title: Does major depressive disorder change with age?
abstract: BACKGROUND
  The authors used results from a 20-year, high-intensity follow-up to measure the influence of ageing, and of age at onset, on the long-term persistence of symptoms in major depressive disorder (MDD).
  
  
  METHODS
  Subjects who completed a 20-year series of semi-annual and then annual assessments with a stable diagnosis of MDD or schizo-affective disorder other than mainly schizophrenic (n=220) were divided according to their ages at intake into youngest (18-29 years), middle (30-44 years) and oldest (>45 years) groups. Depressive morbidity was quantified as the proportion of weeks spent in major depressive or schizo-affective episodes. General linear models then tested for effects of time and time x group interactions on these measures. Regression analyses compared the influence of age of onset and of current age.
  
  
  RESULTS
  Analyses revealed no significant time or group x time effects on the proportions of weeks in major depressive episodes in any of the three age groups. Earlier ages of onset were associated with greater symptom persistence, particularly in the youngest group. The proportions of weeks ill showed intra-individual stability over time that was most evident in the oldest group.
  
  
  CONCLUSIONS
  These results indicate that the persistence of depressive symptoms in MDD does not change as individuals move from their third to their fifth decade, from their fourth to their sixth decade, or from their sixth to their eighth decade. An early age of onset, rather than youth per se, is associated with greater morbidity over two decades.
authors.affiliation: Department of Psychiatry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa Hospitals and Clinics, Iowa City, 52242, USA. william-coryell@uiowa.edu
authors.forename: W
authors.initials: W
authors.lastname: Coryell
authors.forename: D
authors.initials: D
authors.lastname: Solomon
authors.forename: A
authors.initials: A
authors.lastname: Leon
authors.forename: J G
authors.initials: JG
authors.lastname: Fiedorowicz
authors.forename: P
authors.initials: P
authors.lastname: Schettler
authors.forename: L
authors.initials: L
authors.lastname: Judd
authors.forename: M
authors.initials: M
authors.lastname: Keller
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000375:Aging / Q000523:psychology; D003865:Major Depressive Disorder / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012737:Sex Factors; D055815:Young Adult