Khat chewing as a cause of psychosis.

It is well established that psychosis may arise in the context of abuse of certain illicit drugs (e.g. amphetamine). This article reviews the effects of chewing the plant khat and outlines the pharmacological aspects, the dependence issue and a comparative study between previously reported cases and four cases reported here to highlight the epidemiology, clinical features and prognosis of khat-induced psychosis.