title: Cut points on the Patient Health Questionnaire (PHQ-9) that predict response to cognitive-behavioral treatments for depression.
abstract: OBJECTIVE
  Monitoring depressive symptoms during treatment can guide clinical decision making and improve outcomes. The aim of this study was to explore values on the Patient Health Questionnaire (PHQ-9) that could predict response to treatment.
  
  
  METHODS
  Data came from two independent trials, including three treatment modalities of cognitive-behavioral treatment for depression. Four hundred eighty-seven participants who either met the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition criteria for major depressive disorder or had PHQ-9 scores consistent with a diagnosis of depression were included in our analyses. Participants either received 18 weeks of telephone or face-to-face (n=279) or 8 weeks of Web-delivered (n=208) cognitive-behavioral therapy. Depressive symptoms, evaluated using the PHQ-9, were reported every 4 weeks in the telephone and face-to-face trial and weekly in the Web-delivered intervention trial.
  
  
  RESULTS
  Optimal cut points for predicting end-of-treatment response were consistent in both trials. Our results suggested using cut points of a PHQ-9 ≥17 at Week 4, and PHQ-9 ≥13 at Week 9 and PHQ-9 ≥9 at Week 14.
  
  
  CONCLUSIONS
  Consistent cut points were found within the included trials. These cut points may be valuable for algorithms to support clinical decision making.
authors.affiliation: Northwestern University, Feinberg School of Medicine, Department of Preventive Medicine, 750 N. Lake Shore Drive, 10th Floor, Chicago, IL 60611, United States. Electronic address: Schueller@northwestern.edu.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Schueller
authors.affiliation: Northwestern University, Feinberg School of Medicine, Department of Preventive Medicine, 750 N. Lake Shore Drive, 10th Floor, Chicago, IL 60611, United States. Electronic address: m-kwasny@northwestern.edu.
authors.forename: Mary J
authors.initials: MJ
authors.lastname: Kwasny
authors.affiliation: Macquarie University, Department of Psychology, New South Wales 2109, Australia. Electronic address: blake.dear@mq.edu.au.
authors.forename: Blake F
authors.initials: BF
authors.lastname: Dear
authors.affiliation: Macquarie University, Department of Psychology, New South Wales 2109, Australia. Electronic address: nick.titov@mq.edu.au.
authors.forename: Nickolai
authors.initials: N
authors.lastname: Titov
authors.affiliation: Northwestern University, Feinberg School of Medicine, Department of Preventive Medicine, 750 N. Lake Shore Drive, 10th Floor, Chicago, IL 60611, United States. Electronic address: d-mohr@northwestern.edu.
authors.forename: David C
authors.initials: DC
authors.lastname: Mohr
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015928:Cognitive Behavioral Therapy / Q000379:methods*; D003863:Depression / Q000175:diagnosis / Q000628:therapy*; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011795:Surveys and Questionnaires / Q000592:standards*; D055815:Young Adult
keywords: Cognitive–Behavioral therapy; Computer/Internet technology; Depression; Measurement; Treatment