title: Diagnosis of depression in former injection drug users with chronic hepatitis C.
abstract: OBJECTIVE
  This study seeks to define the performance characteristics of 2 common depression screening tests and how psychiatric diagnoses affect adherence to treatment.
  
  
  BACKGROUND
  Hepatitis C virus is common in former injection drug users (IDU). Many former IDUs have depression, which may complicate treatment, and are often denied therapy.
  
  
  METHODS
  Ninety patients with chronic hepatitis C virus and reported IDU were recruited from a Hepatology Clinic in Seattle. Subjects completed the Beck Depression Inventory (BDI) and Patient Health Questionnaire-9 (PHQ-9) before antiviral therapy. A psychiatrist administered the Mini International Neuropsychiatric Interview as the "gold standard." Adherence was measured by self-report of missed doses.
  
  
  RESULTS
  The BDI and PHQ-9 were highly correlated (r=0.75). Using a BDI score of ≥20 and a PHQ-9 score of ≥10, 39% and 52%, respectively, were misclassified as being depressed, as compared with the Mini International Neuropsychiatric Interview. Maximal sensitivity (85.7%) and specificity (82.6%) was achieved using a BDI score cutoff of 31, with an area under the curve of 0.82. For the PHQ-9, a cutoff of 14 yielded the best sensitivity (85.7%) and specificity (73.9%) with an area under the curve of 0.84. Adherence to at least 80% of medications was achieved by the majority.
  
  
  CONCLUSIONS
  Subjects reported good adherence and outcomes despite a high level of psychiatric comorbidity. The BDI and PHQ-9 were highly correlated but both tended to overdiagnose depression. A high score on BDI or PHQ-9 should not be the sole basis for withholding treatment. These patients should be evaluated by a psychiatrist to make an informed decision.
authors.affiliation: Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98104, USA. jdscott@u.washington.edu
authors.forename: John D
authors.initials: JD
authors.lastname: Scott
authors.forename: Chia C
authors.initials: CC
authors.lastname: Wang
authors.forename: Erica
authors.initials: E
authors.lastname: Coppel
authors.forename: Agnes
authors.initials: A
authors.lastname: Lau
authors.forename: Jason
authors.initials: J
authors.lastname: Veitengruber
authors.forename: Peter
authors.initials: P
authors.lastname: Roy-Byrne
mesh_terms: D000328:Adult; D000928:Antidepressive Agents / Q000627:therapeutic use; D000998:Antiviral Agents / Q000627:therapeutic use; D015897:Comorbidity; D003863:Depression / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D003866:Depressive Disorder / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D005260:Female; D019698:Hepatitis C, Chronic / Q000150:complications* / Q000188:drug therapy / Q000523:psychology; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008403:Mass Screening / Q000379:methods; D055118:Medication Adherence; D008875:Middle Aged; D012307:Risk Factors; D012720:Severity of Illness Index; D015819:Substance Abuse, Intravenous / Q000150:complications*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D000928:Antidepressive Agents; D000998:Antiviral Agents