Gutwinski S, Schreiter S, Deutscher K, et al. - This systematic review and meta-analysis was performed on studies describing the prevalence of any mental disorder and major psychiatric diagnoses in clearly defined homeless populations in any high-income country.

• Researchers retrieved a sample of 39 studies including information from over 8,000 homeless individuals in 11 countries by conducting a systematic database search, extracting data from primary reports, and assessing their risk of bias.

• Random effects meta-analyses of 7 common diagnostic categories were performed.

• Homeless individuals had an increase in all prevalence estimates compared with general population estimates.

• The highest absolute rate, at 37%, was recorded for alcohol use disorders with substantially raised proportional excesses compared with the general population for schizophrenia spectrum disorders and drug use disorders as well.

• Prevalence estimates varied substantially between-studies, and as per meta-regression analyses, some of the heterogeneity is due to sampling method, participant gender distribution, and study country.