Khat-induced hypnagogic hallucinations.

Khat is a plant whose leaves are chewed for their stimulating effect. This effect is attributed to cathinone, an alkaloid identical to dextroamphetamine. Khat chewing is widespread among eastern African and Yemenite populations and is believed to be innocuous. Our experience shows, however, that a substantial number of chronic khat chewers experience persistent hypnagogic hallucinations - a symptom that has not yet been described. Three vignettes illustrates this phenomena, which often interferes with psychiatric diagnosis. Different explanatory models are discussed, among them chronic suppression of REM sleep.