Reduced sleep quality in healthy girls at risk for depression.

Depression is characterized by sleep difficulties, but the extent to which subjective and objective sleep disturbances precede depression are unclear. This study was designed to examine perceptions of sleep quality in addition to actigraphy- and diary-measured sleep variables in healthy girls at low and high familial risk for major depressive disorder. Forty-four healthy daughters and their mothers completed a week of daily sleep diary and actigraphy; 24 girls had mothers with no history of psychopathology (low risk, mean age 14.92 years), and 20 girls had mothers with recurrent depression during the daughter's lifetime (high risk, mean age 14.12 years). All daughters had no current or past psychopathology. High-risk girls reported significantly poorer subjective sleep quality than did low-risk girls (P = 0.001). The two groups of participants did not differ in actigraphy- or diary-measured sleep duration, onset latency or snooze duration. Healthy girls at high familial risk for depression report poorer sleep quality than do girls at low risk for depression, despite the absence of group differences in objective sleep disturbances as measured by actigraphy or daily diary. This pattern of findings may reflect a broader cognitive or physiological phenotype of risk for depression.