Antipsychotic drugs increase the risk of stroke for people with dementia.

Behavioural and psychological symptoms, including agitation, psychosis, depression and aggression, occur in up to half of those with dementia in the community and in an even higher proportion of those in residential care. Antipsychotic drugs have been widely prescribed for these symptoms but have deleterious side effects such as extrapyramidal symptoms (uncontrolled movements) sedation, metabolic disturbance, increased cognitive impairment, and severe sensitivity reactions in those who have dementia with Lewy bodies. In 2004, it emerged that the risk of stroke was three times higher in people with dementia who were treated with the atypical antipsychotics olanzapine and risperidone.