The prevalence of schizophrenia and other psychotic disorders among homeless people: a systematic review and meta-analysis

Abstract

BackgroundSchizophrenia and other psychotic disorders constitute a huge global burden of disease and they are major contributors to disability as well as premature mortality among homeless people. This systematic review and meta-analysis aimed to estimate the pooled prevalence of schizophrenia and other psychotic disorders among homeless people.MethodsPubMed, Embase, and Scopus were searched to identify pertinent studies. We used a fixed- or random-effect meta-analysis to pool data from the included studies depending on the anticipated heterogeneity. A predesigned search strategy, as well as inclusion and exclusion criteria, were used. We also performed subgroup and sensitivity analysis and Cochran’s Q- and the I2 test was employed to compute heterogeneity. Egger’s test and visual inspection of the symmetry in funnel plots were used to assess publication bias.ResultsThirty-one studies involving 51,925 homeless people were included in the final analysis. The meta-analysis showed a remarkably higher prevalence of psychosis [21.21% (95% CI:13.73, 31.29), I2 = 99.43%], schizophrenia [10.29% (95%, CI: 6.44, 16.02), I2 = 98.76%], schizophreniform disorder [2.48% (95% CI: 6.16, 28.11), I2 = 88.84%] schizoaffective disorder [3.53% (95% CI: 1.33, 9.05), I2 = 31.63%,] as well as psychotic disorders not otherwise specified [9% (95% CI: 6.92, 11.62), I2 = 33.38%] among homeless people. The prevalence estimate of psychosis was higher in developing (29.16%) as compared to developed (18.80%) countries. Similarly, the prevalence of schizophrenia was highest in developing (22.15%) than developed (8.83%) countries.ConclusionThis systematic review and meta-analysis revealed that schizophrenia and other psychotic disorders are highly prevalent among homeless people, indicating an urgent need for studies to help develop better mechanisms of prevention, detection as well as treatment of those disorders among homeless people.

Prevalence of mental disorders among people who are homeless: an umbrella review

“…The pooled prevalence of current suicidal ideation among homeless individuals was 17.83% (95% CI: 10.73-28.14) whereas the prevalence of lifetime suicidal ideation was 41.6% (95% CI: 28.55-55.95); the pooled prevalence rates of current and lifetime suicidal attempt were 9.16% (96% CI: 4.1-19.2) and 28.8% (95% CI: 21.66-37.18); no significant difference in the prevalence of lifetime suicidal attempts was found based on the quality of the studies (Ayano, Tesfaw, et al, 2019) Embase, PubMed, Scopus, and additional sources; timeframe was not specified 31; Metaanalysis Studies were conducted in the US (n = 12), Canada (n = 4), Germany (n = 3), two studies Sample size ranged from 33 to 29,143; demographics and recruitment strategy of individual studies were not specified The pooled prevalence of psychotic disorder in homeless people was 21.21% (95% CI: 13.73-31.29); pooled prevalence rates of schizophrenia, schizophreniform disorder, schizoaffective disorder, and psychotic disorder not otherwise specified (NOS) were each in Ethiopia, France, and Scotland; one study each in China, Spain, UK, Ireland, Japan, Serbia, and Australia 10.29% (95% CI: 6.44-16.02), 2.48% (95% CI: 0.16-28.11), 3.53% (95% CI: 1.33-9.05), and 9% (95% CI: 6.92-11.62), respectively. In sensitivity analyses, developing countries had higher prevalence than developed countries (29.16% compared to 18.8% for psychotic disorders, and 22.15% compared to 8.83% for schizophrenia), screening tools revealed higher prevalence than diagnostic instruments (32.19% compared to 17.42%); both for psychotic disorder and schizophrenia, the prevalence rates were higher for studies published on/after 2010 compared to studies published before 2010; no significant difference in prevalence rates was found for the quality of the studies (…”

“…At the end of this stage, we removed 826 citations due to non-compliance with our criteria and evaluated full texts of the remaining 22 citations. Seven articles were excluded at this stage, and we retained 15 articles in this review (Ayano, Tesfaw, & Shumet, 2019;Ayano, Tsegay, Abraha, & Yohannes, 2019;Bassuk, Richard, & Tsertsvadze, 2015;Burra, Stergiopoulos, & Rourke, 2009;Depp, Vella, Orff, & Twamley, 2015;Duke & Searby, 2019;Embleton, Mwangi, Vreeman, Ayuku, & Braitstein, 2013;Ennis, Roy, & Topolovec-Vranic, 2015;Fazel, Khosla, Doll, & Geddes, 2008;Folsom & Jeste, 2002;Hodgson, Shelton, van den Bree, & Los, 2013;Parks, Stevens, & Spence, 2007;Schreiter et al, 2017;Smartt et al, 2019;Spence, Stevens, & Parks, 2004). The included articles consisted of seven meta-analytic reviews (Ayano, Tesfaw, et al, 2019;Ayano, Tsegay, et al, 2019;Bassuk et al, 2015;Depp et al, 2015;Embleton et al, 2013;Fazel et al, 2008;Schreiter et al, 2017), and eight non-quantitative reviews (Burra et al, 2009;Duke & Searby, 2019;Ennis et al, 2015;Folsom & Jeste, 2002;Hodgson et al, 2013;Parks et al, 2007;Smartt et al, 2019;Spence et al, 2004).…”

“…Among reviews without a contextual focus, most primary studies were in the US, Germany, Canada, UK, Australia, and other developed countries with fewer studies from LMICs (Ayano, Tesfaw, et al, 2019;Ayano, Tsegay, et al, 2019;Burra et al, 2009;Depp et al, 2015;Folsom & Jeste, 2002). Moreover, the earliest review was published in 2002, and a total of five reviews were published before 2010 (Burra et al, 2009;Fazel et al, 2008;Folsom & Jeste, 2002;Parks et al, 2007;Spence et al, 2004), whereas most (n = 10) reviews were published after 2010.…”

“…The number of primary studies included in the respective reviews ranged from 10 to 50. In addition, the evaluation of the methodological quality (please see Supplementary file) found seven reviews with medium quality (Embleton et al, 2013;Ennis et al, 2015;Folsom & Jeste, 2002;Hodgson et al, 2013;Parks et al, 2007;Schreiter et al, 2017;Spence et al, 2004) and eight reviews with high methodological quality (Ayano, Tesfaw, et al, 2019;Ayano, Tsegay, et al, 2019;Bassuk et al, 2015;Burra et al, 2009;Depp et al, 2015;Duke & Searby, 2019;Fazel et al, 2008;Smartt et al, 2019). The overall prevalence of schizophrenia ranged from 1% to 45%.…”

A meta-analysis of the association between RGS4 gene polymorphisms and schizophrenia

“…The systematic review and meta-analysis were conducted in adherence to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines [20]. A search was performed in English (PubMed, SZGene) and Chinese (CNKI, Wanfang and Weipu) databases with the following keywords: "the regulator of G-protein signaling 4" or "RGS4" and "schizophrenia".…”