title: Pain perception in patients with bipolar disorder and schizophrenia.
abstract: OBJECTIVE
  Pain perception is reported to be altered in patients with depression and schizophrenia. However, few studies have investigated the pain perception in patients with bipolar disorders. We therefore aimed to compare pain sensitivity between patients with bipolar disorder, schizophrenia and controls.
  
  
  METHODS
  Study groups consisted of 30 patients with bipolar disorder, and control groups consisted of 27 patients with schizophrenia and 59 healthy subjects. Pain perception was assessed with cold pressor test (CPT) by exposure to ice-water.
  
  
  RESULTS
  Patients with schizophrenia had significantly higher pain thresholds (PTh) than patients with bipolar disorder. There were no differences between the PTh of patients with schizophrenia and healthy control subjects. However, patients with bipolar disorder had significantly lower pain tolerance (PT) in the CPT than patients with schizophrenia and corresponding healthy control subjects.
  
  
  CONCLUSIONS
  The higher PTh in the schizophrenia group compared with the bipolar group found in this study supports further investigation of a potential difference in the pain perception between patients with schizophrenia and bipolar disorder. Theoretical implications of these findings and possible relevant behavioural and neurochemical mechanisms are discussed.
authors.affiliation: 1Zon guldak Karaelmas University, Faculty of Medicine, Department of Psychiatry, Zonguldak, Turkey.
authors.forename: Levent
authors.initials: L
authors.lastname: Atik
authors.affiliation: 1Zon guldak Karaelmas University, Faculty of Medicine, Department of Psychiatry, Zonguldak, Turkey.
authors.forename: Numan
authors.initials: N
authors.lastname: Konuk
authors.affiliation: 1Zon guldak Karaelmas University, Faculty of Medicine, Department of Psychiatry, Zonguldak, Turkey.
authors.forename: Omer
authors.initials: O
authors.lastname: Akay
authors.affiliation: 1Zon guldak Karaelmas University, Faculty of Medicine, Department of Psychiatry, Zonguldak, Turkey.
authors.forename: Devrim
authors.initials: D
authors.lastname: Ozturk
authors.affiliation: 1Zon guldak Karaelmas University, Faculty of Medicine, Department of Psychiatry, Zonguldak, Turkey.
authors.forename: Ayten
authors.initials: A
authors.lastname: Erdogan