Study Sheds Light on Mental Illness and Dementia

“Certain mental conditions, particularly depression and schizophrenia, have also been linked to dementia. But because depression can itself be a sign of cognitive decline, the causality has been a bit muddy,” Claudia Wallis writes for Scientific American. “Earlier this year an analysis of data from New Zealand provided the most convincing evidence to date linking many kinds of mental illness with dementia. That study raises important questions about the reasons for this increased risk and what could be done to reduce it.

“The study looked at the health records of 1.7 million New Zealanders born between 1928 and 1967 covering a 30-year period ending in mid-2018. It found that those with a diagnosed mental disorder – such as anxiety disorders, depression or bipolar disorder – had four times the rate of ultimately developing dementia compared with people without such a diagnosis. For those with a psychosis such as schizophrenia, it was six times the rate. Among people who developed dementia, those with a psychiatric disorder were affected 5.6 years earlier, on average,” Wallis writes.

“Could a more holistic approach to treating mental illness mitigate the risk for dementia? Researchers tend to think so.”

Original article by Claudia Wallis, Scientific American, July 2022.

Illustration by Fatinha Ramos.