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

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 I 2 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.