enhance the overall response.

A neurodevelopmental condition characterized by differences in social communication and restricted or repetitive behaviors. Frequently co-occurs with ADHD; DSM-5 permits dual diagnosis. Abbreviated ASD.

Combination of serdexmethylphenidate (a prodrug) and dexmethylphenidate. Designed to provide both immediate and extended coverage.

A group of subcortical nuclei (including the caudate, putamen, and globus pallidus) involved in motor control, habit formation, and reward processing. Structural and functional differences in basal ganglia circuits are consistently observed in ADHD neuroimaging research.

The prevalence of a condition in the population being tested, which directly affects the meaning of test results.

Brain-Derived Neurotrophic Factor. A protein essential for the growth and survival of neurons, involved in neuroplasticity and learning.

A therapeutic technique that systematically increases engagement in meaningful activities to counteract patterns of avoidance and withdrawal.

The brain's ability to suppress an automatic response and pause before acting, allowing deliberate decision-making. A foundational concept in Barkley's model of ADHD, where deficient behavioral inhibition is considered the core deficit.

An evidence-based psychosocial intervention that teaches parents specific behavior management techniques including positive reinforcement, structured routines, and consistent consequences. Recommended as first-line treatment for preschoolers with ADHD.

A class of medications that enhance GABA activity to produce sedative, anxiolytic, and muscle-relaxant effects. Generally avoided in ADHD populations due to cognitive dulling, dependence risk, and potential for misuse.

The proportion of an administered drug that reaches the bloodstream in active form.

Behavior Intervention Plan. A plan based on an FBA that outlines strategies for addressing problem behaviors in school settings.

The FDA's strongest safety warning on a medication label (formally called a Boxed Warning), indicating serious or life-threatening risks.

Body Mass Index. A measure of body weight relative to height, widely used in clinical assessment and growth monitoring.

Behavioral Parent Training. An evidence-based intervention teaching parents specific behavioral management strategies for children with behavioral disorders.

Behavior Rating Inventory of Executive Function, 2nd Edition. A rating scale measuring executive function abilities in daily life.

A rating scale that screens across many types of problems rather than focusing on one disorder.

An antidepressant (Wellbutrin) sometimes used off-label for attention and mood disorders. A norepinephrine-dopamine reuptake inhibitor (NDRI).

Canadian ADHD Resource Alliance. Publishes Canadian guidelines and medication charts for ADHD treatment.

Adenosine receptor antagonist and the most widely consumed psychoactive substance. In anxiety contexts, caffeine can provoke or exacerbate panic attacks and generalized anxiety symptoms through sympathetic activation; doses above 200-300 mg/day are clinically relevant.

An anticonvulsant (Tegretol) used for bipolar disorder and seizures. Strong CYP3A4 inducer affecting metabolism of many other medications.

A class of neurotransmitters that includes dopamine and norepinephrine (and epinephrine). Synthesized from the amino acid tyrosine. These chemicals are essential for prefrontal cortex function and are the primary targets of ADHD medications. PFC performance follows an inverted-U curve for catecholamine levels.

The chemical family of neurotransmitters that includes dopamine and norepinephrine. Central to understanding conditions involving attention, motivation, and executive function.

A deep brain structure involved in regulating motor activity and cognitive control.

Child Behavior Checklist. A broadband rating scale screening for emotional and behavioral problems in children and adolescents.

Cognitive Behavioral Therapy. An evidence-based psychotherapy approach that targets maladaptive thought patterns and behaviors.

Cognitive Disengagement Syndrome. A neurodevelopmental presentation characterized by mental fogginess, slow processing speed, and reduced arousal. Formerly called Sluggish Cognitive Tempo (SCT). Statistically separable from ADHD-Inattentive but frequently co-occurring.

The point at which increasing the dose or intensity of a measure no longer produces additional effect.

A brain region traditionally associated with motor coordination, now known to contribute to cognitive timing and error correction.

Center for Epidemiologic Studies Depression Scale. A screening tool for depressive symptoms.

Carboxylesterase 1. The liver enzyme primarily responsible for metabolizing methylphenidate. Genetic variants affect drug levels.

Children's Global Assessment Scale. A clinician-rated measure of overall functioning in children.

Clinical Global Impressions-Severity scale. A clinician-rated measure of overall symptom burden, scored from 1 (not ill) to 7 (extremely ill).

The legal obligation under IDEA for schools to identify, locate, and evaluate all children with suspected disabilities.

A healthcare framework for managing long-term conditions through ongoing monitoring and collaborative care.

Confidence Interval. A statistical range expressing the precision of an estimate, typically at 95% confidence.

Relating to biological rhythms that follow an approximately 24-hour cycle, most notably the sleep-wake cycle. Circadian disruption is common in ADHD and can worsen inattention and emotional dysregulation.

A biological shift toward later sleep-wake timing.

An SSRI antidepressant (Celexa) used for depression and anxiety. Has a dose-dependent risk of QTc prolongation, which strictly limits maximum doses, especially in older adults.

A pharmacokinetic measure of how efficiently the body removes a drug from the bloodstream.

Whether a statistical finding is large enough to matter in real-world patient care.

An improvement large enough to make a noticeable difference in a patient's daily functioning.

A non-selective alpha-2 adrenergic agonist used for attention disorders, particularly for hyperarousal, sleep difficulties, and as an adjunct to stimulants. Extended-release brand name: Kapvay.

Central nervous system; the brain and spinal cord. CNS-active medications cross the blood-brain barrier and affect neural function.

A systematic review published by the Cochrane Collaboration, considered among the highest quality evidence summaries.

A necessary helper molecule that an enzyme requires to function. Iron is a cofactor for tyrosine hydroxylase, the enzyme that produces dopamine. Iron deficiency can impair dopamine synthesis and worsen ADHD symptoms.

A structured psychotherapy that targets maladaptive thought patterns and behaviors through skills training, cognitive restructuring, and behavioral activation. Used in ADHD primarily for comorbid anxiety, depression, and as an adjunct for organizational skills.

A neurodevelopmental presentation characterized by mental fogginess, slow processing speed, daydreaminess, and reduced arousal. Statistically separable from ADHD-Inattentive but frequently co-occurring. Formerly called Sluggish Cognitive Tempo (SCT). Not yet a formal DSM diagnosis.

A CBT technique that identifies and challenges distorted thinking patterns.

A measure of effect size expressing the difference between two group means in standard deviation units.

Occurring alongside another condition in the same individual. ADHD has high comorbidity rates: roughly two-thirds of children with ADHD meet criteria for at least one additional psychiatric diagnosis.

The co-occurrence of two or more diagnoses in the same patient. In psychiatry, comorbidity is common and significantly affects treatment planning.

Extended-release methylphenidate using the OROS (osmotic-release oral system) push-pull technology. Duration 10-12 hours with an ascending release profile.

A behavioral disorder characterized by persistent violation of societal norms and the rights of others.

A range of values within which the true population parameter is likely to fall, typically at 95% confidence.

A family of standardized ADHD rating scales (Conners 3, Conners 4) that use parent, teacher, and self-report forms to quantify symptom severity across inattention, hyperactivity-impulsivity, and associated domains.

A behavioral approach using structured rewards and consequences to shape behavior.

A vision disorder that makes near-work painful and is often mistaken for inattention.

Continuous Performance Test. A computerized test measuring sustained attention and impulse control.

A screening tool for substance use risk in adolescents, useful in comprehensive psychiatric assessment.

Corticotropin-releasing hormone; neuropeptide released by hypothalamus that initiates the HPA axis stress cascade by stimulating pituitary ACTH release, which triggers adrenal cortisol secretion. In anxiety disorders, chronic CRH elevation drives persistent HPA axis activation; CRF1 receptor antagonists were developed to block this but failed clinically.

The normal discrepancy between different raters (e.g., parent vs. teacher) when reporting on the same patient.

A clinical trial design in which each participant receives both the experimental and control treatments in sequence, serving as their own control. Reduces between-subject variability but requires a washout period between conditions.

Cytochrome P450 1A2. A liver enzyme metabolizing caffeine and some antipsychotics (notably olanzapine and clozapine). Activity is significantly increased by tobacco smoking, which can lower medication levels.

Cytochrome P450 2D6. A liver enzyme involved in metabolizing many psychotropic medications. Genetic variants and drug interactions affect medication levels.

Cytochrome P450 3A4. The most abundant liver enzyme, responsible for metabolizing many psychiatric medications.

A family of liver enzymes (designated CYP followed by numbers and letters, such as CYP2D6 or CYP3A4) responsible for metabolizing most psychiatric medications. Genetic variation in cytochrome enzymes is a major source of individual differences in drug response.

Dopamine Transporter. The protein on presynaptic neurons that recycles dopamine from the synapse. Primary target of stimulant medications.

Methylphenidate transdermal patch. Bypasses first-pass metabolism, allowing lower effective doses. Applied to the hip for 9 hours.

Daily Behavior Report Card. A school-based monitoring tool linking classroom behavior to home consequences.

Dialectical Behavior Therapy. A therapy combining cognitive-behavioral techniques with mindfulness, particularly useful for emotional dysregulation.

Developmental Coordination Disorder. A motor skills condition causing clumsiness and difficulty with fine and gross motor tasks.

A brain network active during mind-wandering and self-referential thought. Shows abnormal connectivity in several psychiatric conditions.

A mood disorder characterized by persistent low mood, loss of interest or pleasure, and associated cognitive and physical symptoms. Major depressive disorder is a common comorbidity in ADHD, particularly in adolescents and adults.

A tricyclic antidepressant sometimes used off-label for attention and mood disorders, and neuropathic pain. Works via norepinephrine reuptake inhibition.

Deficient Emotional Self-Regulation. A framework describing emotional dysregulation as a core feature of certain conditions.

The expected pattern of skill acquisition and behavioral change across childhood and adolescence.

Brand name for dextroamphetamine, the d-isomer of amphetamine. Available in immediate-release and spansule (extended-release) forms.

The active (d-) enantiomer of methylphenidate. Achieves the same clinical effect at half the milligram dose. Brand names: Focalin, Focalin XR.

The d-enantiomer of amphetamine, highly potent at dopaminergic synapses. Brand name: Dexedrine.

When a prominent diagnosis causes clinicians to attribute new symptoms to the existing condition rather than considering additional diagnoses.

The degree to which a diagnosis remains consistent over time across repeated assessments.

The systematic process of distinguishing between conditions that share similar symptoms.

The time at which endogenous melatonin levels begin rising under dim lighting conditions. A reliable biomarker of circadian phase used clinically to guide the timing of melatonin supplementation. Abbreviated DLMO.

First-generation antihistamine (Benadryl) with anticholinergic properties sometimes used as a sleep aid. Not recommended for anxiety due to cognitive impairment, tolerance, anticholinergic burden, and association with increased dementia risk with long-term use in older adults.

Physical and psychological symptoms arising from abrupt cessation or rapid tapering of psychotropic medications (particularly SNRIs), including dizziness, electric shock-like sensations, nausea, insomnia, and dysphoria. More severe with drugs having shorter half-lives and higher potency; managed by slow tapering schedules.

A structured period off medication to assess whether ongoing treatment is still necessary.

A childhood condition characterized by severe, recurrent temper outbursts and persistent irritable or angry mood between outbursts. Introduced in DSM-5 to address concerns about overdiagnosis of pediatric bipolar disorder. Abbreviated DMDD.

A disconnection from one's thoughts, feelings, surroundings, or identity, often associated with trauma.

Dim light melatonin onset. The time at which endogenous melatonin levels begin rising under dim lighting conditions. Used as a reliable biomarker for circadian phase and to guide the timing of exogenous melatonin administration.

Disruptive mood dysregulation disorder. A childhood condition characterized by severe, recurrent temper outbursts and persistent irritable or angry mood between outbursts. Introduced in DSM-5 to address concerns about overdiagnosis of pediatric bipolar disorder.

An epigenetic mechanism where methyl groups attach to DNA, typically silencing gene expression without changing the DNA sequence. Environmental exposures (stress, toxins, nutrition) can alter methylation patterns, providing a molecular pathway by which experience shapes gene expression across the lifespan.

A neurotransmitter central to reward, motivation, and executive function. Key pathways: mesocortical (ventral tegmental area → prefrontal cortex, involved in attention and working memory), mesolimbic (VTA → nucleus accumbens, involved in reward and motivation), and nigrostriatal (substantia nigra → striatum, involved in motor control). The primary target of stimulant medications in ADHD.

The region of the prefrontal cortex most associated with working memory and cognitive control.

The relationship between a medication dose and the magnitude of its therapeutic or adverse effects.

A study design where neither participants nor researchers know which intervention each participant is receiving.

A planned period off medication, used to reassess ongoing need, evaluate side effects, or allow physiological recovery.

When one medication affects the metabolism, absorption, or action of another medication.

Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (2022). The standard classification system for psychiatric diagnoses in the United States.

Diffusion Tensor Imaging. A neuroimaging technique that maps white matter pathways in the brain.

A formal legal proceeding to resolve disputes between families and schools about special education services.

An SNRI antidepressant (Cymbalta) used for depression, anxiety, and chronic pain conditions. Also approved for stress urinary incontinence.

Dual-energy X-ray Absorptiometry. A scan measuring bone density, sometimes relevant for monitoring growth during medication treatment.

A clinical term for Specific Learning Disorder with impairment in mathematics, affecting number sense, calculation, and mathematical reasoning.

A clinical term for difficulties with written expression, particularly affecting handwriting, spelling, and the mechanics of getting thoughts onto paper.

A state of pronounced unease, irritability, or emotional discomfort.

A group of conditions characterized by persistent disturbances in eating behavior and related distress.

Electrocardiogram. A test recording the heart's electrical activity, sometimes recommended before starting medications that may affect cardiac rhythm.

Electroencephalogram. A test that records electrical activity in the brain.

A statistical measure of the magnitude of a difference between groups or a relationship between variables.

Eye Movement Desensitization and Reprocessing; psychotherapy protocol for post-traumatic stress and trauma-related anxiety disorders involving bilateral stimulation (eye movements, tapping, or tones) paired with trauma processing. Mechanism remains debated; efficacy for PTSD is established though equivalent to prolonged exposure.

Difficulty managing emotional responses: quick to anger, easily frustrated, intense reactions.

Mirror-image forms of the same molecule with different pharmacological activity.

Chemical modifications that change gene expression without altering the DNA sequence itself. Environmental exposures like stress or toxins can create epigenetic changes that affect brain development and may contribute to ADHD risk.

Exposure and Response Prevention. The first-line behavioral therapy for OCD, involving gradual confrontation with feared stimuli.

An SSRI antidepressant (Lexapro) widely used for anxiety disorders and depression. Better tolerated than some earlier SSRIs with minimal drug interactions.

A set of cognitive processes including working memory, flexible thinking, and self-control.

A testing accommodation providing additional time to complete assessments.

A medication formulation designed to release its active ingredient gradually over an extended period, typically 8 to 16 hours. Reduces dosing frequency and provides smoother symptom coverage throughout the day.

Outwardly directed behavioral problems including aggression, defiance, and hyperactivity.

The gradual disappearance of a learned behavior when its reinforcement is removed. Typically preceded by an 'extinction burst' where the behavior temporarily intensifies before improving.

Neurobiological process by which the brain learns that a previously feared stimulus is now safe, mediated by ventromedial prefrontal cortex (vmPFC) building a competing safety memory. Forms the core neural mechanism underlying exposure therapy.

Free Appropriate Public Education. The legal standard under IDEA requiring schools to provide education tailored to students with disabilities at no cost.

Functional Behavioral Assessment. A systematic process for identifying the function of problem behaviors, used to develop intervention plans.

U.S. Food and Drug Administration. The federal agency responsible for approving medications and medical devices.

A regulatory pathway (510(k)) in which the FDA determines a medical device is substantially equivalent to an existing approved device. FDA clearance is a lower bar than FDA approval and does not require clinical trials demonstrating efficacy. Important distinction when evaluating marketed ADHD diagnostic devices.

Primary evidence-based treatment choice for an anxiety disorder, recommended as the initial intervention based on clinical trial data and treatment guidelines. SSRIs/SNRIs and CBT are first-line for most anxiety disorders; benzodiazepines are not.

The initial processing of an oral drug by the liver before it reaches systemic circulation. Some drugs lose a substantial fraction of their dose during this process, reducing bioavailability.

An SSRI antidepressant (Prozac). Widely used for depression, anxiety, and OCD. A strong CYP2D6 inhibitor relevant to many medication interactions.

An SSRI used primarily for OCD and anxiety disorders. Notable as a strong CYP1A2 and CYP2C19 inhibitor affecting multiple drug metabolic pathways.

Functional Magnetic Resonance Imaging. A neuroimaging technique that measures brain activity by detecting blood flow changes.

Brand name for dexmethylphenidate, the pharmacologically active d-isomer of methylphenidate.

Extended-release dexmethylphenidate using a beaded delivery system.

A neuroimaging measurement from diffusion tensor imaging (DTI) that indicates how organized white matter tracts are. Higher values indicate more organized, intact connections; lower values suggest degraded wiring.

A systematic process for identifying the triggers and consequences maintaining a problem behavior.

The real-world impact of symptoms on daily life, including school, work, relationships, and self-care.

Gamma-aminobutyric acid. The brain's primary inhibitory neurotransmitter. Reduces neuronal excitability throughout the nervous system. Relevant to ADHD through its role in impulse control circuits and as the target of some medications used for comorbid conditions (anxiety, insomnia).

Generalized Anxiety Disorder. A condition characterized by persistent, excessive worry across multiple life domains.

Global Assessment of Functioning. A clinician-rated scale of overall psychological, social, and occupational functioning (0-100 scale).

The transfer of skills learned in one setting (e.g., therapy) to other real-world environments.

An anxiety disorder characterized by persistent, excessive worry across multiple life domains.

When an apparent environmental risk factor for a condition actually reflects shared genetic influences. For example, prenatal smoking correlates with ADHD, but this may reflect inherited traits (impulsivity, risk-taking) that both increase smoking likelihood and ADHD risk, rather than a direct causal effect of smoking on the developing brain.

The brain's primary excitatory neurotransmitter. Involved in learning, memory, and synaptic plasticity. Emerging research suggests glutamatergic dysfunction may contribute to ADHD pathophysiology, particularly in cortico-striatal circuits.

The rate of height or weight gain over time, used to monitor potential medication effects on development.

A selective alpha-2A adrenergic agonist used for attention and impulse control disorders, particularly helpful for emotional dysregulation and tics. Extended-release brand name: Intuniv.

Genome-Wide Association Study. A research method scanning entire genomes to find genetic variants associated with a trait or disorder.

Gene-Environment Interaction. The concept that genetic predisposition and environmental factors jointly influence disease expression.

The time it takes for the body to clear half the drug from the bloodstream. Influences how long a medication remains active, though clinical effects of some drugs can outlast their blood levels.

A measure of how much a factor increases or decreases risk over time.

Healthcare Effectiveness Data and Information Set. A set of quality measures used to evaluate healthcare performance.

Liver damage caused by medications or other substances.

The proportion of variation in a trait that is attributable to genetic differences within a population.

In meta-analysis, the degree of variability in study results beyond what would be expected by chance.

A brain structure essential for memory formation and spatial navigation.

Hierarchical Taxonomy of Psychopathology. A dimensional diagnostic framework that organizes mental health conditions along continuous spectra rather than discrete categories, which may better capture the reality of conditions like ADHD.

Hypothalamic-Pituitary-Adrenal axis. The body's central stress response system.

A state of heightened alertness and scanning for threats.

Abnormally low blood sodium concentration (below 135 mEq/L). An uncommon but potentially dangerous adverse effect of SSRIs and SNRIs, particularly in elderly patients. Presents with confusion, nausea, headache, and in severe cases seizures.

International Classification of Diseases, 11th Revision (2022). The WHO's global diagnostic classification system used in most countries.

Individuals with Disabilities Education Act. Federal law requiring schools to provide free appropriate public education (FAPE) to eligible students with disabilities.

Individualized Education Program. A legally binding document under IDEA that provides specialized instruction and services for students with disabilities.

A tricyclic antidepressant used for depression, anxiety, and nocturnal enuresis. An older medication that has fallen out of favor due to more modern alternatives.

A medication formulation that releases its full dose shortly after ingestion, typically providing 3 to 6 hours of effect. Offers dosing flexibility but requires multiple daily doses for sustained coverage.

The rate of new cases of a condition occurring in a population over a specified time period. Distinct from prevalence, which counts all existing cases regardless of when they began.

The process by which a patient (or legal guardian) receives and understands information about a proposed treatment's benefits, risks, alternatives, and right to refuse, then voluntarily agrees to proceed. Required before initiating any medication trial.

A neurodevelopmental disorder characterized by significant limitations in intellectual functioning and adaptive behavior.

Inwardly directed emotional problems including anxiety, depression, and withdrawal.

A framework for understanding how overlapping social identities (race, gender, disability, socioeconomic status) interact to create unique experiences of disadvantage or discrimination.

Brand name for extended-release guanfacine, a selective alpha-2A adrenergic agonist. FDA-approved for ADHD as monotherapy and adjunctive to stimulants.

The dose-response relationship where both too little and too much of a neurotransmitter impair function. Optimal performance occurs at intermediate levels.

Incidence Rate Ratio. A measure comparing the rate of events between exposed and unexposed groups in epidemiological studies.

A heightened proneness to anger or frustration, seen across many psychiatric conditions.

Intention-to-Treat analysis. A method analyzing all participants as originally assigned, regardless of adherence or protocol completion.

Delayed-release methylphenidate designed for evening dosing (6:30-9:30 PM). The only stimulant designed for evening administration to provide coverage upon waking.

Brand name for extended-release clonidine, a non-selective alpha-2 agonist. FDA-approved for ADHD as monotherapy and adjunctive to stimulants.

An anticonvulsant and mood stabilizer (Lamictal) particularly effective for bipolar depression. Slow titration required to minimize rash risk.

The l-enantiomer of amphetamine, with more pronounced noradrenergic effects contributing to arousal and cardiovascular tone.

A prodrug of dextroamphetamine that is inactive until metabolized. Provides smoother onset and lower abuse potential. Brand name: Vyvanse.

A mood stabilizer used for bipolar disorder maintenance and acute mania. Narrow therapeutic window requiring regular blood level monitoring.

A research design that follows the same participants over an extended period to track changes and outcomes.

Least Restrictive Environment. The IDEA principle that students with disabilities should be educated with non-disabled peers to the maximum extent appropriate.

The ongoing treatment period after initial stabilization, focused on sustaining gains and preventing relapse.

A mood disorder characterized by persistent sad mood or loss of interest, with functional impairment.

Monoamine Oxidase. An enzyme that breaks down neurotransmitters (dopamine, norepinephrine, serotonin) inside neurons.

Monoamine Oxidase Inhibitor. A class of antidepressant medications rarely used due to dietary restrictions and interaction risks.

Consciously or unconsciously concealing symptoms to appear neurotypical, common in certain populations.

Manifestation Determination Review. A process to determine whether a student's behavior is related to their disability before disciplinary action.

Systematic clinical practice of administering validated patient-reported outcome measures at regular intervals to track symptom trajectory and inform treatment adjustments collaboratively. Components include: measure administration, clinician review, patient-clinician discussion, and documented treatment modification based on symptom progress.

A hormone supplement commonly used to address sleep difficulties associated with psychiatric conditions and medications.

A research method that uses genetic variants as natural experiments to test whether an exposure (like smoking or lead) truly causes an outcome (like ADHD), rather than just correlating with it. Helps distinguish genuine environmental risk factors from genetic confounding.

A statistical method that combines results from multiple studies to produce a more precise estimate of a treatment's effect.

A substance produced when the body chemically processes (metabolizes) a drug or other compound. Metabolites may be active, inactive, or potentially harmful, and their levels can vary depending on individual enzyme activity.

A person's drug-processing capacity based on their genetic enzyme activity (poor, intermediate, normal, ultrarapid).

Extended-release methylphenidate using a beaded system with a 30:70 immediate-to-delayed release ratio.

A stimulant medication that enhances attention and executive function by blocking the reuptake of dopamine and norepinephrine. Brand names include Ritalin, Concerta, Focalin, and Daytrana.

A formulation combining d-amphetamine and l-amphetamine in a 3:1 ratio. Brand name: Adderall.

A wakefulness-promoting agent sometimes used off-label for attention disorders and excessive daytime sleepiness.

A change to what a student is expected to learn or demonstrate, altering content or performance standards. Contrast with accommodation, which changes how material is delivered without altering expectations.

Therapeutic approach using motivational interviewing techniques to increase client intrinsic motivation for behavior change and treatment adherence. Involves exploring ambivalence, eliciting change talk, and supporting autonomy rather than directive advice-giving.

A collaborative conversation style that strengthens a person's own motivation for and commitment to change.

Multimodal Treatment Study of Children with ADHD. A landmark NIMH-funded trial comparing medication, behavioral therapy, combined treatment, and standard care.

Multi-Tiered Systems of Support. A framework providing increasingly intensive interventions based on student needs.

Gathering diagnostic information from multiple sources to improve accuracy.

Triple-bead extended-release mixed amphetamine salts. The longest-acting oral amphetamine formulation, with duration up to 16 hours.

A rating scale designed to measure symptoms of a specific disorder.

Noradrenergic and Specific Serotonergic Antidepressant. A drug class represented by mirtazapine, which blocks alpha-2 autoreceptors and specific serotonin receptors (5-HT2A, 5-HT2C, 5-HT3) to enhance norepinephrine and serotonin transmission.

The probability that a negative test result correctly identifies someone who does not have the condition.

Norepinephrine Transporter. The protein that recycles norepinephrine from the synapse. Blocked by both stimulants and some non-stimulants.

A method that compares multiple treatments simultaneously by linking all available trials.

A category of conditions with onset during the developmental period, arising from differences in brain maturation. Includes ADHD, autism, intellectual disability, and learning disorders.

The pattern of brain maturation and cognitive development from early childhood through young adulthood.

The brain's ability to reorganize and form new neural connections throughout life in response to experience.

Natural steroid hormones produced by the body (particularly allopregnanolone from progesterone metabolism) that modulate extrasynaptic GABA-A receptors, providing baseline neural inhibition independent of synaptic transmission. Zuranolone, an oral synthetic neurosteroid, FDA-approved for postpartum depression, demonstrates mechanism distinct from benzodiazepines.

A chemical messenger released by neurons to transmit signals across synapses. The neurotransmitters most relevant to ADHD are dopamine and norepinephrine (catecholamines), which regulate prefrontal cortex function, reward processing, and attention.

National Institute for Health and Care Excellence (UK). Publishes evidence-based guidance for mental health and neurodevelopmental disorder management.

National Institute of Mental Health. The lead U.S. federal agency for research on mental disorders.

Number Needed to Harm. The number of patients who must receive a treatment for one additional patient to experience a specific adverse effect.

Number Needed to Treat. The number of patients who must receive a treatment for one additional patient to benefit compared to placebo. Lower is better.

Failure to follow a prescribed treatment regimen, whether by missing doses, stopping medication early, or not attending therapy sessions. Common in ADHD and associated with poorer outcomes. Often driven by side effects, forgetfulness, stigma, or cost.

A medication used to treat ADHD that does not belong to the stimulant class. Includes atomoxetine, guanfacine, clonidine, and viloxazine. Often considered when stimulants are ineffective, poorly tolerated, or contraindicated.

A neurotransmitter involved in attention, arousal, and the stress response. Key pathway: locus coeruleus → widespread cortical projections, especially prefrontal cortex. Strengthens signal in PFC networks by acting on α2A-adrenoceptors. Targeted by atomoxetine, guanfacine, and clonidine. Under high stress, excess norepinephrine activates α1 receptors that degrade PFC function.

A tricyclic antidepressant used for depression, anxiety, and chronic pain conditions. Metabolite of amitriptyline with improved side effect profile.

Relating to the classification of diseases and disorders. A nosological question asks whether a condition belongs in the diagnostic system as its own distinct entity.

The brain's reward center, which drives motivation and is central to understanding reward processing and motivation across conditions.

A sleep disorder where the airway repeatedly collapses during sleep, causing fragmented sleep and daytime impairment.

Obsessive-Compulsive Disorder. A condition involving intrusive thoughts (obsessions) and repetitive behaviors (compulsions).

Oppositional Defiant Disorder. A behavioral disorder characterized by angry/irritable mood, argumentative/defiant behavior, and vindictiveness.

A measure of association between an exposure and an outcome, commonly used in case-control studies.

Prescribing an FDA-approved medication for a condition, age group, or dose not specified in its official labeling.

Other Health Impairment. An IDEA eligibility category for students whose health conditions—including heightened alertness to environmental stimuli—adversely affect educational performance.

An atypical antipsychotic (Zyprexa) used for bipolar disorder and psychosis. Higher metabolic risk (weight gain, diabetes) than some other antipsychotics.

A study design in which both the researcher and participant know which treatment is being administered. Useful for assessing real-world tolerability and long-term safety but more vulnerable to expectancy bias than blinded designs.

A learning process where the likelihood of a behavior changes based on its consequences—increasing with reinforcement and decreasing with punishment.

A behavioral disorder characterized by a pattern of angry/irritable mood, argumentative behavior, and defiance toward authority figures.

A prefrontal region involved in decision-making, reward evaluation, and social behavior.

Osmotic-Release Oral System. A drug delivery mechanism for extended-release formulations.

A drug delivery technology (used in OROS methylphenidate) that uses an osmotic gradient to push medication through a laser-drilled hole in an outer shell, producing a controlled ascending release profile over 10 to 12 hours.

Organizational Skills Training. A structured intervention teaching children and adolescents to manage materials, time, and task planning.

An SSRI antidepressant (Paxil) with notable strong CYP2D6 inhibitor properties, affecting metabolism of many other medications. Used for anxiety and depression.

Preschool ADHD Treatment Study. A landmark NIH trial evaluating medication treatment in preschool-age children.

Prescription Drug Monitoring Program. A state database tracking controlled substance prescriptions to prevent misuse.

Pediatric Quality of Life Inventory. A measure of health-related quality of life in children and adolescents.

Prefrontal cortex. The anterior region of the frontal lobe responsible for executive functions including sustained attention, working memory, behavioral inhibition, planning, and organization. Exquisitely sensitive to catecholamine levels, following an inverted-U dose-response curve.

How a drug affects the body, including its mechanism of action and therapeutic effects.

How a person's genetic makeup affects the way their body processes a drug.

How the body absorbs, distributes, metabolizes, and eliminates a drug. Determines how long and how strongly a medication works.

Brief, burst-like dopamine release that signals prediction errors and drives learning and reinforcement.

When a drug interaction changes a person's metabolizer status (e.g., converting a normal metabolizer to a functional poor metabolizer).

A presentation that looks identical to a disorder from the outside but has a different underlying cause.

The observable characteristics of an individual resulting from the interaction of genotype and environment. In clinical use, the pattern of symptoms and traits a person displays.

Patient Health Questionnaire-9. A brief screening and severity measure for depression.

Present Levels of Academic Achievement and Functional Performance. The IEP section documenting a student's current abilities and needs.

An inert substance or sham intervention administered in clinical trials to serve as a comparison against the active treatment. Allows researchers to distinguish true drug effects from psychological or contextual influences.

An improvement in symptoms attributable to the expectation of benefit rather than the treatment's specific mechanism.

A numerical summary of genetic risk for a condition based on the cumulative effect of multiple common gene variants.

An overnight sleep study that monitors breathing, oxygen levels, and brain activity during sleep.

The probability that a positive test result correctly identifies someone who has the condition.

The brain region behind the forehead responsible for attention, planning, working memory, and impulse control. Central to understanding many psychiatric conditions.

An automatic, reflexive behavioral response that occurs before conscious decision-making, such as blurting out an answer, grabbing an object, or interrupting a conversation. Suppressing prepotent responses requires intact behavioral inhibition.

The tendency to continue an unchanged medication regimen despite evidence that adjustment is needed.

The DSM-5 relabeling of disorder "subtypes" to "presentations", reflecting that they are fluid and can change over time.

The proportion of a population found to have a condition at a specific point in time (point prevalence) or over a defined period (period prevalence). Distinct from incidence, which counts new cases only.

Pro re nata (as needed). A dosing strategy where medication is taken only when symptoms arise rather than on a fixed schedule. Common for acute anxiety management with benzodiazepines or hydroxyzine.

A pharmacologically inactive (or minimally active) compound that must be metabolized in the body to release the active drug.

A statistical technique that creates balanced comparison groups by matching treated and untreated participants on relevant characteristics.

A study design that follows a defined group forward in time to observe outcomes.

Polygenic Risk Score. A numerical summary of genetic risk for a condition based on the cumulative effect of multiple common gene variants.

Apparent treatment failure that is actually caused by non-adherence, untreated comorbidities, or pharmacokinetic mismatch.

Sympathomimetic decongestant available over the counter that can trigger or worsen anxiety symptoms through noradrenergic activation. Important to screen for in patients presenting with new or worsening anxiety, particularly panic-like symptoms.

Providing patients and families with information about a diagnosis, its treatment, and management strategies.

A structured academic and cognitive evaluation designed to identify specific learning disabilities.

Observable restlessness with purposeless or semi-purposeless motor activity driven by inner tension. Distinguished from akathisia (which is specifically medication-induced) and from anxiety-driven fidgeting.

Post-Traumatic Stress Disorder. A condition that can develop after exposure to traumatic events.

A deep brain structure involved in motor control and habit learning.

Brand name for viloxazine extended-release, the newest FDA-approved non-stimulant for ADHD. A norepinephrine reuptake inhibitor with serotonin-modulating properties.

Corrected QT interval. A measurement on ECG related to heart rhythm. Prolongation is a safety concern with some medications.

Abnormal lengthening of the heart's electrical recovery interval, increasing risk of dangerous arrhythmias.

An atypical antipsychotic (Seroquel) used for bipolar disorder, psychosis, and as a sleep aid due to sedating properties. Lower risk of extrapyramidal side effects.

Extended-release methylphenidate in liquid suspension. One of the few stimulant formulations available for patients who cannot swallow pills.

A study design in which participants are randomly assigned to receive either the experimental intervention or a control condition. Considered the gold standard for evaluating treatment efficacy because randomization minimizes selection bias.

Randomized Controlled Trial. The gold standard study design for evaluating treatment efficacy.

A temporary flare of symptoms that are more intense than the person's unmedicated baseline, occurring as a medication wears off.

The return of symptoms after a period of improvement or remission.

A sustained period where symptoms fall below clinical thresholds and functional impairment is minimal.

A behavioral technique where a privilege or token is removed following an undesired behavior.

A neurological condition causing uncomfortable sensations and an urge to move the legs.

The process by which a presynaptic neuron recycles neurotransmitters from the synapse back into the cell.

A drug that blocks the transporter proteins responsible for recycling neurotransmitters, keeping them active in the synapse longer.

How rewarding or motivating the brain perceives a given task or stimulus to be.

The ratio of event probability in the exposed group to the unexposed group.

An atypical antipsychotic used for irritability, aggression, and psychotic symptoms across psychiatric conditions. Lower propensity for metabolic side effects than older antipsychotics.

Brand name for immediate-release methylphenidate. Duration approximately 3-5 hours, requiring multiple daily doses.

Extended-release methylphenidate using a multi-particulate beaded system with a 50:50 immediate-to-delayed release ratio.

The gold-standard framework in psychiatry for establishing whether a diagnosis is scientifically valid. The five criteria are: consistent clinical presentation across settings and cultures, familial aggregation, laboratory correlates, predictable course, and treatment response.

Response to Intervention. A multi-tiered approach to early identification and support of students with learning and behavior needs.

Repetitive Transcranial Magnetic Stimulation; neuromodulation technique applying magnetic pulses to scalp to modulate brain activity, typically targeting dorsolateral prefrontal cortex. FDA-approved for treatment-resistant depression; efficacy in anxiety disorders remains investigational with mixed results.

External support structures that compensate for symptoms. When scaffolding is removed, symptoms become more apparent.

Screen for Child Anxiety Related Disorders. A screening tool for anxiety in children and adolescents.

A DEA classification for drugs with high abuse potential but accepted medical use, requiring special prescribing controls.

Alternative evidence-based treatment for an anxiety disorder when first-line interventions have been inadequately trialed or failed. Examples include buspirone augmentation, alternative SSRI/SNRI agents, or specific psychotherapy protocols for particular presentations.

Selective MAO-B inhibitor at low doses (used for Parkinson's disease) that becomes a non-selective MAOI at higher doses. The transdermal patch (Emsam) bypasses dietary tyramine restrictions at the lowest dose, offering a theoretically safer MAOI option.

The ability of a test to correctly identify those who have a condition (true positive rate).

Excessive fear or worry about being separated from attachment figures.

A neurotransmitter involved in mood regulation, anxiety, impulse control, and sleep. Key pathway: raphe nuclei → widespread projections throughout the cortex, limbic system, and brainstem. Primary target of SSRIs and SNRIs. Relevant to ADHD through comorbid mood and anxiety disorders.

A potentially life-threatening condition caused by excessive serotonin activity, characterized by agitation, rapid heart rate, fever, muscle rigidity, and clonus.

Serotonin reuptake transporter, the membrane protein that SSRIs and SNRIs target to block reuptake of serotonin from synaptic space back into presynaptic neurons, increasing serotonin availability. The 5-HTTLPR polymorphism in the gene encoding SERT has no validated clinical utility despite earlier candidate gene claims.

An SSRI antidepressant (Zoloft) commonly used for anxiety disorders, depression, OCD, and PTSD across age groups.

A collaborative process where clinicians and patients jointly make treatment decisions.

Syndrome of Inappropriate Antidiuretic Hormone secretion. A potentially serious adverse effect of SSRIs and SNRIs causing dilutional hyponatremia; risk is highest in elderly patients and those on diuretics.

In neuroscience, the clarity of relevant neural signals relative to background neural activity.

Specific Learning Disorder. A neurodevelopmental disorder affecting the acquisition of academic skills despite adequate instruction.

The normal cycling through light sleep, deep sleep, and REM sleep throughout the night.

The time it takes to transition from full wakefulness to sleep after lights out. Prolonged sleep onset latency is a common side effect of stimulant medications and a frequent concern in ADHD management.

Sequential Multiple Assignment Randomized Trial. A study design that adapts treatment based on patient response at each stage.

Standardized Mean Difference. A measure of effect size: 0.2 = small, 0.5 = medium, 0.8+ = large.

Swanson, Nolan, and Pelham Rating Scale, Version IV. A widely used symptom rating scale based on DSM criteria.

Single Nucleotide Polymorphism. A variation at a single DNA position, the most common type of genetic variation.

Serotonin-Norepinephrine Reuptake Inhibitor. A class of antidepressants that block reuptake of both serotonin and norepinephrine.

An anxiety disorder characterized by intense fear of social situations and scrutiny by others.

A neurodevelopmental disorder affecting the acquisition of academic skills despite adequate instruction.

The ability of a test to correctly identify those who do not have a condition (true negative rate).

Selective Serotonin Reuptake Inhibitor. A class of antidepressant medications commonly used for anxiety and depression.

Sequenced Treatment Alternatives to Relieve Depression. Landmark NIMH-funded trial (N=4,041) demonstrating that most patients require multiple treatment steps to achieve remission, with diminishing response rates at each step.

The point where the drug level in the blood stabilizes, meaning you can judge whether a dose is working. Reached after about 5 half-lives.

Treatment matching framework where intensity and invasiveness increase stepwise based on symptom severity and treatment response. Lower-intensity steps (psychoeducation, self-help) are offered first; progression to higher-intensity steps (full psychotherapy, medication) occurs only if lower steps prove insufficient.

A rare, severe skin reaction to medications requiring immediate medical attention.

A class of medications (methylphenidate and amphetamine formulations) that increase synaptic dopamine and norepinephrine by blocking reuptake transporters (DAT and NET). First-line pharmacotherapy for ADHD with the largest evidence base for efficacy.

Brand name for atomoxetine, a selective norepinephrine reuptake inhibitor (NRI). The first FDA-approved non-stimulant for ADHD. Not a controlled substance.

A deep brain structure involved in reward, motivation, and habit formation. Includes the caudate nucleus and putamen.

A standardized assessment format where clinicians ask predetermined questions in a specific order to improve diagnostic reliability.

Substance Use Disorder. A diagnosis for problematic patterns of substance use leading to clinically significant impairment.

Thoughts about or preoccupation with ending one's own life, ranging from passive wishes to active planning.

A medication formulation that delivers its active ingredient at a controlled rate over a prolonged period, similar to extended-release. Often used interchangeably with extended-release in clinical literature.

A drug that stimulates the sympathetic nervous system (fight-or-flight response).

The junction between two neurons where chemical signals (neurotransmitters) are transmitted across a tiny gap from the sending cell to the receiving cell.

The amount of neurotransmitter present in the synapse and available to bind receptors.

A comprehensive, structured synthesis of all available evidence on a specific clinical question.

Rapid decrease in drug response after repeated doses within a short period.

The gradual reduction of a medication dose over days or weeks rather than abrupt discontinuation. Tapering reduces the risk of withdrawal symptoms or rebound effects, particularly with alpha-2 agonists such as clonidine and guanfacine.

Tricyclic Antidepressant. An older class of antidepressants that block reuptake of norepinephrine and serotonin.

A substance that causes birth defects when exposure occurs during pregnancy.

Quality of the working relationship between clinician and patient, characterized by agreed-upon treatment goals, collaboration on interventions, and mutual emotional connection. Strong alliance independently predicts better treatment outcomes across psychotherapy and pharmacotherapy.

The margin between an effective dose and a toxic dose. A narrow therapeutic index means a dangerously small margin.

The dose range between minimum effective concentration and toxic concentration.

Treatment approach pursued after first-line and second-line agents or therapies have been adequately trialed without remission. Often includes higher-dose augmentation, combination pharmacotherapy, or novel agents like ketamine or psychedelic-assisted therapies.

A neurological deficit in temporal processing. Not willful disregard for time, but genuine difficulty perceiving time intervals.

The process of gradually adjusting a medication dose to find the optimal balance between efficacy and side effects.

A reinforcement system where individuals earn tokens for desired behaviors that can be exchanged for rewards.

Baseline, sustained dopamine levels that set overall arousal and readiness for action.

A neurodevelopmental disorder characterized by multiple motor tics and at least one vocal tic persisting for more than one year.

Test of Variables of Attention. A continuous performance test measuring attention and impulse control.

The planned transfer of clinical responsibility from pediatric to adult healthcare providers.

An event or series of events that is physically or emotionally harmful and has lasting adverse effects on functioning.

Structured, evidence-based decision pathway guiding sequential treatment choices based on patient response at each step. Typically organized as first-line, second-line, and treatment-resistant options with defined criteria for advancing.

The degree to which an intervention is delivered as intended in its original design.

A clinically significant reduction in symptoms following an intervention.

Failure to achieve remission despite adequate trials (adequate dose, adequate duration per Domschke staging criteria) of at least two first-line or second-line psychopharmacological agents. Triggers evaluation for third-line strategies and reassessment of diagnosis.

A student who is both gifted and has a disability.

A white matter tract connecting emotion centers (amygdala, limbic structures) to self-regulation centers (prefrontal cortex). When degraded, the prefrontal cortex has reduced ability to modulate emotional reactions.

Vanderbilt ADHD Diagnostic Rating Scale. A free, validated rating scale for attention disorder diagnosis and monitoring.

An anticonvulsant and mood stabilizer (Depakote) used for bipolar disorder and seizure prevention. Requires monitoring for liver function and blood counts.

A free, publicly available ADHD rating scale system with parent and teacher forms. Screens for core ADHD symptoms and common comorbidities (ODD, conduct disorder, anxiety, depression). Widely used in primary care.

An SNRI antidepressant (Effexor) used for depression, anxiety, and chronic pain. At lower doses acts primarily on serotonin; at higher doses adds significant norepinephrine reuptake inhibition.

A non-stimulant medication (Qelbree) approved for attention disorders. Functions primarily as a norepinephrine reuptake inhibitor with additional serotonin modulating activity. Onset in 1–2 weeks.

Vesicular Monoamine Transporter 2. The protein that packages dopamine and norepinephrine into storage vesicles inside neurons.

Brand name for lisdexamfetamine, a prodrug that requires enzymatic cleavage in the bloodstream to release active d-amphetamine. Lower abuse potential due to prodrug mechanism.

Time required after discontinuing one medication before starting another, allowing the first drug to clear sufficiently to avoid interactions. Critical when switching between MAOIs and serotonergic agents (typically 14 days for MAOIs, 5 half-lives for the prior agent).

Brand name for bupropion, a norepinephrine-dopamine reuptake inhibitor used off-label for ADHD. Also FDA-approved for depression and smoking cessation.

Weiss Functional Impairment Rating Scale. A validated measure of functional impairment across multiple domains.

The wiring that connects brain areas to each other. Disruptions in white matter integrity are associated with various psychiatric conditions.

The cognitive system that temporarily holds and manipulates information needed for complex tasks like reasoning, comprehension, and learning. A core executive function impaired in many individuals with ADHD. Depends on prefrontal cortex networks modulated by dopamine (D1 receptors) and norepinephrine (α2A receptors).