04 Jan Psychotic Experiences and Cognitive Deficits Affects Large Proportion of Population
MedicalResearch.com Interview with:
Josephine Mollon MSc
Department of Psychosis Studies
Institute of Psychiatry, Psychology, and Neuroscience
King’s College London
Medical Research: What is the background for this study? What are the main findings?
Dr. Mollon: Psychotic symptoms, such as hallucinations and delusions, are core features of psychotic disorders. A significant minority of the general population also reports subclinical psychotic experiences. Evidence suggests that these experiences may lie on a continuum with clinically significant psychotic symptoms. For example, cognitive deficits, which are a hallmark of psychotic disorders, are also seen in people with subclinical psychotic experiences. We used population-based survey data to characterize cognitive functioning in adults with psychotic experiences while adjusting for important sociodemographic characteristics and investigating the effect of age.
The 171 (9.7%) adults with psychotic experiences showed significant memory and verbal deficits, but not IQ or processing speed deficits. Only participants 50 years and older with psychotic experiences showed medium to large impairments in general IQ, verbal knowledge, working memory and memory after adjusting for socioeconomic status, cannabis use, and common mental disorders.
Medical Research: What should clinicians and patients take away from your report?
Dr. Mollon: Those with subclinical psychotic experiences did not show an impairment in processing speed, which is severely compromised in psychotic patients, suggesting that processing speed deficits indicate vulnerability to psychosis. Moreover, psychotic experiences, together with cognitive deficits, may be most challenging in those aged 50 years and older. Even mild, subclinical psychotic experiences, when combined with the effects of aging, may strain cognitive reserves and lead to large, burdensome cognitive deficits. Finally, our findings suggest a continuum of psychotic experiences and cognitive deficits in a much larger proportion of the population than that seen in clinical practice. Effective treatment of such deficits could be helpful for many individuals.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Mollon: Longitudinal studies are needed to elucidate how psychotic experiences interact with cognitive deficits throughout the life course and to identify risk and resiliency factors.
Josephine Mollon MSc (2016). Psychotic Experiences and Cognitive Deficits Affects Large Proportion of Population