Canadian researchers have found that an antidepressant works as well as a commonly prescribed antipsychotic medication in treating aggressive behaviour in people with Alzheimer's disease - but without the severe side-effects.
The study, published in the online American Journal of Geriatric Psychiatry, is believed to be the first head-to-head comparison of an SSRI (selective serotonin reuptake inhibitor) antidepressant and an antipsychotic in non-depressed patients.
The researchers say the findings are exciting because they raise the possibility of a new direction in drug treatment for psychotic disorders related to dementia in the elderly.
"We didn't expect that an antidepressant would have so-called antipsychotic properties," said study co-author Dr. Benoit Mulsant, with the Geriatric Mental Health Program at the Centre for Addiction and Mental Health (CAMH).
However, they point out that antipsychotics continue to be the first-line treatment for Alzheimer's-related psychosis and more studies are needed to confirm their findings.
Dr. Mulsant and Dr. Bruce Pollock, also with CAMH and the Rotman Research Institute at Baycrest, conducted a study on patients who had been hospitalized with psychiatric disturbances related to dementia.
In the 12-week study, 53 patients were given the antidepressant citalopram and 50 received the antipsychotic risperidone.
The researchers were surprised to find that the two drugs had similar efficacy in reducing psychosis (hallucinations, delusions, suspicious thoughts) and agitation. Overall, there was a 32 per cent reduction of symptoms with citalopram and a 35 per cent reduction with risperidone.
But citalopram was associated with significantly fewer side effects, such as sedation, tension and apathy. Total side effect burden scores increased 19 per cent for risperidone and decreased by four per cent with citalopram.
Some antipsychotics have been associated with early death when used to treat the psychosis that often accompanies Alzheimer's.
In fact, in 2005, both Health Canada and the U.S. Federal Drug Administration ordered manufacturers of risperidone and other "atypical antipsychotics" to put a "black box" warning on their products after they were found to increase the risk of early death in elderly patients.
