Khat (Catha edulis): A systematic review of evidence and literature pertaining to its harms to UK users and society

Abstract

The use of khat (Catha edulis) has been associated with a large number of physiological and societal harms, leading to calls for it to be controlled in the UK. The evidence of these harms is often equivocal, limited by confounding factors, or entirely anecdotal: high-powered, quality-controlled studies are lacking. Regardless, the body of relevant literature indicates that the once socially-regulated use of khat has been eroded. Some individuals have developed excessive consumption patterns, either using khat daily or in binge-sessions, though daily consumption is not necessarily problematic per se. The majority of users seem to use khat in moderation, where the associated harms appear low. For excessive users, harms associated with khat are greater, particularly relating to mental health. Social harms also seem to be largely related to excessive khat use rather than khat use itself. Even in cases of excessive khat use, however, causal relationships between chewing and harms have not been described. More research is required to establish the role of khat in liver disease, coronary problems, cancers of the digestive tract and incidents of domestic violence. Studies should consider the likeliness that certain users are more vulnerable to developing patterns of excessive khat use due to an interwoven set of factors such as social health determinants and pre-and post-migration experiences.

Khat use and appetite: An overview and comparison of amphetamine, khat and cathinone

“…Additionally, research is needed examining the purity of the khat product due to contaminants at export when considering behavioral, chemical, and neurophysiological effects on appetite and metabolism. The relatively less severe withdrawal symptoms of khat (Thomas and Williams, 2013) may also affect free feeding behavior in the positive direction (potentially less prolonged anorexia), which may account for the inconsistent correlations between khat use and BMI.…”

A Pilot Community-Based Study on Association of Khat (Catha edulis) Chewing Practice with Psychosis in Yemen

“…The reported data about the prevalence of this habit in Yemen give an indication that at least 90 % of men are khat users [7,8]. Along with prevalent of this habit, almost among all Yemeni families, a lot of the literature confirms its negative impacts on the users, their families, and society [3]; for a review see [9,1]. In 1973, the WHO Expert with Psychosis in Yemen Committee on Drug Dependence has listed khat and recommended studying its psychoactive substances [10].…”

“…A psychoactive cathinone, structurally and functionally similar to D-amphetamine, was isolated from C. edulis [11]. Numerous studies on the topic of khat induced psychotic and schizophrenia-type disorders were systematically reviewed [12,13,9]; the majority of the related studies were case reports which could not reflect the risk factors of psychosis based on the population. Hence, the present study aims at evaluation of its association with stress, sleep disturbances, and anorexia among Yemeni people who are suffering chronic social and economic stressors.…”

Definition and Validity of the Construct “Problematic Khat Use”: A Systematic Review

“…Khat users reported increased functioning and socialization, believed to be beneficial, and relationship problems between children and parents, and serious financial problems, as negative consequences [8,15].…”

“…Although khat is one of the oldest psychoactive substances used by humans, little is known about which khat use pattern would lead to the above negative consequences. There are scoping and critical reviews on khat use and associated harms [8,26], but there is a dearth of evidence on the definition and indicators of problematic khat use.…”