International incidence of psychotic disorders, 2002–17: a systematic review and meta-analysis

Abstract

Summary Background The last comprehensive systematic review of the incidence of psychotic disorders was published in 2004. New epidemiological data from different settings now permit a broader understanding of global variation. We examined the variation in psychosis by demographic characteristics and study method. Methods For this systematic review and meta-analysis, we searched PubMed, Embase, Web of Science, PsycINFO, and bibliographies, and directly contacted first authors. We sought to obtain citations of original research published between Jan 1, 2002, and Dec 31, 2017, on incidence of non-organic adult-onset psychotic disorder. We included papers that were published or in grey literature and had no language restrictions. Data were extracted from published reports, where possible, by sex, age, and ethnic group. Quality of yield was assessed. Data were assessed using univariable random-effects meta-analysis and meta-regression. We registered our systematic review on PROSPERO, number CRD42018086800. Findings From 56 721 records identified, 177 met inclusion criteria. The pooled incidence of all psychotic disorders was 26·6 per 100 000 person-years (95% CI 22·0–31·7). Heterogeneity was high ( I 2 ≥98·5%). Men were at higher risk of all psychotic disorders (incidence rate ratio 1·44 [1·27–1·62]) and non-affective disorders (1·60 [1·44–1·77]) than women, but not affective psychotic disorders (0·87 [0·75–1·00]). Ethnic minorities were also at excess risk of all psychotic disorders (1·75 [1·53–2·00]), including non-affective disorders (1·71 [1·40–2·09]). Meta-regression revealed that population registers reported higher rates of non-affective disorders (9·64 [2·72–31·82]), schizophrenia (2·51 [1·24–5·21]), and bipolar disorder (4·53 [2·41–8·51]) than first contact study designs. Interpretation We found marked variation in incidence of psychotic disorders by personal characteristics and place. Some geographical variation could be partially explained by differences in case ascertainment methods. Funding None.

Oral health treatment habits of people with schizophrenia in France: A retrospective cohort study

“…In accordance with a number of published studies, our PWS sample was predominantly male [51]. However, patients were more likely to be aged 35 to 64 even though the initial symptoms of schizophrenia often begin before 20 years of age [52].…”

Association of preceding psychosis risk states and non‐psychotic mental disorders with incidence of clinical psychosis in the general population: a prospective study in the NEMESIS‐2 cohort

“…The large and representative population cohort collected at four time‐points over 9 years was a major strength. The clinical psychosis outcome incidence and the point prevalence of psychosis high‐risk state were comparable to the population estimates in the literature 27,52 , thereby providing further support for the validity of our psychosis risk stratification approach in this population, that was guided by our previous work and verified using cumulative measures of environmental and genetic liability to schizophrenia. Nevertheless, future studies could benefit from a detailed clinical assessment and multi‐source data including electronic health records to minimize measurement bias.…”

Towards a public health approach to psychotic disorders

“…Studies that used large population registries or administrative health data tended to find a higher incidence of psychotic disorders than first contact studies that used standardised diagnostic procedures coupled with comprehensive case ascertainment strategies. 4 Many regions rely on these population-based datasets to inform public health strategies; although powerful, they often have insufficient standardisation across providers, institutions, and health-care systems. Conversely, first contact studies might represent a more rigorous epidemiological approach to obtaining data on the population distribution of psychotic disorders, but the intensity of resources required might render them unfeasible for ongoing population surveillance.…”

“…Studies that use consistent and standardised metrics are crucial for furthering understanding of the causes of psychotic disorders because differences across sites can provide important insights on key risk factors. 6 Also noteworthy in the findings from Jongsma and colleagues is the almost complete absence of estimates from low-income and middle-income countries, 4 which has also plagued larger-scale initiatives, such as the Global Burden of Disease study. 1,7 Given that the burden of mental disorders is rapidly increasing in these contexts as a result of the epidemiological transition from infectious diseases and malnutrition to more chronic conditions, psychotic disorders in these settings need to be better understood.…”

“…To advance a public health approach to psychotic disorders, a standardised metric for monitoring psychotic disorders is needed at the population level, as was so clearly highlighted by the heterogeneous data presented by Jongsma and colleagues. 4 To borrow an example from the obesity field, public health gains were possible once obesity measurement was standardised through body-mass index. 8 Despite the limitations of this measure, it provides a consistent and standardised metric for population health surveillance.…”