Characteristics and outcome of delirium in psychiatric inpatients.

Delirium, a transient organic psychiatric syndrome, is a common psychiatric diagnosis. It is associated with increased rates of morbidity and mortality in medical-surgical inpatients. There have been few reports describing the risk factors and prevalence of delirium among psychiatric inpatients. The purpose of the present study was to investigate the rate of delirium, the reasons for admission, the clinical features, the etiologies and the mortality during a 2 year follow-up in psychiatric inpatients admitted to a general hospital during a 3 year period. The results show that the rate of incidence of delirium in psychiatric and geriatric (age > or = 65 years) inpatients was 1.4 and 9.6% respectively. The most common cause of delirium was adverse effects of medication. The inpatient mortality (5.9%) was lower compared with reported mortality rates in medical-surgical inpatients. However, there was a high mortality rate during the 2 year follow-up period (39.4%), especially in older patients. The high mortality during follow-up stressed the importance of after-discharge care in these patients.