Attention deficit hyperactivity disorder, combined type: better executive function performance with longer-term psychostimulant medication


  • Research, Evaluation and Practice Unit, Department of Psychological Medicine, Monash University, Level 2, 999 Nepean Highway, Moorabbin, Victoria Australia 3189. Email:

    Paul Maruff, Senior Research Fellow; Rebecca Barnett, PhD candidate

    Mental Health Research Institute of Victoria, Melbourne

Alasdair Vance, Senior Lecturer, (Correspondence)


Objective:  Executive function deficits are evident in primary school-age children with attention deficit hyperactivity disorder, combined type (ADHD-CT) and are possibly improved by longer-term psychostimulant medication. In contrast, a substantial subgroup of children with ADHD-CT become symptomatic despite longer-term psychostimulant medication use. We investigated the hypothesis that better executive function performance is associated with the use of longer-term psychostimulant medication in primary school-age children with ADHD-CT who are again symptomatic of ADHD-CT, despite its use.

Method:  A cross-sectional study of 40 primary school-age psychostimulant medication-naïve children with ADHD-CT, 26 with symptomatic ADHD-CT and treated with psychostimulant medication, and 26 control children without ADHD-CT was conducted. Nonverbal tasks of executive function were compared across the three groups.

Results:  The longer-term psychostimulant medication-treated group had a better executive function performance, despite being symptomatic for ADHD-CT, than the psychostimulant medication-naïve group.

Conclusion:  Improved executive function may be a marker of psychostimulant medication effect in children with ADHD-CT treated in the longer term. This improvement may not correlate with that of the ADHD-CT symptoms. Longitudinal studies are required.