Psychotic-like experiences: What are they and why are they important?

Dr Lorna Staines and Professor Mary Cannon of RCSI University of Medicine and Health Sciences, explore psychotic-like experiences, explaining what they are and why they are important

What are psychotic-like experiences?

It is widely thought that hallucinations and delusions occur only in the context of a psychotic disorder such as schizophrenia. Although this viewpoint is common, it is not accurate. Many people will have a hallucination or delusion throughout their lifetime even though they do not have a psychotic disorder. In most cases, they will happen for only a brief period before fading and only occur once.

Examples of such experiences might be hearing your name being called when alone in a house (auditory hallucination) or having an intensely strong feeling that someone on the street or in your neighbourhood may be trying to harm you, despite not having a reason to believe this (paranoid delusion). These are called “psychotic-like experiences” or “PLE”.

How common are psychotic-like experiences?

Psychotic-like experiences are reported in cross-sectional surveys by about one in 20 people overall in the population, with declining rates across ages. Young people are more likely to report PLE, with up to one in five stating that they have experienced a PLE at some time (Staines, Healy, Coughlan et al. 2021). For most people (70%) who report PLEs, they occur just once or very rarely (Staines, Healy, Murphy, et al., 2023). However, about 30% of people who report PLE will experience these more than once. – These are called recurrent or “persistent” PLEs. (Staines, Healy, Murphy, et al., 2023).

What are the consequences of a psychotic-like experience?

Having a PLE does not mean that a person has schizophrenia. However, people who experience PLE are at higher risk (about three times higher) to later become diagnosed with a mental health condition like anxiety disorder, depression, or substance use disorder (Healy et al., 2019). They also require greater healthcare support (Bhavsar et al., 2021) and are at a greater risk for suicidal behaviours (Yates et al., 2019). This means that PLEs are useful “markers” for those at risk of poor mental health outcomes (Staines et al., 2022).

This can help with prevention and early intervention. Psychotic-like experiences are very easy to screen for, and self-report measures are considered to be accurate (Kelleher et al., 2011). However, people usually do not volunteer that they have had such experiences unless they are specifically asked about it. This is most likely due to the stigma associated with psychosis (Healy and Cannon, 2020).

Psychotic-like experiences and early intervention

A recent study of health service users in the UK who were receiving treatment for anxiety and depression, found that PLEs reliably indicated treatment response and how long it would take an individual to recover in these services (Knight et al., 2020). This suggests that an intervention to reduce PLEs would improve recovery from mental illness.

Psychotic-like experiences and prevention

A previous study by our group examined whether school-based interventions could prevent psychotic- like experiences (Staines, Healy, Corcoran, et al., 2023). We found that screening for mental health problems and referral to a mental health professional effectively reduced the rate of psychotic-like experiences at 12-month follow-up. Another study in college students found that a resilience intervention over four sessions to improve resilience could effectively reduce the rates of psychotic-like experiences over a 12-month period, (DeTore et al., 2022).

Interventions or treatments for PLE urgently need further research, using randomised control trial studies, because by reducing or preventing PLEs, one can potentially reduce the risk of later mental illness.

Psychotic-like experiences and public mental health

Public mental health is an emerging field of health which is concerned with improving mental health in the population, preventing mental illness and providing adequate support to those with a mental disorder (Campion et al., 2020). Mental disorders are the most burdensome health issue globally, accounting for 32% of years lived with disability, particularly in young people (Vigo et al., 2016).

According to the World Health Organisation (WHO), one in seven adolescents will experience a mental disorder, and mental health accounts for 13% of the global burden of disease in this age group (WHO, 2021). The human, social, vocational and economic costs of serious and/or persistent mental disorders are both significant and devastating (Healy & Cannon, 2020).

One prevention challenge is identifying those at risk for developing a mental disorder. There are many genetic and environmental risk factors, which can interact to increase an individual’s risk. However, many of them cannot practically be changed at a clinical level. We need risk markers or indicators that can be easily assessed, clearly identified, occur before the onset of a mental disorder, and be modified to be used in public mental health intervention and prevention. As outlined above, PLEs fulfil all these characteristics and are a very promising target for preventive measures.

Research in the field of psychotic-like experience has expanded rapidly in the last twenty years, but there is still a substantial gap between research and clinical implementation. Research that is focused on developing interventions for PLEs and their use in current services, and in the general population and, particularly young people, is critical to progressing this important area.

References

1. Bhavsar, V., Dorrington, S., Morgan, C., Hatch, S. L., McGuire, P., Fusar-Poli, P., Mills, J., MacCabe, J. H., & Hotopf, M. (2021). Psychotic experiences, psychiatric comorbidity and mental health need in the general population: A cross-sectional and cohort study in Southeast London. Psychological Medicine, 51(1), 147–157. https://doi.org/10.1017/S0033291719003106
2. Campion, J., Javed, A., Vaishnav, M., & Marmot, M. (2020). Public mental health and associated opportunities. Indian Journal of Psychiatry, 62(1), 3–6. https://doi.org/10.4103/psychiatry.IndianJPsychiatry_687_19
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7. Knight, C., Russo, D., Stochl, J., Croudace, T., Fowler, D., Grey, N., Reeve, N., Jones, P. B., & Perez, J. (2020). Prevalence of and recovery from common mental disorder including psychotic experiences in the UK Primary Care Improving Access to Psychological Therapies (IAPT) Programme. Journal of Affective Disorders, 272, 84–90. https://doi.org/10.1016/j.jad.2020.04.015
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9. Staines, L., Healy, C., Coughlan, H., Clarke, M., Kelleher, I., Cotter, D., & Cannon, M. (2022). Psychotic experiences in the general population, a review; definition, risk factors, outcomes and interventions. Psychological Medicine, 1–12. https://doi.org/10.1017/S0033291722002550
10. Staines, L., Healy, C., Murphy, F., Byrne, J., Murphy, J., Kelleher, I., Cotter, D., & Cannon, M. (2023). Incidence and Persistence of Psychotic Experiences in the General Population: Systematic Review and Meta- Analysis. Schizophrenia Bulletin, sbad056. https://doi.org/10.1093/schbul/sbad056
11. Vigo, D., Thornicroft, G., & Atun, R. (2016). Estimating the true global burden of mental illness. The Lancet. Psychiatry, 3(2), 171–178. https://doi.org/10.1016/S2215-0366(15)00505-2
12. WHO. (2021, November 17). Mental health of adolescents. World Health Organisation. https://www.who.int/news-room/fact-sheets/detail/ adolescent-mental-health
13. Yates, K., Lång, U., Cederlöf, M., Boland, F., Taylor, P., Cannon, M., McNicholas, F., DeVylder, J. E., & Kelleher, I. (2019). Association of Psychotic Experiences With Subsequent Risk of Suicidal Ideation, Suicide Attempts, and Suicide Deaths: A Systematic Review and Meta-analysis of Longitudinal Population Studies. JAMA Psychiatry, 76(2), 180–189. https://doi.org/10.1001/jamapsychiatry.2018.3514

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