Temporal variation in the incidence of treated psychotic disorders in young people

Abstract

The incidence of psychotic disorders varies between geographical areas, however less is known about whether it varies over time in the same region. Analyzing this temporal variation of incidence could improve the allocation of healthcare resources and our understanding of the aetiology of psychotic disorders. This study aimed to determine whether there was a change in the incidence of psychotic disorders over a six-year period. MethodsYoung people aged 15 to 24 presenting with a first episode of psychosis (FEP) attending an early intervention service in Melbourne between 2011 and 2016 were included. The population at-risk was determined from the two corresponding census periods and analyses were adjusted for age, sex and migrant status. ResultsA total of 1217 young people presented with a FEP over the six-year period and the crude incidence rate in 2011 was 102.4 per 100,000 population at-risk, compared to 125.4 in 2016.There was an increase in the incidence by 33% in 2015 (aIRR=1.33, 95% CI 1.09-1.63) and 28% in 2016 (aIRR=1.28, 95% CI 1.05-1.56). When examined according to diagnostic groups, there was an increase in the incidence of substance-induced psychotic disorders among females in 2015 (aIRR=4.62, 95% CI 1.02-20.8). DiscussionThis study shows significant temporal variations in the incidence of treated psychotic disorders. These findings demonstrate that early intervention services should continually monitor incidence case numbers and funding should be provided accordingly, to ensure the required intensive and comprehensive treatments can be sustained.

A public early intervention approach to first‐episode psychosis: Treated incidence over 7 years in the Emilia‐Romagna region

“…Our estimates are higher than those from the Bologna and the other Italian centres (Palermo and Veneto), as well as that of the region of Sicily (Mulè et al, 2017), but they are lower than those from South London and Amsterdam, urbanized areas with high prevalence of risk factors, especially migration and cannabis (Di Forti et al, 2019). Our estimates are also much lower if compared to a recent Australian estimate (102.4 per 100 000 population at‐risk) (Pignon et al, 2021). Finally, our estimates are similar to those of a recent meta‐analysis (Jongsma et al, 2019) which detected extreme levels of heterogeneity in the incidence of psychosis across countries, and also failed to detect time‐related trends.…”

The incidence and admission rate for first-episode psychosis in young people before and during the COVID-19 pandemic in Melbourne, Australia

“…Furthermore, the incidence of psychotic disorders is relatively low and therefore it would be unlikely to observe a large change in a short period of time, within one service. It also needs to be considered that the incidence of FEP is not temporally stable, as we have found increases of up to 33% in the incidence of FEP in this catchment area when comparing the incidence across different years (Pignon et al, 2021). Therefore, even if statistical differences had been observed, we could not have attributed them solely to the COVID-19 pandemic or the associated restrictions.…”