Study finds no association between trazodone and reduced dementia risk

In a large UK population-based study, Ian Wong and colleagues at the University of Hong Kong and University College London, UK, found no statistically significant association between the antidepressant trazodone and a reduced risk of dementia when compared to other antidepressants. Their findings were published this week in PLOS Medicine.

In vitro and animal studies have previously suggested that trazodone may protect against dementia. In the new study, researchers analyzed data from the Health Improvement Network (THIN), which includes medical records of over 15 million primary care patients in the UK. They identified 4,716 people over the age of 50 years who received at least two consecutive trazodone prescriptions between 2000 and 2017, and compared them with 420,280 users of other antidepressants with similar baseline characteristics.

The median time to dementia diagnosis for trazodone users was 1.8 years. The incidence of dementia among trazodone users was higher than in matched antidepressant users (1.8 vs 1.1 dementia cases per 100 person-years) with a hazard ratio of 1.80 (95% confidence interval 1.56-2.09, P < 0.001). However, the results do not point toward a causal association; the study is limited by the fact that people in the prodromal stage of dementia might be preferentially prescribed trazodone.

"These results refute the suggestions from animal studies that trazodone might stop or delay the onset of dementia in patients at the prodromal stage of dementia," the authors say.