title: Symptoms of delirium: an exploratory factor analytic study among referred patients.
abstract: OBJECTIVE
  Factor analytic studies of delirium symptoms among patients referred through consultation-liaison psychiatric services are rare. We examined the factor structure of delirium symptoms in referred patients and determined whether combining items from several delirium rating scales influenced the factor structure of delirium symptoms.
  
  
  METHODS
  Eighty-six patients with delirium (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision) referred though the consultation-liaison services were assessed with structured rating scales. Nineteen symptom items extracted from the Delirium Rating Scale-Revised-98 (DRS-R-98), the Memorial Delirium Assessment Scale and the Confusional State Evaluation Scale were subjected to an exploratory (principal component) factor analysis. A second such analysis was conducted on 15 items of the DRS-R-98 for comparison.
  
  
  RESULTS
  Compared with prior studies, patients were younger and the majority had hyperactive delirium. Principal components analysis identified two factors: (1) a "cognitive" factor comprising of disturbances in language, thought processes, orientation, attention, short- and long-term memory, visuospatial ability, consciousness (awareness) and perseveration accounted for 28.9% of the variance and (2) a "behavioral" factor consisting of sleep-wake cycle disturbances, delusions, perceptual disturbances, motor agitation, affect-lability, distractibility, irritability and temporal onset accounted for 18.9% of the variance. An identical factor structure was obtained with the DRS-R-98 items.
  
  
  CONCLUSIONS
  Similar to previous factor analytic studies, the present study supported the existence of two principal dimensions of delirium, cognitive and behavioral. Additionally, it extended the results of earlier investigations to a wider group of patients with delirium, suggesting that these dimensions might provide important clues to the neurobiology of delirium.
authors.affiliation: Department of Internal Medicine and Psychiatry (Med-Psych), Southern Illinois University School of Medicine, Springfield, IL, USA. gjain@siumed.edu
authors.forename: Gaurav
authors.initials: G
authors.lastname: Jain
authors.forename: Subho
authors.initials: S
authors.lastname: Chakrabarti
authors.forename: Parmanand
authors.initials: P
authors.lastname: Kulhara
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003693:Delirium / Q000503:physiopathology*; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010361:Patients / Q000523:psychology*; D012017:Referral and Consultation; D055815:Young Adult