Heterogeneity in the pharmacological treatment of children with ADHD: cognitive, behavioral, and social functioning differences.

OBJECTIVE To investigate the extent to which children with ADHD in various medication statuses (i.e., medication naïve, pure stimulant, stimulant plus another medication, nonstimulants) varied on cognitive or academic, behavioral, and social functioning during a psychoeducational assessment battery. METHOD Participants for this study consisted of 66 children (20 girls) with a Diagnostic and Statistical Manual of Mental Disorders (4th ed.) (DSM-IV) diagnosis of ADHD confirmed by a comprehensive clinical diagnostic assessment, including the use of a semistructured interview and Conners' Parent Rating Scales. Standardized cognitive and academic measures along with parent report of medication status, behavioral, and social functioning were collected. RESULTS No differences were found among children in the various medication groups in terms of ADHD symptoms severity, academic performance, processing speed, verbal abilities, or perceptual reasoning skills. However, children in the medication-naïve group performed significantly better than the stimulant-plus-another-medication and nonstimulant groups in terms of overall cognitive abilities, working-memory skills, and social adaptability but had similar scores to children in the pure-stimulant group. Children in the pure-stimulant group also had marginally higher working-memory scores compared to children in the nonstimulant group but not compared to the stimulant-plus-another-medication group. The pure-stimulant group also had significantly lower externalizing and internalizing problems and higher social adaptability compared to the stimulant-plus-another-medication group but not compared to the medication-naïve or nonstimulant groups. CONCLUSION Findings showed evidence for distinct cognitive, behavioral, and social profiles among children with ADHD who are proactively not on medication, as well as differences among children with ADHD who are on only one stimulant versus a nonstimulant or stimulant-plus-another-medication regimen.