Weiss Functional Impairment Rating Scale
Self Report (WFIRS-S)
Rate how your emotional or behavioural difficulties have affected each area of your life over the last month. This scale measures functional impairment, how ADHD affects what you can actually do, and is used clinically to track whether treatment is making a real-world difference.
This is not a diagnostic tool. The WFIRS-S measures how ADHD is affecting your life, not whether you have ADHD. Share your results with your clinician, they can use this to monitor progress and inform treatment decisions. No data is stored or sent anywhere.
About the WFIRS-S
The Weiss Functional Impairment Rating Scale, Self Report was developed by Dr Margaret Danielle Weiss, MD PhD. It is a validated instrument used by clinicians to assess the real-world impact of ADHD across seven domains of daily life, and to track how that impact changes with treatment.
Unlike symptom rating scales, the WFIRS-S measures what ADHD prevents you from doing, not just how often symptoms occur. NICE NG87, the national clinical guideline for ADHD, specifically recommends that clinicians use standard rating scales to record symptoms and functional impairment at baseline and at each stage of treatment (Recommendations 1.7.26 and 1.8.3). Completing this scale before a review appointment gives your clinician a structured picture of how ADHD is affecting your daily life in each domain.
How the WFIRS-S is scored
Each item is rated for the last month on a four-point scale: 0 (never or not at all), 1 (sometimes or somewhat), 2 (often or much) and 3 (very often or very much) — or N/A where a section does not apply. Items scored 2 or 3 highlight where difficulty is reported.
Scores are summarised for each of the seven domains as the number of items scored 2 or 3, the total score and the mean score. Using the CADDRA scoring guide, a domain suggests clinically significant impairment where the mean item score is 1.5 or higher, or two or more items score 2, or any item scores 3. A higher mean score in a domain indicates greater overall impairment in that area.
This tool is for information only and is not a diagnosis. Scores are calculated in your browser and are not stored or sent anywhere. Fill in the WFIRS-S below to see your own domain scores, then print or save them for your GP or clinician.
Your WFIRS-S results
Items scored 2 (Often) or 3 (Very often) highlight where difficulty is reported. Print or save as PDF to share with your GP or clinician.
| Domain | Items scored 2 or 3 | Total score | Mean score |
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How to use these results
- Using the CADDRA scoring guide, a domain suggests clinically significant impairment where the mean item score is 1.5 or higher, or two or more items score 2, or any item scores 3.
- A higher mean score in a domain indicates greater overall impairment in that area.
- If you are being treated for ADHD, repeat this scale regularly to track whether treatment is improving your functional outcomes. Bring results to your review appointments.
- Your clinician may use these scores to adjust your treatment. See our medications guide for information on ADHD treatment in Scotland.
- If you have not yet been assessed, see our NHS pathway or going private guides.
Copyright and permission
The WFIRS-S is copyright © Margaret Danielle Weiss, MD PhD. It is reproduced here with the express written permission of Dr Weiss, granted 25 June 2026. The scale may be used by clinicians and researchers free of charge. Contact Dr Weiss at margaret.weiss@icloud.com for permissions.
Clinical reference: Weiss MD. Weiss Functional Impairment Rating Scale, Self Report (WFIRS-S). University of British Columbia; 2000.
See also: NHS Scotland Right Decisions, ADHD clinical guidance · RCPsych CR235, ADHD in Adults: Good Practice Guidance (2023)