Social support and social strain in inter-episode bipolar disorder.

OBJECTIVES This study focused on social support and social strain and their cross-sectional associations with instabilities in sleep and social rhythms in inter-episode bipolar disorder (BD). METHODS Thirty-five adults diagnosed with inter-episode BD type I and 38 healthy controls completed measures of perceived social support and social strain. Group differences in support and strain were examined. Within the BD group, instabilities in sleep and social rhythms were assessed with 28 days of daily diary and actigraphy. Correlation and regression analyses were used to examine cross-sectional and prospective associations between social support, social strain, instabilities in sleep and social rhythms, and mood symptoms. RESULTS The BD group reported lower social support and higher social strain than the control group. Additionally, social strain was positively correlated with manic and depressive symptoms in the BD group. Furthermore, there was a cross-sectional association between social support and more stable sleep on actigraphy in the BD group, although social support did not predict future sleep instability. CONCLUSIONS These results indicate that inter-episode BD is associated with deficient social support and elevated social strain compared to controls, and that this may be due to persistent inter-episode mood symptoms. Social strain may be particularly important given its association with manic and depressive symptoms. The results also raise the possibility that sleep instability is related to poor social support in BD.