Swedish scientists found dementia patients taking selective serotonin reuptake inhibitors (SSRIs) suffered a more rapid decline in brain function compared to those not given the drugs.
In the study, experts from the Karolinska Institute examined data from nearly 19,000 dementia patients with an average age of 78.
Of these about a fifth were prescribed antidepressants and the majority (65 per cent) were taking SSRIs.
Experts followed patients for an average of four years and compared the results of memory tests, measuring the ability to recall information such as the date, year and lists of words, over time.
Those on the drugs saw their score, measured out of a possible 30 points, decrease by an extra 0.3 points per year compared to those not being treated for depression.