SLEEP disturbance is often a feature of psychiatric syndromes which lead the patient to hospitalization. Knowledge of the characteristics of these sleep disturbances may aid in diagnosis and in estimating the prognosis of disorders such as depression. Muncie1 devised and used a "sleep chart" to record whether the subject was awake or asleep based upon observations made at half-hourly intervals throughout the night. In many hospitals, such a chart is a routine part of the patient's record. It is used by the clinician to corroborate the patient's history of sleep complaint during the initial stages of evaluation and, later, as a factor in assessing clinical course. Several studies on the role of sleep disturbance in depression using observed behavioral data have been published.2,3 The usefulness of the sleep chart in clinical practice and research studies can, however, be no better than the accuracy of the ratings made