The Impact of Sleep Disturbance on the Association Between Stressful Life Events and Depressive Symptoms

Abstract

Objectives: Sleep problems are common across the adult life span and may exacerbate depressive symptoms and the effect of common risk factors for depressive symptoms such as life stress. We examine sleep disturbance as a moderator of the association between stressful life events and depressive symptoms across five waves (25 years) of the nationally representative, longitudinal American Changing Lives Study.

Method: The sample includes 3,597 adults aged 25 years or older who were surveyed up to five times over 25 years. Multilevel models were run to examine between- and within-person variability in sleep disturbance and life event stress as predictors of depressive symptoms, and an interaction to test sleep disturbance as a moderator is included in a second step.

Results: Life events and sleep disturbance were associated with elevated depressive symptoms at the between- and within-person levels. A significant sleep disturbance by interaction of life events was found, indicating that when individuals experienced an above average number of life events and slept more restlessly than usual, they had a higher risk for depressive symptoms than individuals who experienced above average stress but slept well.

Discussion: Sleeping restfully may allow individuals the rejuvenation needed to manage stress adaptively and reduce depressive symptom burden.

Keywords: Depressive symptoms; Sleep disturbance; Stressful life events.

Figure 1.

Wave-specific variation in restless sleep as a significant moderator of the stressful life events and depressive symptoms association (wave-level interaction, γ₃₀). High and low restless sleep indicating 1 SD above and below the within-person level mean. Depressive symptoms are logged to adjust for skew. Life events are centered around the individual’s mean such that 0 indicates the mean, positive numbers indicate above average number of experienced events, and negative numbers indicate a below average number of experienced events.