Preventing mental illness in young people could help mitigate their risk of developing dementia later in life, new research suggests.
The study was conducted by researchers at the University of Michigan, Duke University and the University of Auckland and led by Leah Richmond-Rakerd, assistant professor in U-M’s Department of Psychology.
Researchers studied 1.7 million New Zealanders aged between 21 and 60 at baseline over three decades (1988 to 2018).
The researchers sought to discover whether individuals with mental disorders were at an increased risk of developing dementia.
The researchers found:
- Mental disorders were more strongly associated with dementia than chronic physical diseases—an outcome the researchers did not expect.
- The association between mental disorders and dementia was not explained by pre-existing chronic physical illness or socioeconomic deprivation.
- The connection between mental health problems and dementia was seen for 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.
Richmond-Rakerd said that mental illnesses are early warning signs for subsequent dementia.
The researcher said that people with mental disorders should engage in healthy behaviours that reduce their dementia risk, such as regular exercise.
The scientists do not yet know the mechanism for the association.
However, a lifelong brain vulnerability may manifest as a mental health problem in earlier life and then dementia later on, they said.
Medication for mental illness, such as antipsychotics, may also increase the dementia risk, the researchers added.
However, they cautioned that most people with mental illness will not develop dementia.
“Mental health problems are not a ‘life sentence’ that always results in dementia,” Richmond-Rakerd said.
There are currently around 900,000 people with dementia in the UK, according to the Alzheimer’s Society.
This is projected to rise to 1.6 million by 2040.
The condition affects one in six people over the age of 80.