What is adhd?
Quick answer
ADHD is a neurodevelopmental disorder marked by ongoing patterns of inattention, hyperactivity, impulsivity, or a mix of these that interfere with daily life. In Canada, the term appears in assessment and diagnosis using DSM-5-TR or ICD-11 language, and it can affect treatment planning, school supports, work accommodations and some benefits paperwork.
ADHD is a defined medical term
ADHD stands for attention-deficit/hyperactivity disorder. It is a neurodevelopmental disorder, not a character flaw or a lack of effort. The core issue is a persistent pattern of attention problems, hyperactive or restless behaviour, impulsive behaviour, or a combination, severe enough to impair functioning in more than one part of life.
In Canadian care, clinicians usually define ADHD using standard diagnostic language from the DSM-5-TR or the ICD-11. The World Health Organization lists ADHD in ICD-11 as code 6A05, and Canadian clinicians may use that coding language in records, referrals, forms and benefits paperwork. If you want the coding side explained, see What does ICD-11 6A05 mean?.
It shows up in daily functioning
ADHD matters because it affects functioning, not just attention span. Adults may struggle with starting tasks, finishing routine work, managing time, remembering steps, regulating impulses, or staying organized. Teens may show similar patterns at school, at home and socially.
A diagnosis is not based on one bad week or on being busy, stressed or bored. Canadian guidelines and diagnostic manuals expect symptoms to be ongoing, present since childhood in some form, and linked to real impairment. Problems can overlap with sleep issues, anxiety, depression, learning disorders, trauma, substance use or medical conditions, so assessment looks at the full picture.
ADHD can coexist with anxiety, depression, or substance-use concerns, but symptoms and causes vary from person to person. If you or your teen needs help now because of thoughts of self-harm, suicide, or a mental health crisis, call or text 9-8-8 in Canada, or call 911.
- Attention problems, such as losing track, missing details or drifting off
- Hyperactivity or restlessness, such as feeling driven, fidgety or unable to settle
- Impulsivity, such as interrupting, acting quickly or having trouble waiting
- Functional impact at school, work, home, finances, relationships or driving
In Canada, the term appears in assessment
In practice, the word ADHD appears first in an assessment, not in a screener result. A clinician gathers history, current symptoms, evidence of impairment, developmental background and possible other explanations before deciding whether the presentation is consistent with ADHD. Not every assessment results in an ADHD diagnosis.
For adults, ADHD assessment may be offered virtually or in person depending on the province, the clinician's scope, and the service model. Assessments generally involve a clinical interview, review of symptoms and impairment, relevant history, and consideration of other explanations before a clinician decides whether the presentation is consistent with ADHD.
A free online screener can help you decide whether an assessment may be worth discussing, but it is screening only and does not diagnose ADHD. If you are wondering whether a virtual assessment is accepted, see Are virtual ADHD assessments legitimate in Canada?.
| Stage | How the term is used |
|---|---|
| Screening | A screening result may suggest ADHD traits, but it does not diagnose. |
| Assessment | A licensed clinician assesses whether symptoms and impairment fit ADHD criteria. |
| Records | A diagnosis letter or report may use DSM-5-TR wording or ICD-11 coding. |
| Follow-up | The term guides treatment planning, monitoring and accommodation paperwork. |
It can affect treatment, school, work and benefits
Once ADHD is identified, the term becomes practical. It can shape treatment planning, which may include education, skills strategies, therapy, coaching, workplace or school accommodations, and in some cases prescription treatment if clinically appropriate and legally permitted in the province where care is provided.
For adults, the diagnosis may support accommodation discussions at work or post-secondary school. For teens, it may be relevant to school planning and parent-clinician communication. Documentation needs vary by institution, employer or benefits provider, so confirm what form or wording they require.
The Canada Revenue Agency lists ADHD among examples of mental functions that can be relevant to the Disability Tax Credit, but eligibility depends on the person’s impairment meeting the legal test and on certification by a qualified medical practitioner. A diagnosis alone does not automatically qualify someone.
Related terms you may see
ADHD is the umbrella term. Other terms break down subtype language, coding language or common difficulties linked to ADHD.
- What is inattentive adhd?
- What is executive dysfunction?
- What does ICD-11 6A05 mean?
- What is stigma in mental health care?
Common questions
Related questions, answered
No. Ordinary distraction, stress or high energy are not the same as ADHD. ADHD is a clinical term used when a persistent pattern of symptoms causes meaningful impairment in daily functioning and is better explained by ADHD than by another condition or life situation.
Yes. Adults can be assessed for ADHD in Canada by licensed health professionals authorized to assess ADHD within their scope and province, using a structured clinical process. The assessment usually reviews childhood history, current symptoms, impairment across settings and other possible explanations. A screener can suggest whether assessment may be useful, but it does not diagnose.
No. Treatment planning is individualized. Education, skills supports, therapy, coaching, school or work accommodations and lifestyle changes may all be part of care. If treatment is clinically appropriate and legally permitted in your province, a licensed clinician may also discuss prescription options, including stimulant medications or non-stimulant options.
Sometimes, but not automatically. In Canada, accommodation decisions at school or work depend on functional impact and the documentation requested. For tax benefits such as the Disability Tax Credit, eligibility depends on the legal criteria being met and certification by a qualified medical practitioner, not on the diagnosis alone.
Helpful next steps
References
- 1.World Health Organization, ICD-11 for Mortality and Morbidity Statistics, 6A05 Attention deficit hyperactivity disorder View source ↗
- 2.Centre for Addiction and Mental Health, Adult ADHD View source ↗
- 3.CADDRA, Canadian ADHD Practice Guidelines View source ↗
- 4.Canada Revenue Agency, Disability Tax Credit View source ↗
- 5.Government of Canada, 9-8-8: Suicide Crisis Helpline View source ↗
This article is for educational purposes only and is not medical advice, diagnosis, or treatment. Always consult a licensed healthcare professional about your individual situation. If you are in crisis or thinking about self-harm, call or text 9-8-8, Canada’s Suicide Crisis Helpline, at any time.
Finding Focus uses AI tools to help research and draft some articles. Every article is edited and fact-checked by the Finding Focus team before publication. See our editorial and medical review policy.
