Susan L. Smalley

Attention deficit hyperactivity disorder (ADHD) is a disorder characterized by attentional difficulties. Mindfulness is a receptive attention to present experience. Both ADHD and mindfulness are associated with attention and personality. This study tests whether individuals with ADHD have lower mindfulness scores than controls and, if true, whether personality contributes to these differences. One hundred and five adults (half with ADHD) were assessed for mindfulness, using the Kentucky Inventory of Mindfulness Skills, and personality, using the Tridimensional Character Inventory. Individuals with ADHD report themselves as less mindful than non‐ADHD controls and more novelty‐seeking, less self‐directed, and more self‐transcendent. Mindfulness is negatively associated with ADHD and positively associated with self‐directedness and self‐transcendence. Analyses of subscales of mindfulness suggest that ADHD is associated most with the “Acting in Awareness” dimension, perhaps because of shared items reflecting attentional variability. The current findings support that a large portion of variability in trait mindfulness can be explained by ADHD status and personality traits of self‐directedness and self‐transcendence. It further suggests that interventions that increase mindfulness might improve symptoms of ADHD and increase self‐directedness and/or self‐transcendence. © 2009 Wiley Periodicals, Inc. J Clin Psychol 65: 1–12, 2009.

Although social difficulties are a common feature of Attention-Deficit Hyperactivity Disorder (ADHD), little is known about the diversity of social problems, their etiology, or their relationship to disorders of social behavior, such as autism or Pervasive Developmental Disorder (PDD). In 379 children and adolescents with ADHD, social functioning was assessed using the Child Behavior Checklist (Achenbach, 1991). Factor analysis and structural equation modeling revealed two factors that we labeled Peer Rejection and Social Immaturity. A factor reflecting `PDD risk' was defined from eight items of a separate screening instrument for PDD and examined for its association with these two social factors. There was a significant association with both factors, but the association was much stronger for the Social Immaturity (Standardized Beta [β ] = .51) than Peer Rejection (β = .29) factors. Social Immaturity was also associated with a greater number of hyperactive symptoms while high Peer Rejection was associated with increased aggression and lower IQ in the ADHD children.

Attention deficit hyperactivity disorder (ADHD) is a highly heritable disorder affecting some 5–10% of children and 4–5% of adults. The cannabinoid receptor gene (CNR1) is a positional candidate gene due to its location near an identified ADHD linkage peak on chromosome 6, its role in stress and dopamine regulation, its association with other psychiatric disorders that co‐occur with ADHD, and its function in learning and memory. We tested SNP variants at the CNR1 gene in two independent samples—an unselected adolescent sample from Northern Finland, and a family‐based sample of trios (an ADHD child and their parents). In addition to using the trios for association study, the parents (with and without ADHD) were used as an additional case/control sample of adults for association tests. ADHD and its co‐morbid psychiatric disorders were examined. A significant association was detected for a SNP haplotype (C‐G) with ADHD (P = 0.008). A sex by genotype interaction was observed as well with this haplotype posing a greater risk in males than females. An association of an alternative SNP haplotype in this gene was found for post‐traumatic stress disorder (PTSD) (P = 0.04 for C‐A, and P = 0.01 for C‐G). These observations require replication, however, they suggest that the CNR1 gene may be a risk factor for ADHD and possibly PTSD, and that this gene warrants further investigation for a role in neuropsychiatric disorders.