The Green Leaf: Khat Chewing and Mental Illness

Khat chewing is traditionally a habit in Yemen and some African countries such as Ethiopia, Somalia and Kenya, as well as among emigrants from these countries in different parts of the world. In the last few decades, there is rising concern among international health authorities that khat has harmful medical and mental effects related to excessive khat use. A relationship between khat use and mental illness has been suggested by clinical case reports and quantitative studies. This article provides literature reviews of clinical case reports and quantitative studies to the reported ‘mental illness of khat to chewers that presented in the international literature. This is a review partly based on a report of Warfa et al. 2007, WHO 1980, 2006, and Advisory Council on the Misuse of Drugs Dependence (ACMD) 2013. A literature search of a large number of medical databases, including via Google, Medline, PubMed, as well as the Internet was made to identify relevant reports up to 2023. Case report studies or literature do not clarify the confusion on khat effects, in addition to insufficient evidence between khat use and psychosis, the reports are contradictory, and inconclusive to attribute that khat use causes mental illness particularly psychosis.