SNAP-IV vs Vanderbilt: Which Child ADHD Test Should You Choose?

If you're a parent trying to figure out whether your child's behavior might be ADHD, you'll quickly run into two names: SNAP-IV and the Vanderbilt ADHD Diagnostic Rating Scale. Both are clinically validated, both are in the public domain (so you can use them for free), and both are widely used by pediatricians in the United States. But they were designed for slightly different jobs — knowing which to pick saves you time and gives the clinician a better starting point.

You can take either of them right now on our free Child ADHD Test page — pick the assessment that matches your situation and get instant scoring. This guide explains how they differ so you can choose with confidence.

The Swanson, Nolan and Pelham Rating Scale (SNAP-IV, 26-item version) is a focused screener that covers the 18 DSM-5 ADHD symptoms (9 inattention + 9 hyperactivity-impulsivity) plus 8 oppositional defiant items. It uses a 0–3 frequency scale (Not at all / Just a little / Quite a bit / Very much) and is scored by averaging each subscale. Typical clinical cutoffs are an inattention average of about 1.78 and a hyperactivity-impulsivity average of about 1.44 for the parent version. SNAP-IV takes most parents three to four minutes to complete.

The NICHQ Vanderbilt Assessment Scale was developed in collaboration with the American Academy of Pediatrics and is the scale your pediatrician most likely hands you in the waiting room. The full parent form has 47 items: 18 DSM-5 ADHD symptoms, 8 oppositional defiant items, 14 conduct items, 7 anxiety/depression items, and 8 functional-impairment items covering school performance and relationships. Scoring is symptom-count based — six or more items rated "Often" or "Very Often" in either ADHD cluster, plus at least one impaired life area, meets the criteria for that presentation.

Length. SNAP-IV: 26 items, ~3 minutes. Vanderbilt Short (the 24-item version we offer): ~4 minutes. Vanderbilt Full: 47 items, ~8 minutes.

Symptom coverage. Both cover the 18 DSM-5 ADHD symptoms identically. SNAP-IV adds oppositional defiant. Vanderbilt Full adds oppositional, conduct, and anxiety/depression — important because roughly two-thirds of children with ADHD have at least one co-occurring condition.

Functional impairment. Vanderbilt explicitly asks about school performance, family relationships, peer relationships, and organized activities. A clinical diagnosis of ADHD requires impairment in at least one setting — Vanderbilt builds this in; SNAP-IV does not.

Scoring. SNAP-IV uses average scores against published cutoffs. Vanderbilt counts the number of items rated 2 or 3 (Often / Very Often). Vanderbilt's method is closer to how DSM-5 criteria are written.

Endorsements. The American Academy of Pediatrics' clinical practice guideline for ADHD recommends Vanderbilt-style instruments for primary-care evaluation. SNAP-IV is more common in research and in school-based screening.

Choose SNAP-IV if you only have a few minutes, you're looking for a quick first read, and you're not yet worried about co-occurring problems like anxiety or defiant behavior. It's also a good choice for tracking change over time once a diagnosis exists.

Choose the Vanderbilt Short (24 items) if you want a balanced general-purpose screen — all 18 DSM-5 symptoms plus the six most important functional-impairment items. This is what we recommend by default for most parents.

Choose the Vanderbilt Full (47 items) if you suspect more is going on — your child also has anxiety, depressive symptoms, frequent defiant behavior, or conduct problems. The extra eight minutes give your pediatrician a much richer picture and may save a follow-up visit.

Neither SNAP-IV nor Vanderbilt diagnoses ADHD on its own. Both are screening instruments. A formal diagnosis requires a clinician to combine parent ratings, teacher ratings (you can download the official NICHQ teacher Vanderbilt form for free), a developmental and medical history, and rule out conditions that can mimic ADHD — undiagnosed hearing or vision problems, sleep disorders, learning disabilities, anxiety, depression, or thyroid issues. Use the result of either scale as a structured data point to start that conversation with your pediatrician.

If you're at the very beginning of this process, our broader guide on how to get tested for ADHD walks through what a full evaluation looks like, and how doctors test for ADHD covers what each kind of provider actually does.

Ready to try one? Head to our free Child ADHD Test page. You'll choose your role (parent, teacher, or caregiver), pick one of the three assessments above, and get instant scoring with a subtype breakdown — all without an account or email. The result page also includes a link to download the official teacher form so you can complete the picture before your pediatrician visit.