Image of older man with cane, sitting alone

Preventing and treating mental health disorders earlier in life might reduce or delay the risk of cognitive decline, according to a new study.

Researchers at the University of Michigan examined the hospital records of 1.7 million New Zealanders, aged 21 years to 60 years at baseline, across three decades (1988 to 2018). They found that those with early-life mental disorders were at elevated risk of subsequent dementia and younger dementia onset. Specifically, among individuals diagnosed with a mental disorder, 6.1% were also diagnosed with dementia during the observation period, compared with 1.8% of those without a mental disorder.

The connection between mental health problems and dementia appeared in both men and women, for both early-onset and later-onset dementias, for different types of mental health conditions and for both Alzheimer’s and non-Alzheimer’s dementias.

Further, mental disorders were more strongly associated with dementia than chronic physical diseases, an outcome the researchers said they did not expect.  

Their findings support the need to embed dementia prevention into mental disorder treatment across the life course, said Leah Richmond-Rakerd, Ph.D., assistant professor of psychology at the University of Michigan and the study’s lead author.

For instance, mental health professionals could deliver psychoeducation to clients about health behaviors to reduce dementia risk and implement interventions targeting other modifiable dementia risk factors that are more common in patients with mental disorders, such as social disconnection, the authors wrote.

“Mental health problems are not a ‘life sentence’ that always results in dementia,” Richmond-Rakerd said in a statement.

Full findings appeared in JAMA Psychiatry.