The researchers analyzed evidence from 11 studies conducted in 9 countries on 4 continents, which included approximately 13 million participants.
Psychotic disorders may have a stronger link with dementia than other mental health disorders, such as depression or anxiety, according to the authors of a recently published systematic review. The analysis is the first to assess a range of psychotic disorders and their association with dementia risk. Psychotic disorders, such as schizophrenia, are severe illnesses that involve symptoms such as hallucinations and delusions and social withdrawal, as well as impairments in cognitive and functional skills.
"We found that having a diagnosis of a psychotic disorder is linked to a much higher risk of developing dementia later in life,” said senior author Jean Stafford, MD, in a press release. "Our findings add to evidence that protecting people's mental health throughout life could help to prevent dementia."
The researchers analyzed evidence from 11 studies conducted in 9 countries on 4 continents, which included approximately 13 million participants. During their assessment of the data, the team observed a higher risk of dementia later in life across multiple psychotic disorders, regardless of the age of the mental illness was first developed. In some studies, there were participants who were diagnosed with psychotic disorders while young adults, with follow-up periods of multiple decades.
Additionally, the investigators observed that patients who have had a psychotic disorder tend to be younger than average at dementia diagnosis, with 2 studies finding that people with psychotic disorders were more likely to be diagnosed while still in their 60s.
Previous studies found that 4 in 10 cases of patients with dementia could be prevented or delayed by targeting risk factors from across their lifespans. In this study, the authors also found that experiencing post-traumatic stress disorder during a patient’s lifespan can increase the likelihood of dementia. However, the investigators observed that the strongest association with dementia risk was with psychotic disorders.
Furthermore, during the study the research team was still not able to confirm the cause of the association between dementia risk and psychotic disorders. Specifically, they were unable to determine whether the association is due to the psychotic disorder itself or due to these disorders potential for increasing the likelihood of conditions that increase the dementia risk.
"People with psychotic disorders are more likely to have other health conditions such as cardiovascular disease or obesity, which can increase the risk of dementia, while they are also more likely to have a poor diet, smoke or use drugs, which may harm their health in ways that could increase their likelihood of developing dementia,” Orgeta said in the press release.
The researchers were also not able to determine whether effective treatment for psychotic disorders could lessen the risk of dementia, or whether antipsychotic medication could be a factor due to limited and conflicting evidence.
"As people with psychotic disorders face a higher risk of numerous other health conditions, managing their overall physical and mental health is very important, and here we found that health professionals working with them should also be watchful for any signs of cognitive decline,” said lead study author Sara El Miniawi in a press release.
Schizophrenia may increase dementia risk by 2.5 times. ScienceDaily. October 6, 2022. Accessed October 12, 2022. https://www.sciencedaily.com/releases/2022/10/221006092313.htm