Depression and dementia risk
Depression is known to be a risk factor for dementia but also may be part of the disease.
Does depression increase the risk of dementia?
Depression is a mental health condition that includes symptoms of persistent low mood, tiredness and disinterest in things you normally enjoy.
Evidence shows that depression increases a person’s risk of developing dementia.
It is important to note that while there is a connection, not everyone who has depression will go on to develop dementia and not everyone with dementia will develop depression.
How to reduce the risk of dementia
A lifelong approach to good health is the best way to lower your risk of dementia.
There are some lifestyle behaviours with enough evidence to show that changing them will reduce your risk of dementia.
The link between depression and dementia
This connection between depression and dementia is complicated and how the two conditions are linked is unclear. Evidence shows that depression may be a part of the disease. It is thought that changes in the brain that happen before a person shows symptoms of dementia, may result in depression.
We don’t fully understand whether the length of depression, severity of depression or the age at which someone experiences depression affects their dementia risk.
A large study of over 46,000 people with depression showed that those who were treated by medication, psychotherapy or both had a lower risk of developing dementia compared to those who were untreated.
Another study looked at an antidepressant drug called citalopram. Citalopram is known to reduce the build-up of clumps of amyloid protein – associated with Alzheimer’s’ disease. It was found that treatment may have delayed the progression from early symptoms to clinically diagnosed Alzheimer’s disease.
Other studies suggest that certain medicines that are used for depression, called anticholinergics, might increase dementia risk. However, it may be that it is the appearance of depression, not the treatment that increases dementia risk.
Few studies have looked into the relationship between non-pharmacological interventions for depression and dementia risk. One study has shown that people who receive cognitive behavioural therapy for depression are less likely to develop dementia.
Depression is associated with roughly double the risk of developing dementia, according to a review that combined results from 27 research studies. However, there was a lot of variability between the studies included. The participants’ ages were also not taken into account. This is important as depression occurring closer in time to dementia diagnosis is more likely to be an early symptom.
Other research has tried to see whether there is a difference between late-life and early-life depression, in terms of dementia risk. Based on new research it is now believed that depression can increase the risk of dementia, whether it occurs in early adulthood, mid-life, or later life.
This shows that depression is a clear mid-life risk factor for dementia. Getting treatment for depression is important to help people feel better and may also lower their chances of developing dementia.
Alzheimer’s Society is funding research to better understand the links between depression and dementia. We are also working to better support people living with dementia who are suffering from depression or other mental health difficulties.
Further reading
Alzheimer's Society dementia support line
Call 0333 150 3456.
If you are affected by dementia, worried about a diagnosis or a carer, trained staff are ready to give you the support you need. Opening hours (excluding bank holidays): Mon to Weds: 9am – 8pm, Thurs and Fri: 9am – 5pm, Sat and Sun: 10am – 4pm.
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