title: Does age at onset of first major depressive episode indicate the subtype of major depressive disorder?: the clinical research center for depression study.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effects of age at onset of the first major depressive episode on the clinical features of individuals with major depressive disorder (MDD) in a large cohort of Korean depressed patients.
  
  
  METHODS
  We recruited 419 MDD patients of age over 18 years from the Clinical Research Center for Depression study in South Korea. At the start of the study, the onset age of the first major depressive episode was self-reported by the subjects. The subjects were divided into four age-at-onset subgroups: childhood and adolescent onset (ages <18), early adult onset (ages 18-44), middle adult onset (ages 45-59), and late onset (ages 60+). Using analysis of covariance (ANCOVA) and ordinal logistic regression analysis with adjusting the effect of age, the relationships between clinical features and age at onset of MDD were evaluated.
  
  
  RESULTS
  There was an apparent, but inconsistent correlation between clinical features and age at onset. Earlier onset MDD was significantly associated with higher proportion of female gender [adjusted odds ratio (AOR)=0.570, p=0.022], more previous suicide attempts (AOR=0.635, p=0.038), greater number of previous depressive episodes (F=3.475, p=0.016) and higher scores on the brief psychiatric rating scale (F=3.254, p=0.022), its negative symptom subscale (F=6.082, p<0.0001), and the alcohol use disorder identification test (F=7.061, p<0.0001).
  
  
  CONCLUSIONS
  Early age at onset may increase the likelihood of distinguishable MDD subtype, and age at onset of the first major depressive episode is a promising clinical indicator for the clinical presentation, course, and outcome of MDD.
authors.affiliation: Department of Psychiatry, Yong-In Mental Hospital, Yongin, Korea.; Institute of Mental Health, Hanyang University, Seoul, Korea.
authors.forename: Seon-Cheol
authors.initials: SC
authors.lastname: Park
authors.affiliation: Department of Psychiatry, College of Medicine, Soonchunhyang Univeristy, Seoul Hospital, Seoul, Korea.
authors.forename: Sang-Woo
authors.initials: SW
authors.lastname: Hahn
authors.affiliation: Department of Psychiatry, Yong-In Mental Hospital, Yongin, Korea.; WHO Collaborating Center for PR and CMH, Yong-In Mental Hospital, Yongin, Korea.
authors.forename: Tae-Yeon
authors.initials: TY
authors.lastname: Hwang
authors.affiliation: Department of Psychiatry, School of Medicine, Chonnam National University, Gwangju, Korea.
authors.forename: Jae-Min
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Psychiatry, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Tae-Youn
authors.initials: TY
authors.lastname: Jun
authors.affiliation: Department of Psychiatry, College of Medicine, Korea University, Seoul, Korea.
authors.forename: Min-Soo
authors.initials: MS
authors.lastname: Lee
authors.affiliation: Department of Psychiatry, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Jung-Bum
authors.initials: JB
authors.lastname: Kim
authors.affiliation: Department of Preventive Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Hyeon-Woo
authors.initials: HW
authors.lastname: Yim
authors.affiliation: Institute of Mental Health, Hanyang University, Seoul, Korea.; Department of Psychiatry, College of Medicine, Hanyang University, Guri Hospital, Guri, Korea. hypyc@hanyang.ac.kr.
authors.forename: Yong Chon
authors.initials: YC
authors.lastname: Park
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D017668:Age of Onset; D000368:Aged; D003863:Depression / Q000453:epidemiology; D003865:Major Depressive Disorder / Q000145:classification* / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D006801:Humans; D008016:Life Change Events; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis; D056910:Republic of Korea; D013406:Suicide, Attempted / Q000523:psychology; D055815:Young Adult
keywords: Major depressive disorder; age at onset; clinical indicator; subtype