title: Early- versus late-onset dythymic disorder: comparison in out-patients with superimposed major depressive episodes.
abstract: BACKGROUND
  This study examined the validity of the early-late onset subtyping distinction in dysthymic disorder.
  
  
  METHODS
  Participants were 340 out-patients meeting DSM-III-R criteria for dysthymia and a concurrent major depressive episode (MDE). The sample was drawn from a 12-site double-blind randomized parallel group trial comparing the efficacy of sertraline and imipramine in the treatment of chronic depression. All patients received comprehensive evaluations using semi-structured interviews and rating scales.
  
  
  RESULTS
  73% of the sample met criteria for the early-onset, and 27% for the late-onset, subtype. The early-onset patients had a significantly longer index MDE, significantly higher rates of personality disorders and lifetime substance use disorders, and a significantly greater proportion had a family history of mood disorder. The subgroups did not differ in symptom severity or functional impairment at baseline, nor in response to a 12-week trial of antidepressants.
  
  
  CONCLUSIONS
  Further work is needed to extend these findings to dysthymic disorder without superimposed MDEs.
  
  
  CONCLUSIONS
  These results support the distinction between early-onset and late-onset dysthymic disorder.
authors.affiliation: Department of Psychology, State University of New York at Stony Brook, 11794-2500, USA. dklein@ccvm.sunysb.edu
authors.forename: D N
authors.initials: DN
authors.lastname: Klein
authors.forename: A F
authors.initials: AF
authors.lastname: Schatzberg
authors.forename: J P
authors.initials: JP
authors.lastname: McCullough
authors.forename: M B
authors.initials: MB
authors.lastname: Keller
authors.forename: F
authors.initials: F
authors.lastname: Dowling
authors.forename: D
authors.initials: D
authors.lastname: Goodman
authors.forename: R H
authors.initials: RH
authors.lastname: Howland
authors.forename: J C
authors.initials: JC
authors.lastname: Markowitz
authors.forename: C
authors.initials: C
authors.lastname: Smith
authors.forename: R
authors.initials: R
authors.lastname: Miceli
authors.forename: W M
authors.initials: WM
authors.lastname: Harrison
mesh_terms: D000328:Adult; D000553:Ambulatory Care; D000704:Analysis of Variance; D000929:Antidepressive Agents, Tricyclic / Q000627:therapeutic use; D002908:Chronic Disease; D003865:Major Depressive Disorder / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D004311:Double-Blind Method; D019263:Dysthymic Disorder / Q000150:complications* / Q000175:diagnosis; D005260:Female; D006801:Humans; D007099:Imipramine / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D017367:Selective Serotonin Reuptake Inhibitors / Q000627:therapeutic use; D020280:Sertraline / Q000627:therapeutic use; D012720:Severity of Illness Index
chemical_list: D000929:Antidepressive Agents, Tricyclic; D007099:Imipramine; D017367:Selective Serotonin Reuptake Inhibitors; D020280:Sertraline