title: Is cannabis an anti-antipsychotic? The experience in psychiatric intensive care.
abstract: BACKGROUND
  Cannabis use is a major problem in inner cities and has been causally implicated in psychosis. Very few of the available hospital-based studies of the implications of cannabis usage have involved psychiatric intensive care units (PICU); but PICU receive many of the most challenging and resource-hungry-and incompletely understood-patients in the mental health system.
  
  
  OBJECTIVE
  To study the clinical impact of cannabis abuse in a PICU, and to compare the use of atypical and typical antipsychotics in this setting.
  
  
  METHODS
  115 patients admitted to a PICU consented to take part in an open label naturalistic study. BPRS, TCI-240, weight, length of admission and routine bloods were evaluated in all participants.
  
  
  RESULTS
  There was a high rate of cannabis abuse (71.3%) in the PICU population. Patients who abused cannabis spent longer in PICU because their psychoses were more severe. They were younger at first hospital admission. Cannabis also had metabolic implications, with higher blood glucose levels at admission and greater weight increase. Atypical antipsychotics were effective in treating psychosis inpatients positive to cannabis at admission.
  
  
  CONCLUSIONS
  Our findings suggest that cannabis abusers had a more severe psychotic illness, especially in schizophrenia. There are additional complications in terms of weight gain for cannabis users.
authors.affiliation: Bethlem Royal Hospital, Monks Orchard Road, Beckenham, Kent BR3 3BX, UK. mi@stekel.demon.co.uk
authors.forename: Maria
authors.initials: M
authors.lastname: Isaac
authors.forename: Michael
authors.initials: M
authors.lastname: Isaac
authors.forename: Frank
authors.initials: F
authors.lastname: Holloway
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000494:pharmacology*; D002188:Cannabis; D003422:Critical Care; D005260:Female; D006801:Humans; D008131:London / Q000453:epidemiology; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology / Q000523:psychology; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000188:drug therapy* / Q000453:epidemiology / Q000523:psychology; D018570:Risk Assessment; D015813:Substance Abuse Detection
chemical_list: D014150:Antipsychotic Agents