Depression Linked to Increased Dementia Risk, Study Finds

Main Findings From A 15 Year Study

The International Journal of Geriatric Psychiatry recently published a research paper, showing a strong connection between depression and an increased rate of dementia. The study carried out in the course of 15 years revealed that patients who had been diagnosed with depression at the beginning of the research were almost 74% more likely to develop dementia than those without depression. Moreover, dementia appeared two years earlier among depressed individuals. These findings demonstrate the urgent need for timely identification and management of depressive symptoms; this may help preventing possible future decrease in cognitive ability.

An Aging Population And The Risk Of Dementia 

The population is getting older globally, with over-65s set to increase from 703 million people in 2019 to around 1.5 billion by 2050. This demographic change will lead to a significant rise in people living with dementia: figures are expected to increase from 47.5 million cases recorded in 2015 up to roughly estimated by UN DESA at about 135.46 million sufferers predicted for 2050. We need to understand and reduce risk factors for dementia so as to prevent its incidence which is projected to be approximately at least 7.7 million new cases annually by public health authorities.

Understanding Dementia  

Dementia is generally a progressive decline in thinking, reasoning, memory and behavior; it includes such symptoms as memory lapses, problems solving tasks , language difficulties , poor judgement and reasoning abilities. Alzheimer’s disease is one examples of diseases or conditions that damage brain cells leading to severe intellectual decline otherwise known as dementia. Dementia mainly affects elderly people though it should not be considered normal part of aging.

Exploring The Link Between Depression And Dementia   

Previous studies have indicated that there could exist some form of connection between depression and dementia, but the exact nature of this link is still a subject of scientific discussions. For instance, some research reveals that depression may be an initial symptom of dementia; on the other hand, others suggest it might be a risk factor or complication for the disease. This study was conducted to elucidate such queries by determining if patients who were depressed at baseline are more likely to develop dementia during long-term follow-up.

Findings And Research  

“Depression can be a risk factor for developing dementia and mild cognitive impairment in a large population study,” said Nicola Veronese, one of the authors of the study and an assistant professor from University of Palermo. “Different from dementia, depression is curable by pharmacological and non-pharmacological treatments as well.” I hope our study will encourage more researches to find out if reversing depression can lower risk of developing dementia.

Methods And Main Outcomes  

The source data for this investigation was drawn from Survey of Health, Aging and Retirement in Europe (SHARE), which contains information on 50+ people in 27 European countries plus Israel. Information gathering began between 2004 and 2006 concluding with data collected until 2019/2020. EURO-D scale which assesses different aspects associated with depression including sleep quality , pessimism and concentration using twelve questions was administered to subjects to establish their levels depressive symptoms. If the score got at least four points according to EURO-D scale it means that there was depression among participants .

The study included 22,789 respondents, among whom 24.9% had depression at baseline. They were typically older, predominantly female, more often divorced and/or less educated, with higher rates of chronic diseases and limited in their daily functioning.

Throughout the follow-up period of 15 years, 1,419 subjects developed dementia corresponding to an incidence rate of 7.31 per 1000 person years. At baseline depression was significantly associated with dementia risk by 74%, and this was most pronounced in those under the age of sixty who had two times greater odds of developing dementia when having depression.

Specific Depression Symptoms as Predictors  

“The key learning here is that every time we are going to deal with a person affected by this condition they should bear in mind the cognitive aspect that comes along with depression,” said Veronese in his dialogue with PsyPost. Moreover, particular symptoms like reduced level of concentration were significant predictors for later development of dementia. For example, other depressive signs including pessimism and decreased energy were serious indicators while sleeping problems was not a predictor.

Study Limitations and Future Research  

However large sample size and long-term follow-up period did not eliminate certain shortcomings in the present study design. Accordingly, diagnosis criteria for depression relied on self-reported symptoms rather than clinical diagnoses which may introduce bias into them. As well as self-reported history f diagnosis of dementia used in this study might not have captured all cases precisely. Another limitation is that no distinction was made between different types of dementia each having its own profiles related to depression.

Accordingly: “Moreover although our findings are reliable they have limitations; one must take caution when interpreting them,” Veronese says. Additionally there is a possibility for reverse causation where initial signs and symptoms of dementia can be mistaken for depressive state though such cases are excluded from analysis if diagnosed within five years after onset.

Conclusion and Future Directions  

Further studies should aim to replicate these findings in other populations and examine whether intervention for depression can reduce the risk for dementia. Also, studies on biological mechanisms associating depression and dementia should be carried out which can provide important insights into the role of inflammation, hormonal changes and genetic predispositions.

The paper titled “Association between depression and incident dementia: Longitudinal findings from the SHARE study” was authored by Nicola Veronese, Lee Smith, Ai Koyanagi, Pinar Soysal, Christoph Mueller, Chiara Maria Errera , Giusy Vassallo , Laura Vernuccio , Giuseppina Catanese , Marco Solmi Ligia J. Dominguez , Mario Barbagallo .

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