Non-affective Psychotic Disorders Could Increase Risk of Dementia in Younger Patients

Patients with non-affective psychotic disorders could have a greater risk of developing dementia compared to patients with psychiatric disorders, according to a study published in published in Cambridge University Press. These findings were based on, what is believed to be, the first high-quality, up-to-date systematic review and meta-analysis to evaluate the association between non-affective psychotic disorders and future risk of dementia using worldwide data.

Investigators suggest that the increased risk was associated with those who suffered from typical and late-onset psychotic disorders, women, and individuals who were younger than 60 years of age at baseline.

“Our findings indicate that psychotic disorders are a potentially modifiable risk factor for dementia and suggest that individuals with psychotic disorders need to be closely monitored for cognitive decline in later life,” the study authors wrote.

Dementia is one of the leading disabilities around the world and a severe public health concern. Cases of dementia are estimated to double every 20 years and costs are estimated to rise into the trillions.

Risks of dementia, a condition indicated by progressive cognitive and functional decline, include depression, anxiety, post-traumatic stress disorder (PTSD), along with other psychiatric disorders. But new evidence suggests that non-affective psychotic disorders—such as schizophrenia and other delusional disorders—could predicate dementia, though this relationship is not as heavily researched.

Neuropsychiatric symptoms, such as hallucinations, may increase someone’s risk of dementia, and they are associated with psychotic disorders; however, they could also be an early onset symptom. This led researchers to try to quantify the association between non-affective psychotic disorders and the risk of developing dementia.

After identifying more than 9000 retrospective register-based studies, the researchers observed an association between these non-affective disorders and dementia.

“Our meta-analysis has shown that the risk of dementia in individuals with non-affective psychotic disorders is 2.52 the risk of those without a non-affective psychotic disorder,” the study authors wrote.

Additionally, the research team found that non-affective psychotic disorders, specifically schizophrenia, accelerates aging. This could explain why younger individuals with psychotic disorders may be predisposed to cognitive decline.

The researchers also have not ruled out a reverse causation between dementia and non-affective psychotic disorder—in this case, symptoms act as markers for dementia, rather than the cause of it.

Study limitations included properly diagnosing dementia. Further, the team looked at records that may not have provided robust information on socio-demographic factors, thus losing the ability to generalize the findings across various subgroups.

Future research could look at associative risks of developing different subtypes of dementia, such as Alzheimer disease, and psychotic disorders.

“Non-affective psychotic disorders constitute an important and potentially modifiable risk factor for all-cause dementia and highlight the need to revise current models of dementia prevention across the life span…Our findings should be reflected in future clinical guidelines for the treatment and care of people living with non-affective psychotic disorders,” the study authors wrote.

Reference

El Miniawi, Sara, Orgeta, Vasiliki, Stafford, Jean. Non-affective psychotic disorders and risk of dementia: a systematic review and meta-analysis. 2022. Psychological Medicine, 1-13. doi:10.1017/S0033291722002781