Validated clinical tool · For parents and carers

Weiss Functional Impairment Rating Scale

Parent Report (WFIRS-P)

Rate how your child's emotional or behavioural difficulties have affected each area of their life over the last month. This scale is used clinically to measure functional impairment and to record functioning before and after treatment.

This is not a diagnostic tool. The WFIRS-P measures how your child's difficulties are affecting their life, not whether they have ADHD or autism. Share your results with your child's clinician, they can use this to monitor progress and inform treatment decisions. No data is stored or sent anywhere.

About the WFIRS-P

The Weiss Functional Impairment Rating Scale, Parent Report was developed by Dr Margaret Danielle Weiss, MD PhD. It is completed by a parent or primary carer, rating how their child's emotional and behavioural difficulties affect family life, school, daily skills, and social participation.

The WFIRS-P is used by clinicians to assess functional impairment and to monitor the effect of treatment over time. CADDRA notes that the scale has no items redundant with ADHD symptoms, so symptoms and functioning can be looked at as independent outcomes. NICE guideline NG87 says: "During the titration phase, ADHD symptoms, impairment and adverse effects should be recorded at baseline and at each dose change on standard scales by parents and teachers" (recommendation 1.7.26). Completing this before an appointment gives your child's clinician a structured picture across all key areas of their life. See our NHS autism pathway and NHS ADHD pathway for information on assessment in Scotland.

50questions

6domains

No data stored

How the WFIRS-P 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 six domains as the number of items scored 2 or 3, the total score and the mean score. The CADDRA instructions for the WFIRS say a domain is considered impaired if two items are rated 2 or one item is rated 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-P below to see your child's domain scores, then print or save them for CAMHS or your clinician.

Who should complete this? A parent, step-parent, foster carer, or other primary carer who lives with the child and can observe their day-to-day behaviour across settings. Rate based on your own observations, not what you think their teacher or others would say.

There is also a self-report version (WFIRS-S) for adults rating themselves.

Over the last month Your answers are completely private, nothing is saved or sent

WFIRS-P results

Items scored 2 (Often) or 3 (Very often) highlight where difficulty is reported. Print or save as PDF to share with your child's clinician.

Domain	Items scored 2 or 3	Total score	Mean score

How to use these results

The CADDRA instructions for the WFIRS say a domain is considered impaired if two items are rated 2 or one item is rated 3.
A higher mean score in a domain indicates greater overall difficulty in that area of your child's life.
If your child is being treated for ADHD, repeat this scale at each review to track whether treatment is improving functional outcomes. Bring results to appointments.
If your child is waiting for assessment, this can help you articulate to clinicians and to their school where the difficulties are having the greatest impact. Read our guide to the NHS autism pathway in Scotland or the NHS ADHD pathway.
If you are struggling while waiting, see our support resources or contact ADHD Scotland for advice.

Child's name (optional, appears on printed results)

Copyright and permission

The WFIRS-P 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, Dickson R, Wasdell M, et al. Weiss Functional Impairment Rating Scale, Parent Report (WFIRS-P). American Psychiatric Association 158th Annual Meeting, Atlanta, GA; 2005.

ADHD Scot is an independent, non-clinical information project. This tool does not provide a diagnosis and is not a substitute for clinical assessment. Always speak to your child's GP, paediatrician, or a qualified clinician about their health and treatment.