title: Crowding and violence on psychiatric wards: explanatory models.
abstract: OBJECTIVE
  Violence is widely prevalent on acute-care psychiatric wards, and crowding has been identified as a major risk factor. This paper explores why patients may respond to crowding with violence.
  
  
  METHODS
  We carried out a literature review on Medline, using the key words "violence" and "crowding." We conducted an additional hand search of the references collected from the reviewed papers.
  
  
  RESULTS
  Factors specific to the relation between crowding on acute-care inpatient psychiatric wards and violence can be divided under the following headings: 1) patient density, privacy, and control; 2) ward architecture; 3) the social organization of psychiatric wards; 4) interpersonal space; 5) phylogenic theories; and 6) anthropological theories of human behaviour.
  
  
  CONCLUSIONS
  We offer explanatory models for this relation and suggest strategies to counter the effects of crowding. Recommendations are made for future studies.
authors.affiliation: Department of Psychiatry, Rotorua Hospital, Rotorua, New Zealand. kumars@lhl.co.nz
authors.forename: S
authors.initials: S
authors.lastname: Kumar
authors.forename: B
authors.initials: B
authors.lastname: Ng
mesh_terms: D003441:Crowding / Q000523:psychology*; D006801:Humans; D011567:Psychiatric Department, Hospital; D011582:Psychological Theory; D012307:Risk Factors; D012931:Social Environment; D014754:Violence / Q000523:psychology* / Q000706:statistics & numerical data