Exploring the association between khat use and psychiatric symptoms: a systematic review

Abstract

Objectives: Consumption of the drug khat is high across East Africa and the South-Western Arabian Peninsula despite evidence for its adverse psychiatric effects. This systematic review aims to explore cross-sectional research in the field to determine the strength of the association between khat use and psychiatric symptoms METHODS: Six databases were searched in October 2021-Ovid Medline, Embase, APA PsycINFO, CINAHL, Scopus and Proquest-using the following search terms: "khat" OR "qat" OR "qaad" OR "catha" OR "miraa" OR "mairungi" AND "depression" OR "anxiety" OR "mania" OR "psych*" OR "schiz*" OR "mental" OR "hallucinations" OR "delusions" OR "bipolar". Eligible studies were cross-sectional studies of any population or setting comparing the prevalence of psychiatric symptoms in long term or dependent khat users with non-users. The quality of each study was appraised by the Newcastle-Ottawa scale. A meta-analysis was planned using a random effects model to produce an OR with 95% CIs-using the Mantel-Haenszel method-alongside an I² statistic to represent heterogeneity. The quality of this meta-analysis was appraised using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) scoring system.

Results: 35 studies were eligible for inclusion (total participants=31 893), spanning 5 countries (Ethiopia, Somalia, Kenya, Saudi Arabia, UK). Meta-analysis suggests that khat use is associated with an 122% increased prevalence of psychiatric symptoms (OR 2.22, 95% CIs 1.76 to 2.79, p<0.00001, GRADE score: 'very low').

Conclusions: The high heterogeneity of the meta-analysis is likely due to the wide variation between the studies within the evidence base. To perform a more accurate systematic review, further primary studies are needed with standardised measurements of variables, particularly khat consumption.

Prospero registration number: CRD42020224510.

Keywords: adult psychiatry; mental health; psychiatry; public health; substance misuse.

Figure 1

PRISMA flow chart of included and excluded studies. PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Figure 2

Meta-analysis of included studies. M-H, Mantel-Haenszel.

Figure 3

Funnel plot of included studies.