Behavioural and psychiatric disturbances affect at least 50% of people with Alzheimer's disease and other dementias. Neuroleptic drugs are extensively prescribed to treat behavioural manifestations of dementia in spite of only modest efficacy and a high frequency of adverse effects. There is clearly a need for safer and more effective remedies. Trazodone is a psychoactive compound with sedative and antidepressant properties, and with mixed serotonin agonist and antagonist effects. Functional serotonergic deficits may be related to the genesis of behavioural disturbances in dementia.