SNAP-IV Teacher and Parent Rating Scale
SNAP-IV Teacher and Parent Rating Scale overview
Creator and Context
The SNAP-IV is the fourth revision of the Swanson, Nolan and Pelham rating scale, revised by James Swanson at the University of California, Irvine, against DSM-IV criteria.
It was the primary outcome measure in the NIMH Multimodal Treatment Study of ADHD, which is why it remains a reference instrument in ADHD research and practice. It circulates in an 18 item ADHD only version, a 26 item version that adds oppositional defiant disorder, and a full 90 item version.
Presenting Conditions
The scoring template produces:
ADHD inattention (9 items)
ADHD hyperactivity and impulsivity (9 items)
ADHD combined (the 18 ADHD items)
Oppositional defiant disorder (8 items)
The 90 item version adds the IOWA Conners inattention and overactivity and aggression and defiance subscales, a Conners index, and the SKAMP classroom impairment items.
Administration
Self completed by a parent or a teacher. Items are rated Not At All (0), Just A Little (1), Quite A Bit (2) or Very Much (3). No explicit recall window is printed on the form.
Desired Audience
Parents and teachers of school aged children. The normative study used elementary school students, and the MTA sample was aged 7 to 9 at entry.
The SNAP-IV's strength is monitoring. Because it is scored as an average rating per item rather than a raw sum, it is easy to compare a child against themselves over time, which is exactly what titration and treatment review require.
Considerations
Not a diagnostic instrument.
The published cut offs are explicitly labelled tentative by the author and are rater specific. Parent and teacher scores are not interchangeable.
Item content is based on DSM-IV wording.
Multiple versions circulate with different item numbering. The hyperactivity block is items 11 to 19 in the 90 item version but 10 to 18 in the 26 item version. Any scoring engine must key off the specific version.
No recall window is stated on the form.
How to score the SNAP-IV Teacher and Parent Rating Scale
Conducting the assessment
The informant rates each item from Not At All (0) to Very Much (3). Subscale scores are calculated as the sum of the item scores divided by the number of items in that subscale, giving an average rating per item from 0 to 3.
Interpretation
Scores are expressed as an average rating per item, from 0 to 3.
Swanson's tentative 5 percent cut offs, which approximate the 95th percentile, differ by rater:
ADHD inattention: 2.56 teacher, 1.78 parent
ADHD hyperactivity and impulsivity: 1.78 teacher, 1.44 parent
ADHD combined: 2.00 teacher, 1.67 parent
Oppositional defiant disorder: 1.38 teacher, 1.88 parent
The author presents these as tentative rather than validated diagnostic thresholds.
Clinical Considerations
Use the correct rater specific cut off. A teacher inattention threshold of 2.56 against a parent threshold of 1.78 is a large difference, and mixing them up will misclassify children.
Track the average rating per item against the child's own baseline rather than against the cut offs when monitoring treatment.
Items on the wider version that flag non ADHD disorders are prompts to assess, not findings.
SNAP-IV Teacher and Parent Rating Scale use cases
Rating ADHD and oppositional symptoms across home and school
Monitoring response to treatment, including medication titration
Research, where it is one of the most widely used ADHD outcome measures
Category
ADHD
Research Summary
Swanson, J. M., Nolan, W., & Pelham, W. E. (1983). The SNAP rating scale for the diagnosis of attention deficit disorder. Psychopharmacology Bulletin.
Swanson, J. M., Kraemer, H. C., Hinshaw, S. P., et al. (2001). Clinical relevance of the primary findings of the MTA. Journal of the American Academy of Child and Adolescent Psychiatry, 40(2), 168 to 179.
Bussing, R., Fernandez, M., Harwood, M., Hou, W., Garvan, C. W., Eyberg, S. M., & Swanson, J. M. (2008). Parent and teacher SNAP-IV ratings of ADHD symptoms: Psychometric properties and normative ratings from a school district sample. Assessment, 15(3), 317 to 328.
Other Assessment Guides
Adult ADHD Self Report Scale ASRS v1.1
A guide to the WHO Adult ADHD Self Report Scale (ASRS v1.1). Covers the six question screener, both scoring methods including the updated 0 to 24 approach, and when to escalate to full assessment.
Vanderbilt ADHD Diagnostic Rating Scale VADRS
A guide to the Vanderbilt ADHD Diagnostic Rating Scale (VADRS), parent and teacher versions. Covers symptom and performance scoring, the DSM-5 aligned criteria and comorbidity screening.
Wender Utah Rating Scale WURS-25
A guide to the WURS-25, the retrospective self report of childhood ADHD symptoms in adults. Covers scoring, the difference between the 36 and 46 cut offs, and why it must be paired with a current symptom measure.
Note on Assessment licensing
Some assessments are copyright protected and require a licence or the copyright holder's permission for clinical, commercial or digital use. Where that applies, obtaining and maintaining that permission is the responsibility of the practice or organisation using the assessment. Tacklit provides the digital administration, scoring and reporting. We do not grant, transfer or supply rights to the underlying instrument.
