This study followed 300 children with Combined type ADHD from the Multimodal Treatment Study of Children with ADHD (MTA). They were aged 7.0 to 9.9 at the start. Peer rejection, and whether each child had a mutual friend, was measured 14 or 24 months later. Outcomes were checked 6 years after the start, at an average age of 14.9. A second check came at 8 years, at an average age of 16.8.
At 6 years, more rejected children showed more delinquency, smoking, anxiety and overall impairment. At 8 years, only the link with impairment remained. This held after accounting for study site, demographics, symptoms of ADHD, oppositional defiant disorder and conduct disorder, and each outcome's earlier level. The impairment link still held, and did not weaken, when a question about peer problems was removed from that measure.
Having a mutual friend predicted no later outcome and did not soften the effects of rejection. For smoking at 6 years, the result ran the other way: rejection predicted heavier smoking only among youth with a mutual friend.
The study covered only Combined type ADHD, and some children dropped out over time. Children without peer ratings were left out, so results may not apply to other ADHD types, racial minorities, girls or children in special education. It also had no data on autistic symptoms.
The numbers Stats and what the terms mean
The statistics behind the plain-language claims above.
- Mrug, 2012: how strongly peer rejection predicted overall impairment at 6 years, with the peer item removed, β =0.16.
- Mrug, 2012: how strongly peer rejection predicted overall impairment at 8 years, with the peer item removed, β =0.21.
- Mrug, 2012: how strongly peer rejection predicted amount smoked among youth with a mutual friend, β =0.27.
- Mrug, 2012: how strongly peer rejection predicted amount smoked among friendless youth, β =−0.01. What the terms mean:
- β A standardized measure of how strongly one thing predicts another once other factors are accounted for. Bigger numbers mean a stronger link, and a minus sign shows the direction, not the size.
Source: Mrug S, Molina B, Hoza B, et al.. Peer Rejection and Friendships in Children with Attention-Deficit/Hyperactivity Disorder: Contributions to Long-Term Outcomes. Journal of Abnormal Child Psychology (2012). doi:10.1007/s10802-012-9610-2