How does our mental wellbeing affect our brain health?

Much of my research looks at how mental health and brain health are connected – but first, let’s explore how these two things are different.

When we talk about mental health, this is related to our psychological and emotional wellbeing. This might include:

• our sense of purpose and control over our lives,
• our ability to feel pleasure or be optimistic,
• and our ability to cope with change, and with life’s challenges.

On the other hand, when we talk about brain health, we mean its physical health. Good brain health is about making the most of your brain and reducing the risk of developing diseases like Alzheimer’s that break down the connections between its cells. Our brain health affects our ability to plan, think, reason, and remember.

It stands to reason that someone who is struggling with their mental health may also have problems with their thinking and memory. Most of us can think of times when our wellbeing has dipped and everyday tasks seemed harder to carry out. But we still have a lot to learn about exactly how the two are connected.

How mental wellbeing and brain health are connected: what we know so far

Studies have shown that people with anxiety and depression tend to have a higher risk of dementia. In fact, one important report on dementia risk estimated that depression may be linked to 4% of all dementia cases worldwide.

Although we know there’s a link, it’s not yet clear why this is the case. We also know that people with dementia are sometimes misdiagnosed with depression. The two conditions can be difficult to tell apart when someone is in the very early stages of dementia.

But we don’t yet have good evidence to know whether improving someone’s mental wellbeing could also help their brain health and reduce their risk of developing dementia. That’s what my team and I have set out to investigate, thanks to funding from Alzheimer’s Research UK.

How we’re searching for more answers

For this project, we’re using data from several large, long-running studies and research databases. Together, these studies have tracked the mental and physical health of thousands of volunteers for decades. We plan to investigate changes in people’s thinking and memory over time, and explore whether there are any links to their wellbeing and how positive they feel about their lives.

We’ll also look at the results of brain scans and DNA samples. We want to learn whether wellbeing is connected to specific changes in the brain, including parts of the brain that are important for memory. And we’ll investigate whether genes linked to good mental health and wellbeing may also affect a person’s brain health.

There isn’t a gene that causes depression or anxiety, and much like dementia, having a parent with one of these conditions doesn’t mean you’ll develop it too. But studies have shown that people with a combination of certain genes tend to have a more positive outlook on life than average. This suggests that these genes may help lower our risk of poor mental health. For this part of our research, we want to find out whether they may also have an impact on a person’s ability to think and remember.

Our study is due to run until the winter of 2025, and we’re excited to be able to learn more about wellbeing, brain health and dementia risk. Ultimately, we hope the results will give us new tools to help people not only improve their mental wellbeing, but look after their brain health too.

Where to find help

We may still be searching for answers on some big questions about mental wellbeing and brain health. But one thing is clear: there are many good reasons to ask for help if you’re struggling with your own mental health. If you’re worried, your first port of call should always be your doctor, who can help you find the right support.