title: Validity of a simpler definition of major depressive disorder.
abstract: BACKGROUND
  In previous reports from the Rhode Island Methods to Improve Diagnostic Assessment and Services project, we developed a briefer definition of major depressive disorder (MDD), and found high levels of agreement between the simplified and DSM-IV definitions of MDD. The goal of the present study was to examine the validity of the simpler definition of MDD. We hypothesized that compared to patients with adjustment disorder, patients with MDD would be more severely depressed, have poorer psychosocial functioning, have greater suicidal ideation at the time of the intake evaluation, and have an increased morbid risk for depression in their first-degree family members.
  
  
  METHODS
  We compared 1,486 patients who met the symptom criteria for current MDD according to either DSM-IV or the simpler definition to 145 patients with a current diagnosis of adjustment disorder with depressed mood or depressed and anxious mood.
  
  
  RESULTS
  The patients with MDD were more severely depressed, more likely to have missed time from work due to psychiatric reasons, reported higher levels of suicidal ideation, and had a significantly higher morbid risk for depression in their first-degree family members. Both definitions of MDD were valid.
  
  
  CONCLUSIONS
  The simpler definition of MDD was as valid as the DSM-IV definition. This new definition offers two advantages over the DSM-IV definition-it is briefer and therefore more likely to be recalled and applied in clinical practice, and it is free of somatic symptoms thereby making it easier to apply with medically ill patients.
authors.affiliation: The Department of Psychiatry and Human Behavior, Rhode Island Hospital, Brown Medical School, Providence, USA. mzimmerman@lifespan.org
authors.forename: Mark
authors.initials: M
authors.lastname: Zimmerman
authors.forename: Janine N
authors.initials: JN
authors.lastname: Galione
authors.forename: Iwona
authors.initials: I
authors.lastname: Chelminski
authors.forename: Diane
authors.initials: D
authors.lastname: Young
authors.forename: Kristy
authors.initials: K
authors.lastname: Dalrymple
authors.forename: Caren Francione
authors.initials: CF
authors.lastname: Witt
mesh_terms: D000275:Adjustment Disorders / Q000175:diagnosis / Q000523:psychology; D000553:Ambulatory Care; D003865:Major Depressive Disorder / Q000145:classification / Q000175:diagnosis* / Q000523:psychology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D007406:Interview, Psychological / Q000379:methods; D008297:Male; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D015203:Reproducibility of Results; D012237:Rhode Island; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012959:Socioeconomic Factors; D059020:Suicidal Ideation; D009626:Terminology as Topic