Behavioural problems associated with dementia: the role of newer antipsychotics

Behavioural disorders are a common feature in dementia, especially in the later stages of the disease. The most frequent disorders are agitation, aggression, paranoid delusions, hallucinations, sleep disorders, including nocturnal wandering, incontinence and (stereotyped) vocalisations or screaming. Behavioural disorders, rather than cognitive disorders, are the main reason why caregivers place patients with dementia in a nursing home. However, although behavioural disorders are important, there is still no international agreement with respect to the description and definition of symptoms and syndromes. This also holds true for the wide variety of scales for quantification and measurement of behavioural disorders. Drug therapy should be considered after possible underlying causes such as physical illness, drug adverse effects and environmental stressors have been ruled out, or specifically addressed, and a behavioural approach has also failed. This article briefly reviews the evidence for non-antipsychotic drug therapies, which include a variety of substances. However, antipsychotics are the group of drugs which have been most frequently studied for the treatment of behavioural syndromes in dementia. Drug responsive symptoms include anxiety, verbal and physical agitation, hallucinations, delusions, uncooperativeness and hostility, whereas wandering, hoarding, unsociability, poor self-care, screaming and other stereotyped behaviour seem to be unresponsive to all drugs. Although the use of classical antipsychotics is limited by extrapyramidal symptoms, anticholinergic adverse effects, sedation and postural hypotension, the newer antipsychotics offer the chance of a better risk:benefit ratio. This article reviews the small amount of data published on the use of the newer antipsychotics, and concludes that risperidone at low dosages (0.5 to 2 mg/day) seems to be especially useful for the treatment of behavioural symptoms in dementia because of its negligible anticholinergic adverse effects. The use of clozapine is limited by its anticholinergic activity, at least in dementia of the Alzheimer and Lewy body types. However, in patients with psychosis arising from Parkinson's disease it seems to be the drug of choice, and similar activity is likely for olanzapine. There are no published data on other newer drugs, such as sertindole, quetiapine or ziprasidone. Future studies should also address questions of dementia heterogeneity and should compare different drug treatments and treatment combinations.