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Ann Marie T. Sullivan, M.D., Commissioner
Governor Andrew M. Cuomo

Scoring Instructions for the SNAP-IV-C Rating Scale

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The SNAP-IV Rating Scale is a revision of the Swanson, Nolan and Pelham (SNAP) Questionnaire (Swanson et al, 1983). The items from the DSM-IV (1994) criteria for Attention-Deficit/Hyperactivity Disorder (ADHD) are included for the two subsets of symptoms: inattention (items #1-#9) and hyperactivity/ impulsivity (items #11-#19). Also, items are included from the DSM-IV criteria for Oppositional Defiant Disorder (items #21-#28) since it often is present in children with ADHD. Items have been added to summarize the Inattention domain (#10) and the Hyperactivity/Impulsivity domain (#20) of ADHD. Two other items were added: an item from DSM-III-R (#29) that was not included in the DSM-IV list for ODD, and an item to summarize the ODD domain (#30).

In addition to the DSM-IV items for ADHD and ODD, the SNAP-IV contains items from the Conners Index Questionnaire (Conners, 1968) and the Iowa Conners Questionnaire (Loney and Milich, 1985). The IOWA was developed using divergent validity to separate items which measure inattention/overactivity (I/O — items #4, #8, #11, #31, #32) from those items which measure aggression/defiance (A/D — items #21, #23, #29, #34, #35). The Conners Index (items #4, #8, #11, #21, #32, #33, #36, #37, #38, #39) was developed by selecting the items which loaded highest on the multiple factors of the Conners Questionnaire, and thus represents a general index of childhood problems.

The SNAP-IV is based on a 0 to 3 rating scale: Not at All = 0, Just A Little = 1, Quite A Bit = 2, and Very Much = 3. Subscale scores on the SNAP-IV are calculated by summing the scores on the items in the subset and dividing by the number of items in the subset. The score for any subset is expressed as the Average Rating-Per-Item, as shown for ratings on the ADHD-Inattentive (ADHD-I) subset:

  Not At All Just A Little Quite A Bit Very Much Item Score  
1. Makes careless mistakes     X   2  
2. Can’t pay attention       X 3  
3. Doesn’t listen       X 3  
4. Fails to finish work     X   2  
5. Disorganized   X     1 ADHD-In Total = 18, Average = 18/9 = 2.0
6. Can’t concentrate       X 3  
7. Loses things   X     1  
8. Distractible       X 3  
9. Forgetful X       0  

A scoring template for the DSM-IV subtypes of ADHD (In and H/Im), for ODD; for the dimensions of the CLAM (I/O and A/D); and for the Conners Index are presented below:

  ADHD-In ADHD-H/Im ODD I/O A/D Conners Index
  # 1   #11   #21   # 4   #21   # 4  
  # 2   #12=   #22   # 8   #23   # 8  
  # 3   #13   #23   #11   #29   #11  
  # 4   #14   #24   #31   #34   #21  
  # 5   #15   #25   #32   #35   #32  
  # 6   #16   #26           #33  
  # 7   #17   #27           #36  
  # 8   #18   #28           #37  
  # 9   #19               #38  
                      #39  
Total In =   H/Im =   ODD =   I/O =   A/D =   CI =  
Average =   =   =   =   =   =  
C =                      
  =                      
    Teacher Parent
Tentative 5% Cutoffs: ADHD-In 2.56 1.78
  ADHD-H/Im 1.78 1.44
  ADHD-C 2.00 1.67
  ODD 1.38 1.88

The items on page 2 of the SNAP-IV Rating Scale are from other DSM-IV disorders which may overlap with or masquerade as symptoms of ADHD. In some cases, these may be comorbid disorders, but in other cases the presence of one or more of these disorders may be sufficient to exclude a diagnosis of ADHD. The SNAP-IV is not designed to be used in the formal process of diagnosing these non-ADHD disorders, but if symptoms on page 2 of the SNAP-IV receive a high (“Quite A Bit” or “Very Much”) rating, then an assessment of the implicated non-ADHD disorders may be warranted.

The DSM-IV Manual should be consulted to follow-up with an evaluation of these non-ADHD disorders. The DSM Codes and the page numbers in the DSM Manual are specified below to help in the assessment of possible conditions which may exclude or qualify a diagnosis of ADHD. A referral to a psychiatrist or a clinical psychologist may be required.

#41-#45 Conduct Disorder (DSM 312.8, p. 85)
#46 Intermittent Explosive Disorder (DSM 312.34, p. 609)
#47 Tourette’s Disorder (DSM 307.23, p. 103)
#48 Stereotypic Movement Disorder (DSM 307.3, p. 121)
#49-#50 Obsessive-Compulsive Disorder (DSM 300.3, p. 417)
#51-#56 Generalized Anxiety Disorder (DSM 300.02, p. 432)
#57 Narcolepsy (DSM 347, p. 562)
#58 Histrionic Personality Disorder (DSM 301.50, p. 655)
#59 Narcissistic Personality Disorder (DSM 301.81, p. 658)
#60 Borderline Personality Disorder (DSM 301.83, p. 650)
#61-#65 Manic Episode (DSM 296.00, p. 328)
#66-#73 Major Depressive Episode (DSM 296.2, p. 320)
#74-#76 Dysthymic Disorder (DSM 300.4, p. 345)
#77-#78 Posttraumatic Stress Disorder (DSM 309.81, p. 424)
#79-#80 Adjustment Disorder (DSM 309, p. 623)

Finally, the SNAP-IV includes the 10 items of the Swanson, Kotkin, Agler, Mylnn, and Pelham (SKAMP) Rating Scale. These items are classroom manifestations of inattention, hyperactivity, and impulsivity (i.e., getting started, staying on task, interactions with others, completing work, and shifting activi­ties). The SKAMP may be used to estimate severity of impairment in the classroom.

It is important to note that many disorders may produce impairment in the classroom setting, not just ADHD. Therefore, this rating scale is presented last to the possible exclusion conditions (on page 2 of the SNAP-IV) will be considered in addition to the inclusion criteria for ADHD (on page 1 of the SNAP-IV). Both should be considered before interpreting the SKAMP measure of classroom impairment or attributing high ratings on the SKAMP to ADHD.

  Academic Deportment
  #81   #87  
  #82   #88  
  #83   #89  
  #84   #90  
  #85      
  #86      
Total =   =  
Avg. =   =  
Orienting (#81,#86) =   Attention to Other (#87,#88) =  
Maintaining (#82,#83) =   Attention to Rules (#89,#90) =  
Directing (#84,#85) =