Who can diagnose ADHD in Ontario?

Physicians, nurse practitioners and psychologists are the professions authorized to communicate an ADHD diagnosis in Ontario

Ontario is explicit about who may diagnose. Section 27 of the Regulated Health Professions Act, 1991 lists communicating to a person a diagnosis identifying a disease or disorder as the cause of their symptoms as a controlled act, and each profession's own Act says whether its members are authorized to perform it. For ADHD, three professions are.

• Physicians, including family doctors and psychiatrists, are licensed by the College of Physicians and Surgeons of Ontario (CPSO) and authorized under the Medicine Act, 1991. A family doctor can diagnose adult ADHD directly or refer to a psychiatrist; both are insured by OHIP.
• Nurse practitioners, registered with the College of Nurses of Ontario (CNO) in the extended class, are authorized to communicate a diagnosis under section 5.1 of the Nursing Act, 1991. Since 2017, NPs who have completed CNO-approved controlled substances education can also prescribe the stimulant medications used for ADHD.
• Psychologists and psychological associates, registered with the College of Psychologists and Behaviour Analysts of Ontario (CPBAO, renamed from the College of Psychologists of Ontario in 2024), are authorized under section 4 of the Psychology Act, 1991 to communicate a diagnosis of a psychological disorder. They assess and diagnose ADHD within their declared competence but do not prescribe.

Other regulated professionals, including registered psychotherapists, social workers and occupational therapists, can screen, support and treat but cannot communicate an ADHD diagnosis. Whoever assesses you, the diagnosis rests on a structured interview against DSM-5-TR criteria, childhood evidence, rating scales and a check for other explanations, and a careful assessment can conclude that ADHD is not the explanation.

Ontario has no provincial adult ADHD clinic, so the OHIP route runs through primary care and psychiatry

Hospital child and youth mental health programs assess ADHD in young people, but no Ontario-wide adult ADHD service exists. For an adult the insured route is a family physician or nurse practitioner who assesses you or refers you to a psychiatrist. Family Health Teams, Community Health Centres and NP-led clinics are all publicly funded, and Health Care Connect registers people without a provider for one accepting patients.

Hospital psychiatry departments and community mental health agencies take referrals but prioritize severe illness, so an uncomplicated adult ADHD question is usually returned to primary care. Psychologists in private practice charge fees that OHIP does not cover, though extended health plans often reimburse part; psychologists employed in hospital programs assess within those programs rather than on request.

Only physicians and nurse practitioners can prescribe, and stimulant prescriptions are tracked through the Narcotics Monitoring System

Ontario does not use duplicate prescription pads. Instead, the Narcotics Safety and Awareness Act, 2010 designates the stimulant medications used for ADHD as monitored drugs, and every dispense is reported by the pharmacy to the Narcotics Monitoring System, which the Ministry of Health uses to identify unusual prescribing or dispensing patterns.

Nurse practitioners must have completed CNO-approved education in controlled substances before prescribing these medications, and a pharmacist can confirm an NP's status on CNO's Find a Nurse register. The detail is in Can a nurse practitioner prescribe ADHD medication in Ontario?.

A diagnosis from one professional is used by the others, with some limits

A psychologist's report cannot start medication on its own; it goes to a physician or nurse practitioner, who reviews it and decides on treatment. A physician's or NP's diagnosis supports continuing care with your family doctor, accommodations at work or school, and non-medication support such as cognitive behavioural therapy or coaching. In Ontario, Finding Focus offers CBT and ADHD coaching with registered social workers through its therapy program.

The receiving professional wants to see the criteria used, the childhood evidence, the conditions ruled out, and the assessor's registration number. A family doctor is not obliged to take over prescribing after a private diagnosis, so ask in advance and send the report ahead; if they decline, ongoing care can continue with the clinic that made the diagnosis. Can a family doctor continue medication after a private ADHD diagnosis? covers that conversation.

What every route in Ontario has in common: DSM-5-TR criteria and a childhood history

CADDRA's Canadian ADHD Practice Guidelines describe assessment and treatment without reserving diagnosis to one profession, and an Ontario clinician following them will take a structured history, use validated rating scales, seek collateral information where possible, and consider other explanations before concluding.

1. Gather childhood evidence: report cards, a parent's recollections, an IEP, or an early school assessment.
2. Note current medications and any diagnoses of anxiety, depression or sleep disorders, because the assessor needs to separate these from ADHD.
3. Choose a route by what you need afterwards: medication (physician or NP), a psychometric report for school (psychologist), therapy, or a combination.
4. Confirm the professional's registration on the CPSO, CNO or CPBAO public register before booking.

Finding Focus provides online ADHD assessment and treatment for adults and teens in Ontario: after a short online intake, you have one consultation with a licensed Canadian clinician by video, with no referral needed, from $399. The assessment follows DSM-5-TR criteria and can conclude that ADHD is not the explanation. If you need help right now, call or text 9-8-8, Canada's Suicide Crisis Helpline, or call 911.