The results of a new study published in JAMA Psychiatry suggest that, with an average lifetime prevalence of ever having an episode at 5.8%, psychotic experiences in the general population are infrequent.
Because of concerns over psychotic experiences being reported by a sizable minority of people, research is now focusing more closely on determining the true extent people experience hallucinations and delusions within the population.
One recent meta-analysis of 61 studies suggested that the median lifetime prevalence of psychotic episodes is 7.2% – substantially higher than the lifetime morbid risk for psychotic disorders, such as schizophrenia, which has a reported prevalence of 0.7%.
Previous studies have suggested that psychotic episodes predict a variety of mental disorders, such as mood, substance abuse and psychotic disorders, as well as anxiety, schizophrenia and full psychosis.
Data from the World Health Organization World Mental Health surveys – drawn from 18 countries across North and South America, Africa, the Middle East, Asia, the South Pacific and Europe – were analyzed by researchers from the University of Queensland in Australia.
The researchers found that 5.8% of the 31,261 adult respondents reported having had a psychotic experience at some point in their lives.
Breaking the psychotic experience down to its component halves, the results also show that the lifetime prevalence of hallucinatory experiences among the participants was 5.2%, and 1.3% for delusional experiences.
Women were found to be more likely to have psychotic experiences than men, with a lifetime prevalence of 6.6% compared with 5%. Individuals in middle-income countries were also more likely to have psychotic episodes, with a lifetime prevalence of 7.2%, compared with high-income countries (6.8%) and low-income countries (1.3%).
In the conclusion to their study, the researchers write:
“We have provided, to our knowledge, the most comprehensive description of the epidemiologic landscape of psychotic experiences (PEs) published to date. Although the lifetime prevalence of PEs is 5.8%, these events are typically rare. […] The research community needs to leverage this fine-grained information to better determine how PEs reflect risk status. Our study highlights the subtle and variegated nature of the epidemiologic features of PEs and provides a solid foundation on which to explore the bidirectional relationship between PEs and mental health disorders.”
The authors add that one strength of their study is that, as the survey data analyzed was cross-national, they were able to identify risk factors that exist consistently across countries, despite cultural factors specific to individual regions.
One example of a finding that was consistent across nations was that unmarried or unemployed people had a significantly higher prevalence of hallucinatory and delusional experiences. However, prevalence of hallucinatory experiences varies in comparison to delusional experiences across certain demographics – for instance, women have a higher prevalence of hallucinations than delusions.
Another unexpected demographic-specific variation in prevalence was that migrants in the study were significantly less likely to report hallucinatory experiences compared with native-born respondents.
Earlier this month, Medical News Today reported on a Canadian study published in CMAJ that found immigrants from the Caribbean and refugees from East Africa and South Asia are twice as likely to develop psychotic disorders in comparison with the general population.