Dementia is an acquired impairment of intellect produced by brain dysfunction. In the past, dementia was regarded as inevitably chronic, progressive and irreversible. More recently dementia has been viewed as a clinical syndrome that may be produced by both irreversible and reversible conditions. Recognition of the presence of a dementia syndrome should be followed by an evaluation for potentially treatable causes of the intellectual deterioration. Dementia treatment includes therapy for reversible or curable dementias and nonspecific interventions that may improve the condition of patients with progressive dementia syndromes.