This information is for people with dementia and their carers. It tells you about trazodone, a treatment that is sometimes used for dementia. It's based on the best and most up-to-date research.
Does it work?
We're not sure. There's some evidence that trazodone might help some people with dementia who are aggressive, easily upset (agitated), and restless. But other research shows that trazodone doesn't help.
What is it?
Trazodone is a drug that is normally used for treating depression. Its brand name is Desyrel.
How can it help?
We're not certain that it can. In one small study, trazodone worked as well as a drug called haloperidol, with about two-thirds of the people who took trazodone becoming less aggressive, agitated, and restless.  But in another study, trazodone worked no better than a dummy treatment (a placebo). 
How does it work?
Doctors aren't sure why trazodone should help with problems such as restlessness, irritability, shouting, swearing, pacing, and wandering. Trazodone increases the amount of a chemical called serotonin in the brain. This may help these symptoms.
Trazodone can make people feel drowsy. This also means people feel less aggressive, restless, and agitated.
Can it be harmful?
Trazodone can cause a slow heartbeat and made you feel dizzy when you stand up from sitting. But side effects from taking trazodone are not common and not usually serious.  This is one of the reasons why trazodone is often given to people who have Alzheimer's disease or other kinds of dementia.
How good is the research on trazodone?
We didn't find any good evidence that trazodone helps people with dementia become less aggressive, restless, or easily upset (agitated).
Two studies looked at people with Alzheimer's disease.   One of them also included people with vascular dementia or both Alzheimer's and vascular dementia (mixed dementia). 
Trazodone, a treatment called haloperidol and a dummy treatment (a placebo) all worked about the same for helping people become less agitated. But these studies looked at only a small number of people. Bigger studies are needed to see if trazodone can really help people with dementia.