[Delirium in old age. Difficulties in diagnosis]

Confusion is a frequent psychiatric and behavioural manifestation of diffuse cerebral injury found in elderly patients that are severely ill or stressed. The hyperactive form is often recognised because of the psychomotor agitation. However, the hypoactive form is most frequent and has a worse prognosis. Despite, it is often under-recognised. Among contributing factors, anticholinergic agents and drug interactions are significant. Identification and treatment of the underlying cause of delirium is essential with a focus on non pharmacological approach. Antipsychotic agents are reserved for severe forms and where non pharmacological intervention fracases.