How Long Does an ADHD Assessment Take? — UK Guide 2025
Wondering how much time you need for an ADHD assessment? Here’s a clear guide on what happens, how long it takes, and what to expect both in NHS and private pathways.
NHS ADHD Assessment Timeline
Referral to Diagnosis:
Waitlist: 12–24+ months from GP referral to assessment
Screening forms: 1–2 months after referral
Diagnostic appointment: 1–2 hours
Follow-up: usually 3–6 months after diagnosis, depending on local resources
Total NHS timeline: 12–30 months, depending on your local area’s demand.
Private ADHD Assessment Timeline
Booking to Diagnosis:
Waitlist: 2–4 weeks (self-referral, no GP required)
Diagnostic appointment: 90–120 minutes
Report delivery: typically within 1–2 weeks of appointment
Medication initiation: same day or within 1 week if clinically appropriate
Total private timeline: 4–6 weeks from first enquiry to treatment plan.
What Happens in an ADHD Assessment?
✅ Structured clinical interview
✅ Review of developmental, educational, and mental health history
✅ ADHD-specific rating scales and symptom scoring
✅ Screening for coexisting conditions (e.g. anxiety, depression, sleep issues)
✅ Discussion of treatment options and next steps
Assessments are typically conducted via video or in-person by an ADHD nurse prescriber or psychiatrist.
Why Private ADHD Assessments Are Faster
Direct self-referral (no GP waitlist)
Flexible scheduling (evenings, weekends, remote)
Shorter booking queues
Dedicated ADHD-specialist clinicians
NHS capacity constraints and high demand are the main reasons for long NHS waiting times.
FAQs
Can I speed up an NHS ADHD assessment?
Only to a limited extent — some areas allow “right to choose” referrals, but wait times are still long.
Is a private ADHD assessment recognised by the NHS?
Yes, if done by a NICE-compliant provider with qualified clinicians.
Can I switch from private to NHS after diagnosis?
Yes — many people use private assessment to get started and then ask their GP for shared care.
