The relationship between sleep disturbance and depression

This paper focuses on several aspects of the relationship between sleep and depression, with particular attention to objective factors and subjective perceptions. It does not address the effect that antidepressants have on sleep, nor does it explore the wider implications of the types and course of depression, age, or other psychiatric conditions. “Normal sleep” is explored, examining typical sleep architecture in individuals without sleep disorders, psychiatric conditions or physical illness. Sleep disorders are reviewed and examined to present the nature of the disturbance and the role that they may play in depression, with particular attention paid to insomnia. Studies have identified a sub-group of insomnia patients (highly distressed poor sleepers), who appear to be less satisfied with their sleep quality than “low distressed poor sleepers”, even though they did not differ on sleep timing perceptions. Recent work has shown that depressed individuals to be less satisfied with sleep quality than healthy controls, even though they did not differ on sleep timing perceptions. The evidence presented here supports the view that subjective sleep perceptions play an important role in depression. Poor subjective perceptions of sleep in depression may be associated with faulty cognitions. This has been found extensively in insomnia, but is under-researched in depression.