title: Differences in Clinical Features of Methamphetamine Users with Persistent Psychosis and Patients with Schizophrenia.
abstract: BACKGROUND
  Methamphetamine exerts neurotoxic effects and elicits psychotic symptoms. This study attempted to compare clinical differences between methamphetamine users with persistent psychosis (MAP) and patients with schizophrenia. In addition, we examined the discrimination validity by using symptom clusters to differentiate between MAP and schizophrenia.
  
  
  METHODS
  We enrolled 53 MAP patients and 53 patients with schizophrenia. The psychopathology of participants was assessed using the Chinese version of the Diagnostic Interview for Genetic Studies and the 18-item Brief Psychiatric Rating Scale. Logistic regression was used to examine the predicted probability scores of different symptom combinations on discriminating between MAP and schizophrenia. The receiver operating characteristic (ROC) analyses and area under the curve (AUC) were further applied to examine the discrimination validity of the predicted probability scores on differentiating between MAP and schizophrenia.
  
  
  RESULTS
  We found that MAP and schizophrenia demonstrated similar patterns of delusions. Compared to patients with schizophrenia, MAP experienced significantly higher proportions of visual hallucinations and of somatic or tactile hallucinations. However, MAP exhibited significantly lower severity in conceptual disorganization, mannerism/posturing, blunted affect, emotional withdrawal, and motor retardation compared to patients with schizophrenia. The ROC analysis showed that a predicted probability score combining the aforementioned 7 items of symptoms could significantly differentiate between MAP and schizophrenia (AUC = 0.77).
  
  
  CONCLUSIONS
  Findings in the current study suggest that nuanced differences might exist in the clinical presentation of secondary psychosis (MAP) and primary psychosis (schizophrenia). Combining the symptoms as a whole may help with differential diagnosis for MAP and schizophrenia.
authors.affiliation: Department of Child and Adolescent Psychiatry, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan, ROC.
authors.forename: Liang-Jen
authors.initials: LJ
authors.lastname: Wang
authors.forename: Shih-Ku
authors.initials: SK
authors.lastname: Lin
authors.forename: Yi-Chih
authors.initials: YC
authors.lastname: Chen
authors.forename: Ming-Chyi
authors.initials: MC
authors.lastname: Huang
authors.forename: Tzu-Ting
authors.initials: TT
authors.lastname: Chen
authors.forename: Shao-Chun
authors.initials: SC
authors.lastname: Ree
authors.forename: Chih-Ken
authors.initials: CK
authors.lastname: Chen
mesh_terms: D000328:Adult; D010054:Brief Psychiatric Rating Scale; D003702:Delusions / Q000139:chemically induced; D003937:Diagnosis, Differential; D005260:Female; D006212:Hallucinations / Q000139:chemically induced; D006801:Humans; D008297:Male; D008694:Methamphetamine / Q000009:adverse effects*; D008875:Middle Aged; D011605:Psychoses, Substance-Induced / Q000175:diagnosis* / Q000523:psychology; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000523:psychology; D012559:Schizophrenia / Q000139:chemically induced / Q000175:diagnosis*
chemical_list: D008694:Methamphetamine