Authors:
Samuel Swidzinski | King's College London, Institute of Psychiatry | United Kingdom
Dr Sameer Jauhar | King's College London, Institute of Psychiatry
Prof. Dr. Robin Murray | King's College London, Institute of Psychiatry
Prof. Allan H Young | King's College London, Institute of Psychiatry
Dr Roxanna Short | King's College London, Institute of Psychiatry
Dr. Ben Carter | King's College London, Institute of Psychiatry
Annamaria Bari | King's College London, Institute of Psychiatry
Prof. Dr. Aswin Ratheesh | Orygen - Centre for youth mental health | The University of Melbourne
Dr. Diego Quattrone | King's College London, Institute of Psychiatry
Prof Paul Fearon | Trinity College Institute of Neuroscience School of Psychology and Department of Psychiatry at the School of Medicine Trinity College Dublin
Moxun Zheng | Kings College London | United Kingdom
Abstract
Background
Literature to date on the epidemiology of first-episode psychosis (FEP) has focused on non-affective psychoses, neglecting affective psychoses and schizoaffective disorder. We therefore sought to synthesise literature on a) their relative prevalence in the FEP samples and b) their crude incidence as discrete disorders, further examining moderating effects of urbanicity, population income level and geographical location.
Methods
We searched Embase, Medline, PsychInfo, and Global Health to extract data on the proportion (from prevalence studies) and crude incidence of individuals with an affective psychosis or schizoaffective disorder in FEP. No time restriction was specified. Observational studies were included. Outcomes were proportion and incidence of affective or schizoaffective psychosis in FEP. A dichotomous random-effects model was used.
Outcomes
We identified 44 samples (22 173 FEP participants) eligible for meta-analysis. The mean proportion of affective psychosis within FEP samples was 21·2% (95% CI 18·3-24·1). Proportion was higher in South America 32·8% (95%CI 29·3-36·4, p < 0·001). Proportion of schizoaffective disorder was 7·3% (95% CI 5·6-9·1). Heterogeneity was high for proportion of affective psychosis (I2 = 94·8%) and schizoaffective disorder (I2 = 95·1%).
Mean total crude incidence of FEP was 27·9/100 000 persons/year (95%CI 21·4-34·4). Mean incidence of affective psychosis and non-affective psychosis were 7·0/100 000 persons/year (95%CI 4·7-9·3) and 17·8/ 100 000 persons/year (95%CI 11·1-24·6) respectively. Heterogeneity was high for incidence of affective psychosis (I2 = 98·5%).
Interpretation
Given the incidence and relatively high proportion of affective psychosis within FEP, more attention should focus on this group and its optimal treatment.