[The Dutch College of General Practitioners' practice guideline 'Delirium in elderly people'; response from psychiatry].

Delirium is a common psychiatric illness among the medically ill and is associated with significant morbidity and mortality. Although delirium may develop at any age, the elderly are particularly vulnerable. Since the number of elderly with chronic diseases, dementia, sensory handicaps and the use of several (anticholinergic) medications--all predisposing factors for delirium--is rising, it is essential that general practitioners can recognise, adequately diagnose and treat delirium. This guideline may aid the general practitioner in diagnosing and treating this generally underestimated psychiatric disturbance in somatically ill elderly patients. Evidence on clinical features, differential diagnosis, prevalence, course, aetiology, and risk factors for delirium in primary care is lacking. In general hospitals, the prevalence of delirium in the elderly is about 10-40%; it is probably much less in primary care. This guideline does not provide an adequate description of the clinical presentations of delirium, and does not sufficiently stress the importance of recognising any new behavioural problem in an elderly patient as an indication of possible delirium.