Depresssion in narcolepsy and hypersommia.

The authors studied the occurrence of depression in 100 randomly selected patients with narcolepsy and in 30 patients with hypersomnia. In the isolated form of idiopathic narcolepsy (without signs of cataplexy, sleep paralysis or hypnagogic hallucinations) depression occurred 28.6 per cent of cases. In idiopathic narcolepsy with cataplexy or other symptoms of sleep dissociation, depression was found in 17.2 per cent of cases. In idiopathic hypersomnia the occurrence of depression was 26.1 per cent. In the majority of cases the endogenous form of depression was observed. In the symptomatic form of narcolepsy and hypersomnia the occurence of depression has not been noted in any case. In most cases a parallel clincial course has been observed between the manifestation of depression and narcolepsy or hypersomnia. During a remission of the depressive state the hypersomniac symptoms decreased or disappeared totally. The authors furter discuss the possible pathophysiological mechanisms of the above mentioned symptoms. They are of the opinion that an important role is played by the secretion and metabolism of the cerebral monamines.