Inattentive symptoms of ADHD are related to evening orientation.

Objective: Morningness is a stable characteristic of individuals, related to impulsivity and novelty seeking. The evening orientation is a risk factor for psychiatric conditions such as depression and personality disorders. The authors hypothesized that adults suspected of having ADHD are more evening oriented than adults without ADHD. Method: Exploratory factor analyses were performed on the polychoric correlation matrices of the full Adult Self-Report Scale for ADHD (ASRS) and the Composite Scale of Morningness (CSM). Results: As expected, two factors for the ASRS-Inattention and Impulsivity Hyperactivity-and three factors for the CSM were retrieved. All three CSM factors correlated negatively with ASRS Inattention, none with ASRS Impulsivity-Hyperactivity. Conclusion: Inattention is more strongly related to eveningness than is Impulsivity-Hyperactivity, and therefore eveningness may constitute an endophenotype of the predominantly inattentive subtype of ADHD. These findings need to be replicated in a patient population with a standardized assessment of sleep quality. (J. of Att. Dis. 2009; 13(1) 36-41)