Having a diagnosis of depression in midlife or late-life may increase your risk of dementia, a new study by researchers from the University of Adelaide has found.
The research team, who also came from the University of Nottingham and Curtin University, carried out an umbrella review of eight studies and meta-analysis of 18 previous studies to explore the link between the conditions and published their findings in eClinicalMedicine.
Lead author Jacob Brain, inaugural University of Nottingham and University of Adelaide Joint PhD scholarship program recipient, said the results highlighted a consistent relationship between late-life depression and risk for all-cause dementia.
More than 57 million people worldwide are affected by dementia, and while previous studies have shown people with depression are more likely to develop dementia later in life, debate has continued around when it matters most, in midlife or later life.
"Our study shows that depression is linked to an increased risk of dementia in both midlife and late life," says Mr Brain.
"This highlights the importance of recognising and treating depression across the life course, not just for mental health, but also as part of a broader strategy to protect brain health.
"Public health efforts need to place greater emphasis on preventative brain health, including scaling up access to effective mental health care."
The potential links between depression and dementia are complex, can include chronic inflammation, dysregulation, vascular changes, and imbalances. Shared genetic and behavioural related changes may also increase the risks.
"It is a complex relationship and likely reflects multiple interacting factors," says Mr Brain.
"Depression in late life may represent an early manifestation of dementia, with common symptoms including impaired concentration, attention and other aspects of executive functioning but it may also reflect underlying neurobiological changes that precede the cognitive symptoms
"Depression itself may accelerate cognitive decline through mechanisms linked to chronic inflammation and vascular dysregulation which further weaken neural resilience.
"Our findings raise the possibility that depression late in life may not just be a risk factor, but it could also be an early warning sign of dementia beginning to develop.
"By clarifying this timing, our work helps guide future research, treatment, and prevention strategies."
