Dreaming away depression: the role of REM sleep and dreaming in affective disorders.

REM sleep and dreaming may play a crucial role in the processing of affect. In a recent study, we demonstrated that dream content is related to prevailing mood state and that certain types of dream precede upward mood changes in bipolar disorder (manic-depression). To replicate and extend initial findings, we monitored sleep, dream content and mood, in both bipolar and unipolar patients hospitalized for depression. All patients (n = 24) were recruited in a depressed state. During this trial, subjects reported their dreams and rated their mood each morning. They also had their sleep recorded intermittently using the Nightcap, a compact computerized home sleep monitoring device. We found that: (i) REM latency tends to increase as the mood improves in bipolars but is stable (and even decreases with mood improvements) in unipolar depressives; (ii) dream content continues to systematically relate to prevailing mood state, but the patterns seen are different in unipolars and bipolars; (iii) dreams of death are frequent in bipolar disorder and mark the transition of a mood shift upward.