A new study has found that the positive effects of antipsychotic medication for people with Alzheimer's disease are more often offset by the side-effects.
The medication is often given because people with Alzheimer's disease commonly suffer from delusions or aggression, making their care particularly challenging.
Previously to the study, it had been thought that the drugs were very helpful in allaying symptoms.
"We thought overall the drugs would show their effectiveness," said Professor Lon Schneider.
"The answer is yes, they are somewhat effective, but overall the efficacy is offset by adverse events that resulted in discontinuing the medication.
"It was a surprise, in that the expert opinion which drove this study was that these drugs are particularly useful in treating these difficult symptoms."
The US study involved 421 participants and is published in the New England Journal of Medicine.