New research led by the University of Plymouth (UK) has shown that the anti-depressant mirtazapine has no effect on agitation in a clinical trial in people with dementia. Findings were published in The Lancet journal on 23 October. The SYMBAD Phase III trial was a parallel-group, double-blind and placebo-controlled trial evaluating the safety, clinical and cost effectiveness of mirtazapine in people with dementia and agitated behaviours. The trial enrolled 204 UK participants who received either mirtazapine (45 mg) or placebo daily for 12 weeks and were followed up for up to one year. The primary outcome of the trial was the clinical effectiveness of mirtazapine in terms of reduction of agitation, measured by the Cohen-Mansfield Agitation Inventory (CMAI) score at 12 weeks.
The results showed that the mean CMAI scores at 12 weeks were not significantly different between participants receiving mirtazapine and those receiving placebo. While there were similar levels of adverse effects in both groups, there were also more deaths in the group of participants who received mirtazapine (n=7) than in the group of those who received the placebo (n=1) by week 16. Researchers concluded that the data from this study do not support using mirtazapine as a treatment for agitation in dementia.