Worldwide Study Finds some People without Mental Illness Report “Psychotic” Experiences

Psychiatrists tend to assume that certain experiences are a clear sign of mental illness. These experiences include psychotic experiences such as hallucinations (hearing voices, seeing visions) and delusions (beliefs that are contrary to “consensual reality” for example the belief that one is being plotted against, or that thoughts are being removed from one’s brain, or one is being controlled by others…).

A new study published in JAMA Psychiatry shows that people who do not have a psychiatric disorder in the general population sometimes experiences these symptoms too.

This fits with the results of an earlier (1998) study of 15,000 Americans that found that 5% of people in the general population experienced hallucinations in a year. And of those, only half appeared to have a psychiatric condition.

In the current study, researchers from the University of Queensland in Australia and Harvard Medical School analyzed data from the World Health Organization World Mental Health Surveys that included more than 31,000 adults to assess the lifetime prevalence of psychotic experiences among the general population.

5.8 percent of those surveyed reported having at least one psychotic experience in their lifetime, with hallucinatory experience being the most prevalent at 5.2 percent compared with delusional experience at 1.3 percent. Psychotic experiences were more common among women (6.6 percent) than men (5 percent), and higher among individuals who lived in middle-income (7.2 percent) and high-income (6.8 percent) countries than those in low-income countries (3.2 percent).

Psychotic experiences were infrequent, with 32.2 percent of respondents with lifetime psychotic experiences reporting only one episode and 31.8 percent reporting having experienced two to five episodes.

These results point to the fact that unusual experiences are not necessarily a symptom of psychiatric disorders.

For more on psychosis in the general population, see the Psychiatric Services article “Treatment Seeking and Unmet Need for Care Among Persons Reporting Psychosis-Like Experiences.”

References

McGrath JJ, Saha S, Al-Hamzawi A, Alonso J, Bromet EJ, Bruffaerts R, Caldas-de-Almeida JM, Chiu WT, de Jonge P, Fayyad J, Florescu S, Gureje O, Haro JM, Hu C, Kovess-Masfety V, Lepine JP, Lim CCW, Mora MEM, Navarro-Mateu F, Ochoa S, Sampson N, Scott K, Viana MC, Kessler RC. Psychotic Experiences in the General PopulationA Cross-National Analysis Based on 31 261 Respondents From 18 Countries. JAMA Psychiatry.2015;72(7):697-705. doi:10.1001/jamapsychiatry.2015.0575

lHonig G et al. Auditory hallucinations: A comparison between patients and nonpatients. J Ncrv Ment Dis 1998; 186:646-51.