Clear rules about stopping treatment in individual patients are needed

The article by Ballard et al in this issue (p 874) offers an opportunity to discuss the role of drugs in the treatment of Alzheimer's disease and related dementias.1 This investigator driven randomised clinical trial has tested the hypothesis that the atypical neuroleptic quetiapine and the cholinesterase inhibitor rivastigmine would be better than placebo for treating agitation in institutionalised patients in severe stages of Alzheimer's disease. Using measures of agitation (the Cohen-Mansfield agitation inventory) and cognition (the severe impairment battery) appropriate for this stage of dementia, the authors showed that agitation improved equally in the three arms of the trial but a measurable decline in cognition occurred in patients taking quetiapine. …