title: Could the Quick Inventory of Depressive Symptomatology-Self-Report (QIDS-SR) be used in depressed schizophrenia patients?
abstract: BACKGROUND
  Developing accurate and time-efficient tools to measure depressive symptoms in schizophrenia is important for research and clinical practice. This study tested the psychometric properties of the Chinese version of the 16-item Quick Inventory of Depressive Symptomatology (QIDS-SR) in depressed schizophrenia patients.
  
  
  METHODS
  This study included 337 clinically stable patients with schizophrenia. The severity of depressive symptoms was assessed using the Montgomery-Asberg Depression Rating Scale (MADRS), QIDS-SR at baseline and 2 weeks later. Negative symptoms and extrapyramidal symptoms were measured with the negative symptom score of Brief Psychiatric Rating Scale (BPRS) and the Simpson-Angus Scale of Extrapyramidal Symptoms (SAS), respectively.
  
  
  RESULTS
  Internal consistency (Cronbach׳s alpha) was 0.73 and 0.67 for QIDS-SR at the baseline and endpoint, respectively. The intra-class correlation coefficient (ICC) for test-retest reliability over the two weeks was 0.77. Two domains (involvement and energy) at baseline and one domain (energy) at endpoint had the highest item-total correlations. The QIDS-SR total score was significantly correlated with the MADRS total score at baseline (r=0.44, p<0.01). Weak correlations of the QIDS-SR score with the scores of the BPRS negative (r=0.18) and the SAS (r=0.05) indicate good discriminant validity. The QIDS-SR showed unidimensional measurement properties in exploratory factor analysis at both baseline. The main limitation of the study is that only clinically stable schizophrenia patients were included.
  
  
  CONCLUSIONS
  The QIDS-SR has acceptable psychometric properties in stable schizophrenia patients and may be useful in both research and clinical practice.
authors.affiliation: Southern Medical University, Guangdong Province, China; Guangdong Mental Health Center, Guangdong General Hospital & Guangdong Academy of Medical Sciences, Guangdong Province, China; Ningxia Mental Health Center, Ningxia Ning-An Hospital, Ningxia Province, China.
authors.forename: Xin-Rong
authors.initials: XR
authors.lastname: Ma
authors.affiliation: Guangdong Mental Health Center, Guangdong General Hospital & Guangdong Academy of Medical Sciences, Guangdong Province, China.
authors.forename: Cai-Lan
authors.initials: CL
authors.lastname: Hou
authors.affiliation: Shenzhen Institute of Mental Health, Shenzhen Kangning Hospital & Shenzhen Mental Health Center, Shenzhen, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zang
authors.affiliation: Guangdong Mental Health Center, Guangdong General Hospital & Guangdong Academy of Medical Sciences, Guangdong Province, China. Electronic address: jiafujun@126.com.
authors.forename: Fu-Jun
authors.initials: FJ
authors.lastname: Jia
authors.affiliation: Guangdong Mental Health Center, Guangdong General Hospital & Guangdong Academy of Medical Sciences, Guangdong Province, China.
authors.forename: Yong-Qiang
authors.initials: YQ
authors.lastname: Lin
authors.affiliation: Department of Psychiatry, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Psychiatry, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Helen F K
authors.initials: HF
authors.lastname: Chiu
authors.affiliation: The University of Notre Dame Australia/Marian Centre, Perth, Australia.
authors.forename: Gabor S
authors.initials: GS
authors.lastname: Ungvari
authors.affiliation: Division of Psychiatry Research, The Zucker Hillside Hospital, North Shore-Long Island Jewish Health System, Glen Oaks, NY, USA.
authors.forename: Christoph U
authors.initials: CU
authors.lastname: Correll
authors.affiliation: Department of Psychiatry, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Kelly Y C
authors.initials: KY
authors.lastname: Lai
authors.affiliation: Department of Psychiatry, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Bao-Liang
authors.initials: BL
authors.lastname: Zhong
authors.affiliation: Department of Psychiatry, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Xiao-Lan
authors.initials: XL
authors.lastname: Cao
authors.affiliation: Guangzhou Yuexiu Center for Disease Control and Prevention, Guangdong Province, China.
authors.forename: Mei-Ying
authors.initials: MY
authors.lastname: Cai
authors.affiliation: Guangzhou Yuexiu Center for Disease Control and Prevention, Guangdong Province, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Yun
authors.affiliation: Faculty of Health Sciences, University of Macau, Macao. Electronic address: xyutly@gmail.com.
authors.forename: Yu-Tao
authors.initials: YT
authors.lastname: Xiang
mesh_terms: D000293:Adolescent; D000328:Adult; D010054:Brief Psychiatric Rating Scale; D002681:China; D003863:Depression / Q000175:diagnosis* / Q000523:psychology*; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D015203:Reproducibility of Results; D012565:Schizophrenic Psychology; D057566:Self Report; D014177:Translations
keywords: Depressive symptoms; Psychometric properties; Quick Inventory of Depressive Symptomatology; Schizophrenia; Self-report