People who suffer from mental health issues early in life have been found to be at a higher risk of getting dementia when they’re older, according to a new study.

The study, which was published last Thursday, looked at various health indicators such as hospitalisations to assess mental health, hospitalisations and pharmaceutical use, and mortality records to assess any links to dementia.

About 1.7 million New Zealanders, born between 1928 to 1967, took part in the University of Auckland study. They were followed for three decades from 1988 to 2018. 

Associate Professor Dr Barry Milne, who co-authored the study, said the research found that people who had mental health hospitalisations were three and a half times more likely to present with dementia later in life.

This was true for both men and women of both early and late dementia, Milne said. 

Early dementia refers to people in their 50s with the disease. 

“It didn't matter what type of mental health condition people were admitted to hospital for, there was still an increased risk of dementia.”

But this does not mean that mental health issues are the cause of dementia later in life, he said.

“We just made a connection between mental health hospitalisation and dementia, it may be causal and may not be causal.

“If it is causal, or if there are other things on the causal pathway, then people with mental health disorders would be advised to take some precautions that might otherwise raise the risk of dementia.”

Milne said there were a lot of people who got dementia, and the longer you lived, the more likely you are to get it. 

A good precaution would be adjusting two common behaviours seen in people who have mental health issues, which are excessive alcohol use and physical inactivity, he said.

“Both have been implicated in dementia, so if people are concerned then that’s the sort of precaution they might consider taking,” Milne said.

”We’re not saying ‘if you've got mental health problems, you're destined to get dementia’. It's not like that. But amongst other risk factors that are known for dementia, we need to add mental health disorders.”

Co-author Dr Stephanie D’Souza said “it's not a life sentence by any means”.

“If you struggle with mental health issues, that doesn't mean that you will go on to develop dementia but getting help and doing what you can to support yourself is always great,” she said.

“Mental health conditions tend to peak in early adulthood or adolescence so, for young people, this is important to be aware of.”

“One thing we would encourage is, for individuals with mental health conditions who are struggling, to engage in services or in behaviours that reduce their dementia risk,” she said. 

She also said good health practices will benefit anyone wanting to reduce the risk of dementia.

“Things like exercising, minimising substance use and drinking alcohol, are general positive health behaviours that would support both your physical health as well as your mental health,” D’Souza said.

“And it would have the long-term benefit of reducing your risk of dementia.”

Where to get help:

  • 1737: The nationwide, 24/7 mental health support line. Call or text 1737 to speak to a trained counsellor.
  • Suicide Crisis Line: Free call 0508 TAUTOKO or 0508 828 865. Nationwide 24/7 support line operated by experienced counsellors with advanced suicide prevention training. 
  • Youthline: Free call 0800 376 633, free text 234. Nationwide service focused on supporting young people.
  • OUTLine NZ: Freephone 0800 OUTLINE (0800 688 5463). National service that helps LGBTIQ+ New Zealanders access support, information and a sense of community. 

Top image: Depressed kid during epidemic quarantine. (File photo) @Ridvan_celik Photo: iStock

More stories:

Aotearoa finally bans conversion therapy

Re Covid parties or isolation: Flatters share personal pandemic plans as cases rise

NZ scientists find solutions for the PPE waste crisis