SNAP-IV 26-Item Parent Rating Scale (SNAP)

Clinical intent

The SNAP-IV 26-item scale is an abbreviated version of the Swanson, Nolan, and Pelham (SNAP) Questionnaire (Swanson, 1992; Swanson et al., 1983). Items from the DSM-IV criteria for attention-deficit/hyperactivity disorder (ADHD) are included for the two subsets of symptoms: Inattention (items 1–9) and Hyperactivity/Impulsivity (items 10–18). Also, items from the DSM-IV criteria for oppositional defiant disorder (ODD) are included (items 19–26) because ODD is often present in children with ADHD. The scale can be used by the parents and teacher of children and adolescents between the ages of 8 to 18.

Calculation

This is calculated by assigning scores of 0, 1, 2, and 3 to the response categories, respectively, of “Not at all”, “Just a little”, “Quite a bit”, and “Very much”. SNAP is divided into three Subsets: Questions 1 – 9: Inattention Subset Questions 10 – 18: Hyperactivity/Impulsivity Subset Questions 19 – 26: Opposition/Defiance Subset

The scores in each of the three subsets (inattention, hyperactivity/impulsivity, and opposition/defiance) are totalled.

Clinical interpretation

Questions 1 – 9: Inattention Subset < 13 = Symptoms not clinically significant 13 – 17 = Mild symptoms 18 – 22 = Moderate symptoms 23 – 27 = Severe symptoms

Questions 10 – 18: Hyperactivity/Impulsivity Subset <13 = Symptoms not clinically significant 13 – 17 = Mild symptoms 18 – 22 = Moderate symptoms 23 – 27 = Severe symptoms

Questions 19 – 26: Opposition/Defiance Subset < 8 = Symptoms not clinically significant 8 – 13 = Mild symptoms 14 – 18 = Moderate symptoms 19 – 24 = Severe symptoms

Suggested Targets: <13/27 for inattention <13/27 for hyperactivity/impulsivity <8/24 for oppositional defiant disorder

If desired, the average rating for each subset can be calculated by totalling the scores for the items in the subset and dividing by the number of items. The average can be compared with cut-off scores suggestive of ADHD reported in the literature.

References

[1] https://pubmed.ncbi.nlm.nih.gov/18310593/ [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3623293/ [3] http://www.shared-care.ca/files/Scoring_for_SNAP_IV_Guide_26-item.pdf