Daily Bidirectional Associations Between Sleep and Fatigue, Depression, and Anxiety in Stroke Survivors: A 7-Day Intensive Longitudinal Study

OBJECTIVE: To examine the bidirectional relationship between sleep quality and mood states including fatigue, depression, and anxiety in stroke survivors. DESIGN: A prospective observational study using ecological momentary assessment (EMA) surveys conducted 3 times daily over a 7-day period. SETTING: A tertiary-level, class A hospital. PARTICIPANTS: Thirty-four stroke survivors (N=34). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: EMA measures of mood symptoms (fatigue, depression, anxiety) and sleep, including subjective and objective total sleep time (TST), sleep onset latency (SOL), total wake after sleep onset (WASO), number of awakenings (NWK), sleep efficiency (SE), and sleep quality. RESULTS: Multilevel models revealed that more frequent NWK and increased TST were associated with greater fatigue, whereas higher SE was linked to lower depression levels. EMA analyses showed that greater daytime fatigue and evening anxiety were unexpectedly associated with improved same-night sleep quality, whereas better sleep quality was linked to increased next-day fatigue. No significant associations were found between sleep quality and next-day depression or anxiety. Fatigue and anxiety peaked in the morning and decreased significantly by evening, whereas depression showed reductions in the afternoon and evening compared with morning levels. However, no significant interaction was observed between sleep quality and time of day in their effects on mood. CONCLUSIONS: This study provides preliminary evidence of the intricate and dynamic relationship between sleep and mood in stroke survivors, highlighting the bidirectional associations and time of day effects. These findings emphasize the need for targeted, personalized, and multifaceted interventions to improve both sleep and mood in stroke patients. Further research is necessary to validate these observations and explore mechanisms underlying these associations.