Chronic khat use and psychotic disorders: A review of the literature and future prospects

Aims: In recent decades, the traditional habit of chewing the khat leaves, which contain the amphetamine-like cathinone, has undergone profound changes in African and Arab countries, from a socially regulated use pattern to uncontrolled consumption. This is of special public mental-health concern. In this article, a review of the scientific literature on the relationship between khat use and psychosis is provided. Results: Several case studies, but only a few group and community-based studies, have addressed this topic. The studies show inconsistent results, have methodological problems, and fail to report quantitative results. Many important questions remain unaddressed. Conclusions: The frequently stated association between khat use and psychosis contrasts with the small number of sound studies. Currently, only a few conclusions can be drawn, that excessive khat use can cause brief psychotic disorders and that people with a preexisting vulnerability should be discouraged to use it. The direction of causality between general psychopathology and khat use remains unclear. This review confirms the need for quantitative, controlled, and longitudinal studies, which can help deepen the understanding of the mental-health effects and its link to the development and course of long-lasting psychosis.