Psychotic Experiences in the General Population
Authors: John J. McGrath, Sukanta Saha, Ali Al-Hamzawi, Jordi Alonso, Evelyn J. Bromet, Ronny Bruffaerts, José Miguel Caldas-de-Almeida, Wai Tat Chiu, Peter de Jonge, John Fayyad, Silvia Florescu, Oye Gureje, Josep Maria Haro, Chiyi Hu, Viviane Kovess-Masfety, Jean Pierre Lepine, Carmen C. W. Lim, Maria Elena Medina Mora, Fernando Navarro-Mateu, Susana Ochoa, Nancy Sampson, Kate Scott, Maria Carmen Viana, Ronald C. Kessler
Journal: JAMA Psychiatry (2015)

<h3>Importance</h3> Community-based surveys find that many otherwise healthy individuals report histories of hallucinations and delusions. To date, most studies have focused on the overall lifetime prevalence of any of these psychotic experiences (PEs), which might mask important features related to the types and frequencies of PEs. <h3>Objective</h3> To explore detailed epidemiologic information about PEs in a large multinational sample. <h3>Design, Setting, and Participants</h3> We obtained data from the World Health Organization World Mental Health Surveys, a coordinated set of community epidemiologic surveys of the prevalence and correlates of mental disorders in representative household samples from 18 countries throughout the world, from 2001 through 2009. Respondents included 31 261 adults (18 years and older) who were asked about lifetime and 12-month prevalence and frequency of 6 types of PEs (2 hallucinatory experiences and 4 delusional experiences). We analyzed the data from March 2014 through January 2015. <h3>Main Outcomes and Measures</h3> Prevalence, frequency, and correlates of PEs. <h3>Results</h3> Mean lifetime prevalence (SE) of ever having a PE was 5.8% (0.2%), with hallucinatory experiences (5.2% [0.2%]) much more common than delusional experiences (1.3% [0.1%]). More than two-thirds (72.0%) of respondents with lifetime PEs reported experiencing only 1 type. Psychotic experiences were typically infrequent, with 32.2% of respondents with lifetime PEs reporting only 1 occurrence and 31.8% reporting only 2 to 5 occurrences. We found a significant relationship between having more than 1 type of PE and having more frequent PE episodes (Cochran-Armitage<i>z</i> = −10.0;<i>P</i> &lt; .001). Lifetime prevalence estimates (SEs) were significantly higher among respondents in middle- and high-income countries than among those in low-income countries (7.2% [0.4%], 6.8% [0.3%], and 3.2% [0.3%], respectively; χ<sup>2</sup><sub>2</sub>range, 7.1-58.2;<i>P</i> &lt; .001 for each) and among women than among men (6.6% [0.2%] vs 5.0% [0.3%]; χ<sup>2</sup><sub>1</sub> = 16.0;<i>P</i> &lt; .001). We found significant associations with lifetime prevalence of PEs in the multivariate model among nonmarried compared with married respondents (χ<sup>2</sup><sub>2</sub> = 23.2;<i>P</i> &lt; .001) and among respondents who were not employed (χ<sup>2</sup><sub>4</sub> = 10.6;<i>P</i> &lt; .001) and who had low family incomes (χ<sup>2</sup><sub>3</sub> = 16.9;<i>P</i> &lt; .001). <h3>Conclusions and Relevance</h3> The epidemiologic features of PEs are more nuanced than previously thought. Research is needed that focuses on similarities and differences in the predictors of the onset, course, and consequences of distinct PEs.