Sleeping Less Than Usual Is Associated With Greater Daily Depression and Higher Reactivity to Negative Interpersonal...

Changes in sleep can impact cognitive and emotional functioning and may contribute to depression. The current longitudinal study included a high-risk sample of adolescents and young adults with depression and/or suicidal thoughts and behaviors who were undergoing intensive outpatient treatment programs. We examined changes in sleep throughout treatment and whether daily changes in sleep impacted next-day depression through altered affective reactivity to interpersonal situations.

Participants (N = 198, ages 13-23, 82% White, 76% female sex at birth) were recruited from intensive treatment programs for depression and suicide risk. Participants wore an actigraph and completed daily ratings of depression, sleep, and positive and negative reactivity to interpersonal events throughout treatment (M = 60 days, SD = 22 days). Clinicians rated weekly depression severity. Multilevel models tested changes in sleep and depression throughout treatment and examined daily relationships between total sleep time (TST), next-day depression, and affective reactivity. Multilevel mediation tested whether increased affective reactivity mediated daily relationships between TST and depression.

Throughout treatment, self-reported TST increased (b = 0.01; p < .001) and daily self-reported depression severity decreased (b = -0.06; p = .02), although actigraphy-assessed TST did not change (b = 0.01; p = .16). Sleeping less than usual on diaries (b = -0.29; p = .02) but not actigraphy when controlling for covariates (b = -0.19; p = .18) was related to worse next-day depression. Greater clinician-rated depression severity amplified the effects of short TST on next-day depression for both diary (b = -0.22; p = .03) and actigraphy-assessed TST (b = -0.32; p = .01). Increased negative affectivity statistically mediated daily associations between short TST and increased next-day depression (indirect effects: B = 0.03; p < .001).

Short sleep may contribute to depression through increased negative affectivity to interpersonal events. Future work should test whether sleep interventions in high-risk samples hastens symptom improvement.