Later ("evening") circadian preference is associated with poorer executive, academic, and attentional functioning in adolescents with and without ADHD.

This study provides compelling evidence that poorer academic, executive, and attentional functioning are more closely associated with greater eveningness than with sleep duration or quality in adolescents. Findings suggest that targeting circadian preference may be important to reduce these problems in adolescents, especially in clinical samples such as ADHD for whom academic, executive, and attentional difficulties are exceptionally common.