The primary purpose of the present study was to examine the validity of commonly utilized ADHD rating scales within an adult forensic population. Participants were 120 patients assessed for dysfunctional anger and impulsive aggression at a hospital-based clinic. Two psychiatrists made independent diagnoses about the presence or absence of ADHD among individuals presenting with symptoms consistent with this disorder. Following the diagnoses, participants were assessed with multiple ADHD measures, including measures based on self-report, observer-report, or a computerized neuropsychological measure (IVA + Plus). With the exception of the IVA + Plus, the ADHD measures significantly differentiated individuals diagnosed with ADHD from individuals who were not so diagnosed. These measures also demonstrated good diagnostic utility via test specific parameters (sensitivity, specificity, positive predictive power, and negative predictive power). A sub-set of measures demonstrated particularly good classification accuracy, with high sensitivity (91 %) and good specificity (81 %). Implications of these findings for the effective assessment and diagnosis of ADHD in adult outpatient psychiatric settings are discussed.
