1. The close similarity between the mental content of dreams and of psychoses has been reiterated. 2. Reference has been made to the narcolepsy-cataplexy syndrome and such related phenomena as sleep paralysis, somnambulism, and sleep hallucinosis, in which dissociation of the motor and the mental components of sleep occurs. 3. The concept is presented that the mental components of sleep, functioning as in dream content, may be similiarly dissociated in a more chronic form and be manifest as some of the bizarre mental content of psychoses. This concept is outlined in the accompanying table.