Depression and dementia are a major health challenge for older people and their carers. Although antidepressants are recommended, their effect on depressed people with dementia is still unclear. In a review, researchers from Bern and Ulm were unable to find any evidence of a clinical effect of antidepressants. This could be due to the structural changes in the brain that are associated with dementia. The meta-study was published in the scientific journal "Psychiatry Research".
Depression and dementia significantly affect older adults and lead to a reduced quality of life and independence. Almost a third of older adults with mild to moderate dementia also suffer from a major depressive disorder. Depression is associated with a higher risk of dementia and is also considered a neuropsychiatric symptom of dementia. Furthermore, depression can be one of the first symptoms heralding dementia, highlighting the complex relationship between these two conditions.
"In contrast to 'normal' depression, the effectiveness of antidepressants in the treatment of depression in dementia is not well established," explains Dr Eric Lenouvel from the University Clinic for Geriatric Psychiatry and Psychotherapy in Bern, Switzerland, and lead author of the study. Some research suggests that antidepressants may even worsen symptoms, while a recently published independent Cochrane review does not provide conclusive evidence of their effectiveness due to a lack of comprehensive studies. "This uncertainty is at odds with common practice, where antidepressants are prescribed to older people for major depression and often lead to polypharmacy in care homes when people are taking at least five different drugs at the same time and on a sustained basis," Dr Lenouvel added.
In the review, the researchers from Bern and Ulm University Medicine and the Institute for Geriatric Research at the Agaplesion Bethesda Clinic in Ulm were primarily interested in the effect of all types of antidepressants on the extent of depressive symptoms. Secondly, the cognitive state, quality of life and functionality of those affected were of secondary importance. Of 14 selected studies, eight contained sufficient data for a quantitative synthesis with a total of 617 participants, 160 of whom suffered from mild and 457 from moderate to severe depression. The study results could not confirm an effect of the antidepressants based on the studies analysed. Nevertheless, the certainty of the results is only considered to be moderate; due to imprecision, they also had to be downgraded. Furthermore, the review does not cover all the research in this area.
"The lack of clear efficacy may suggest that depression develops differently in older adults with dementia. It is therefore important to study older adults separately," says Professor Carlos Schönfeldt-Lecuona, who coordinated the study. The psychiatrist works in the Department of Psychiatry and Psychotherapy III at Ulm University Hospital. Cerebral structural changes associated with the various forms of dementia, dysregulation of neurotransmitters, altered metabolism and altered permeability of the blood-brain barrier may all play a role.
In view of the global trend of an ageing population and the increasing prevalence of dementia, the researchers conclude that effective diagnosis and treatment of depression in dementia patients is becoming increasingly important.
The research was carried out as part of the joint project "Medication and life situation in old age" of the medical faculties of Heidelberg, Ulm and Freiburg, which is funded by the open funding line of the special medical line of the Baden-Württemberg university funding agreement.
Publication reference:
Eric Lenouvel, Sebastian Tobias, Viktoria Mühlbauer, Dhayana Dallmeier, Michael Denkinger, Stefan Klöppel, Carlos Schönfeldt-Lecuona; Antidepressants for treating depression among older adults with dementia: A Systematic Review and Meta-Analysis, Psychiatry Research (2024), https://doi.org/10.1016/j.psychres.2024.116114
Text and media contact: Daniela Stang