Adult self-ratings of the DSM-IV-TR symptoms of attention-deficit/hyperactivity disorder: An item response theory perspective.

DSM-IV-TR based rating scales are among the most common measures of ADHD in adulthood; however, the psychometric properties of these scales are not well-documented. This study uses an IRT model to determine which symptoms (items) best discriminate between 193 self-referred college students with varying levels of inattention and hyperactivity/impulsivity. Furthermore, the study investigates the possibility of gender bias in item endorsement. The hyperactive/impulsive items were significantly more reliable than the inattention items at identifying participants with Average and Above Average levels of the overall trait. Most items of both subscales exhibited a need for response format modification. Two items demonstrated significant gender bias. The results indicate a need for further investigation into the psychometric properties of the DSM-IV-TR symptoms of Inattention; whereas, the symptoms of Hyperactivity/Impulsivity appear to function appropriately. Keywords: Adult Attention Deficit/Hyperactivity Disorder, ADHD self-report ratings, Item Response Theory, ADHD diagnosis, Graded Response Model, Differential Item Functioning