Depression is linked to an accelerated rate of brain aging, suggests a new study published in the journal Psychological Medicine. Although there have been previous studies determining a link between depression and increased dementia risk in later life, this is the first study that provides comprehensive evidence for the effect of depression on the decline in overall cognitive function in a general population.
The study was conducted by Darya Gaysina and Amber John from the EDGE (Environment, Development, Genetics, and Epigenetics in Psychology and Psychiatry) Lab at the University of Sussex, to determine the impact of depression on the cognitive ability of a general population.
For the study, researchers conducted a robust systematic review of 34 longitudinal studies, with the focus on the link between depression or anxiety and decline in cognitive function over time. Evidence from more than 71,000 participants was combined and reviewed. Including people who presented with symptoms of depression as well as those that were diagnosed as clinically depressed, the study looked at the rate of decline of overall cognitive state – encompassing memory loss, executive function (such as decision making) and information processing speed – in older adults.
Importantly, any studies of participants who were diagnosed with dementia at the start of the study were excluded from the analysis. This was done in order to assess more broadly the impact of depression on cognitive aging in the general population. The study found that people with depression experienced a greater decline in the cognitive state in older adulthood than those without depression. As there is a long pre-clinical period of several decades before dementia may be diagnosed, the findings are important for early interventions as currently there is no cure for the disease.
Dr Gaysina, comments: “This study is of great importance – our populations are aging at a rapid rate and the number of people living with decreasing cognitive abilities and dementia is expected to grow substantially over the next thirty years.
“Our findings should give the government even more reason to take mental health issues seriously and to ensure that health provisions are properly resourced. We need to protect the mental wellbeing of our older adults and to provide robust support services to those experiencing depression and anxiety in order to safeguard brain function in later life.”
Researcher John, who carried out this research for her Ph.D. at the University of Sussex adds: “Depression is a common mental health problem – each year, at least 1 in 5 people in the UK experience symptoms. But people living with depression shouldn’t despair – it’s not inevitable that you will see a greater decline in cognitive abilities and taking preventative measures such as exercising, practicing mindfulness and undertaking recommended therapeutic treatments, such as Cognitive Behaviour Therapy, have all been shown to be helpful in supporting well-being, which in turn may help to protect cognitive health in older age.”