Patients with increasing symptoms of depression are at higher risk of developing dementia. However, treatment of depression reduced this risk, according to a recent study published in the journal Biological Psychiatry.¹

To investigate the association between depression and the incidence of new-onset dementia, 354,313 participants were enrolled in this study from 2006 to 2010. The selected subjects, with ages ranging between 50 to 70 years, were a part of the UK Biobank database. More than half (~54%) were women. Follow-up was done up to 2020. The study subjects were further categorized in 4 subgroups to examine the impact of various stages of depression (increasing depression symptoms over time, decreasing depression symptoms over time, chronically high depression symptoms and chronically low depression symptoms). The effect of anti-depression treatment was also studied on the risk of dementia in four subgroups (untreated, pharmacotherapy, psychotherapy and combination).

Over the course of the study, 46,280 participants were diagnosed with depression at the start of the study. Of these, 725 developed dementia during the follow-up period.

Compared to subjects with no depression, the overall risk of dementia increased by 51%. Patients with increasing, chronically high and chronically low symptoms of depression were at higher risk, while no such effect was noted between risk of dementia and decreasing symptoms. They had comparable risk as those without depression. The risk declined by 26% among patients with depression who received treatment for their symptoms with a hazard ratio of 0.7. The risk was 42% lower after treatment among patients with increasing symptoms and 29% lower in patients chronically low symptoms of depression. However, such an effect was seen in the chronically high symptoms group.

This study shows that patients with depression were more likely to develop new-onset dementia later in life. It also demonstrates that treatment of depression reduces the odds of dementia. Timely diagnosis and initiation of anti-depression treatment is necessary to check the progression of depression; at the same time, it may also reduce the individual’s risk of dementia as demonstrated in this study.

Reference

1. Yang L, et al. Depression, depression treatments, and risk of incident dementia: a prospective cohort study of 354,313 participants. Biol Psychiatry. September 03, 2022. DOI:https://doi.org/10.1016/j.biopsych.2022.08.026