Preliminary support for the role of reward relevant effort and chronotype in the depression/insomnia comorbidity.

Background: The presence of insomnia in the context of depression is linked to a number of poor outcomes including reduced treatment response, increased likelihood of relapse, and greater functional impairment. Given the frequent co-occurrence of depression and insomnia, research into systems and processes relevant to both disorders, specifically reward processing and circadian rhythm disruption, may help parse this complex comorbidity.

Methods: A pilot study was conducted on a sample of 10 veterans with clinically significant depression and insomnia symptoms.