Social rhythm stability following late-life spousal bereavement: associations with depression and sleep impairment.

The aim of this study was to investigate changes in social rhythm stability and sleep in spousally bereaved subjects (n = 94) and in nonbereaved elderly control subjects (n = 45). Social rhythm stability and activity level were measured with a diary-like instrument, the Social Rhythm Metric (SRM). We observed that spousal bereavement, per se, was not associated with a lower social rhythm stability or activity level except in the presence of a major depressive episode. We also observed an inverse correlation between severity of depression and social rhythm stability, and a positive correlation between depression and both subjective and objective measures of sleep impairment. Higher social rhythm stability was correlated with better sleep in subjects with high activity levels, but not in subjects with low activity levels. Longitudinal data, including pre-bereavement assessment of social rhythm stability, are necessary to ascertain directional effects, i.e., whether loss of spouse occasions disruption of social rhythms or whether such disruption precedes sleep impairment and depression.