Reference

ADHD glossary: the terms you will hear in an evaluation, a school meeting, or a doctor’s office

Short, plain definitions of ${terms.length} terms, written by a clinician who uses them daily. Where a term connects to a longer article on this site, it is linked.

ADHD (Attention-Deficit/Hyperactivity Disorder)

A neurodevelopmental condition defined in the DSM-5-TR by persistent inattention and/or hyperactivity-impulsivity that begins in childhood, appears in more than one setting, and interferes with functioning. Three presentations: predominantly inattentive, predominantly hyperactive-impulsive, and combined.

ADD

An older term from DSM-III for what is now called ADHD, predominantly inattentive presentation. Still used informally; no longer a separate diagnosis.

Executive function

The set of mental skills that manage behavior toward a goal: working memory, inhibition, task initiation, planning, organization, time management, and emotional regulation. ADHD is increasingly understood as a disorder of executive function rather than of attention alone. Read more →

Working memory

The ability to hold information in mind while using it: a phone number, the steps of an instruction, the point you were about to make. Weak working memory explains much of the forgetting mid-task that people with ADHD describe. Read more →

Time blindness

Difficulty sensing the passage of time and estimating how long things take. People with ADHD tend to experience time as "now" and "not now," which drives chronic lateness and last-minute work. Read more →

Hyperfocus

Intense, prolonged concentration on something interesting, often to the exclusion of everything else. Common in ADHD and frequently misread as evidence against the diagnosis; the issue is regulating attention, not producing it. Read more →

Rejection sensitive dysphoria (RSD)

Extreme emotional pain in response to perceived criticism or rejection. Not a formal diagnosis, but a widely reported ADHD experience related to emotional dysregulation. Read more →

Emotional dysregulation

Emotions that arrive faster, bigger, and last longer than the situation warrants, and are harder to bring back down. Not in the DSM criteria for ADHD, but present in a majority of people with the condition. Read more →

TOVA (Test of Variables of Attention)

A computerized continuous performance test lasting about 21 minutes that measures response time, variability, errors of omission (inattention), and errors of commission (impulsivity), compared with age and sex norms. One objective component of a comprehensive evaluation; never diagnostic on its own.

Rating scales

Standardized questionnaires completed by the patient and by others who know them (parents, teachers, partners). Examples include the Conners, Vanderbilt, ASRS, and BRIEF. They quantify symptoms across settings.

Collateral information

Input from people other than the patient: teachers, parents, partners, old report cards. Required for a sound diagnosis because ADHD must be shown in more than one setting and to have started in childhood.

Differential diagnosis

The process of ruling in or out other conditions that produce the same symptoms: anxiety, depression, trauma, sleep disorders, learning disabilities, thyroid problems, substance use. The step that separates an evaluation from a screening. Read more →

Comorbidity

A second condition occurring alongside ADHD. Anxiety, depression, learning disorders, and sleep disorders are the most common. Most adults with ADHD have at least one.

Screening vs. evaluation

A screening is a brief questionnaire that indicates whether further assessment is warranted. An evaluation is a multi-hour clinical process that produces a diagnosis. Screenings are free and quick; they are not diagnoses. Read more →

504 plan

A plan under Section 504 of the Rehabilitation Act that provides accommodations (extended time, preferential seating, reduced-distraction testing) to a student with a disability in general education. Requires documentation of a disability that substantially limits a major life activity; ADHD qualifies. Read more →

IEP (Individualized Education Program)

A legal document under IDEA for students who need specialized instruction, not just accommodations. ADHD students typically qualify under the category Other Health Impairment (OHI). More intensive than a 504 plan and requires a formal eligibility process.

Accommodations

Changes to how a student or employee does the work without changing the standard: extended time, a quiet room, notes provided, flexible deadlines. Distinct from modifications, which change what is expected.

Stimulant medication

Methylphenidate-based (Ritalin, Concerta) and amphetamine-based (Adderall, Vyvanse) medications; the most effective and most studied ADHD treatment. Prescribed by physicians, not by psychologists or counselors.

Non-stimulant medication

Atomoxetine (Strattera), viloxazine (Qelbree), guanfacine (Intuniv), and clonidine. Slower onset, generally smaller effect than stimulants, useful when stimulants are not tolerated or appropriate.

Body doubling

Working alongside another person, in the room or on video, to make it easier to start and sustain a task. A widely used ADHD strategy that borrows external structure.

Task initiation

The executive skill of starting. Difficulty initiating, especially on boring or multi-step tasks, is one of the most disabling features of adult ADHD and is often mistaken for laziness or procrastination. Read more →

Masking

Effortful strategies that hide symptoms: over-preparing, perfectionism, people-pleasing, working late to catch up. Common in women and in high-achieving adults, and a major reason ADHD is diagnosed late. Read more →

LPC (Licensed Professional Counselor)

A master’s or doctoral-level mental health clinician licensed by the state. In Michigan and many other states, LPCs may conduct and interpret standardized ADHD assessment. Scope varies by state. Read more →

Superbill

An itemized receipt with diagnostic and procedure codes that a patient can submit to an insurer for out-of-network reimbursement. Read more →

Written and reviewed by Dr. Andrew Wichterman, PhD, LPC. Last updated September 9, 2026.