Relationships Among Sleep Disturbance, Reward System Functioning, Anhedonia, and Depressive Symptoms

Abstract

Recent models propose reward system dysfunction as a key mediator of the relationship between sleep and depression and anhedonia. This study explored interrelationships among sleep disturbance, depressive symptoms, anhedonia, and reward responsiveness. Two-hundred and sixty undergraduate students completed questionnaires and a daily diary paradigm assessing sleep, reward responsiveness, depression, anhedonia, and positive affect over 1 week. Baseline sleep disturbance was associated with depressive symptoms, anhedonia, and reward responsiveness. Daily diary sleep parameters showed differential associations with anticipatory versus consummatory reward responsiveness and positive affect. Poorer sleep quality, shorter sleep duration, and longer awakening after sleep onset predicted blunted anticipatory and consummatory reward responsiveness, while increased sleep onset latency and lower sleep efficiency predicted only decreased consummatory reward responsiveness. All sleep indices, except sleep onset latency, were associated with positive affect. Findings demonstrate unique associations between disparate sleep disturbance and reward responsiveness elements, highlighting new treatment mechanisms for anhedonia and depression.

Keywords: anhedonia; depression; reward processing; sleep.