Relationship between objective and subjective sleep measures in depressed patients and healthy controls.

The purpose of this study was to correlate subjective sleep characteristics based on questionnaire response, and objective sleep EEG features based on polysomnography, in 52 patients with major depressive disorders (MDD) and 49 healthy controls. With the exception of the number of awakenings, subjective and objective sleep measures were strongly correlated in both groups. Patients and controls were able to accurately judge time in bed, total sleep time and sleep latency. However, sleep quality, depth, and how rested participants felt upon awakening were not strongly correlated with objective sleep characteristics, particularly in those with MDD. The findings suggest that estimates such as total sleep time and sleep latency, obtained from questionnaire data, bear a strong resemblance to objective polysomnographic characteristics in both those with MDD and healthy controls. Patients with MDD do not show sleep-state misperceptions although depressed women are more accurate in estimating sleep characteristics than depressed men.