This study followed 288 boys diagnosed with ADHD at ages 5 to 12 at a Pittsburgh clinic. Some had ADHD only (47 boys). Some also had oppositional defiant disorder, or ODD (135 boys). Some also had conduct disorder, or CD (106 boys). They were compared with 209 similar boys without ADHD. Years later, the boys and their parents reported delinquent acts done before age 18.
Boys with ADHD and CD did worst on almost every measure. Those who offended started younger than offenders in the other ADHD groups. They also committed a wider range of acts than any other group. Nearly half of them (45.3%) committed a severe offense. Mild offending was common and did not differ between groups. Boys with ADHD only or ADHD and ODD also started earlier and did more kinds of acts than boys without ADHD. Severe offending was higher than in comparison boys for the ODD group (25.4%) but not clearly so for the ADHD-only group (23.4%). Some gaps in severe offending between ADHD groups could be down to chance.
All the boys were clinic-referred and largely middle-class, and were diagnosed only once. The authors suggest that boys with ADHD may need treatment that starts early in childhood and lasts into the teen years, and that working with boys who have ADHD and ODD may help prevent the severe offending seen with CD.
The numbers Stats and what the terms mean
The statistics behind the plain-language claims above.
- Sibley, 2010: odds of severe delinquency, ADHD+CD versus comparison boys, OR=4.13, p<0.01.
- Sibley, 2010: odds of severe delinquency, ADHD+ODD versus comparison boys, OR=2.01, p=0.01.
- Sibley, 2010: odds of severe delinquency, ADHD-only versus comparison boys, OR=1.84, p=0.12.
- Sibley, 2010: odds of severe delinquency, ADHD+CD versus ADHD-only, OR=2.57, p=0.07 (did not reach the pre-set cutoff of 0.02).
- Sibley, 2010: odds of severe delinquency, ADHD-only versus ADHD+ODD, OR=1.63, p=0.36.
- Sibley, 2010: odds of severe delinquency, ADHD+ODD versus ADHD+CD, OR=1.58, p=0.22.
- Sibley, 2010: whether mild delinquency differed across the four groups, p=0.59.
- Sibley, 2010: estimated mean age of starting mild offending among mild offenders, 11.42 (ADHD-only, SE=0.21), 10.96 (ADHD+ODD, SE=0.12) and 10.36 (ADHD+CD, SE=0.14) versus 12.46 (comparison, SE=0.10), all p<0.01.
- Sibley, 2010: estimated mean age of starting moderate offending among moderate offenders, 13.36 (ADHD-only, SE=0.24), 13.43 (ADHD+ODD, SE=0.14) and 11.99 (ADHD+CD, SE=0.14) versus 14.50 (comparison, SE=0.12), all p<0.01.
- Sibley, 2010: number of different delinquent act types out of 34, 6.19 (ADHD-only), 6.72 (ADHD+ODD) and 8.69 (ADHD+CD) versus 5.37 (comparison), all p<0.01. What the terms mean:
- OR (odds ratio) compares how likely one group was to do something with another group; 1 means no difference and higher means more likely.
- p is how likely a gap this size would be if there were really no difference; smaller means less likely to be down to chance.
- SE (standard error) shows how precise an estimate is; smaller means more precise.
Source: Sibley M, Pelham W, Molina B, et al.. The Delinquency Outcomes of Boys with ADHD with and Without Comorbidity. Journal of Abnormal Child Psychology (2010). doi:10.1007/s10802-010-9443-9