Etiologic and Cognitive Differences in Hyperactive and Hypoactive Delirium

Article AbstractObjective: To assess the differing patterns of cognitive impairment in the hyperactive and hypoactive subtypes of delirium and test the hypothesis that cognitive disturbances are high in patients with hypoactive delirium. Method: The study was conducted in a general hospital in Pune, India from 2007 to 2009 and included 80 patients with delirium (DSM-IV-TR criteria). A detailed sociodemographic profile was obtained for each patient, and their cognitive function was assessed with the Mini-Mental State Examination (MMSE) and Memorial Delirium Assessment Scale (MDAS). Patients were classified as hyperactive or hypoactive using the MDAS. Results: Of the 80 patients, 70% (n = 56) were identified as hyperactive, with a mean ± SD age of 33.42 ± 7.37 years, and 30% (n = 24) as hypoactive, with a mean ± SD age of 34.62 ± 6.64 years. Alcohol and other substance use disorders were the most frequent diagnosis associated with the hyperactive subtype, whereas other psychiatric disorders such as schizophrenia and mood disorders, infection, and chronic medical conditions were associated with the hypoactive subtype. Cognitive impairments were significantly high in the hypoactive subtype, as found in various cognitive domains of the MMSE and MDAS (P = .000).Conclusions: The hyperactive and hypoactive subtypes of delirium appear to be etiologically associated with a different diagnostic group. Severe cognitive impairment was associated with the hypoactive subtype.