ADHD prevalence in adult outpatients with nonpsychotic psychiatric illnesses

The prevalence of ADHD in the general adult population has been estimated to be about 4.4%. However, few studies exist in which the prevalence of ADHD in psychiatric adult outpatient samples has been estimated. These studies suggest that the prevalence is higher than in the general population. The objective of this study is to estimate the prevalence of ADHD in a psychiatric nonpsychotic adult outpatient sample and to compare this data with the prevalence of a group of nonclinical participants.

The structured clinical interview Mini International Neuropsychiatric Interview (M.I.N.I.-Plus) was applied to 161 consecutive nonpsychotic psychiatric adult outpatients and to 149 healthy participants from the community. In addition, clinical rating scales were applied to measure the severity of general psychopathology such as mania, anxiety, depression, ADHD, and alcohol consumption in both groups.

The prevalence of ADHD in psychiatric nonpsychotic adult outpatients was 16.80% and 5.37% in nonclinical participants. In male psychiatric outpatients the prevalence of ADHD was 8.5% and for females was 21.6%.

This study concludes that a higher prevalence of ADHD exists in psychiatric nonpsychotic adult outpatients compared with nonclinical participants. In the psychiatric adult outpatients, females showed a higher prevalence of ADHD than males. Implications and limitations are discussed.