Major depressive disorder in adolescence: the role of subthreshold symptoms.
OBJECTIVE
To examine the longitudinal association between individual subthreshold symptoms and onset of major depressive disorder (MDD) in adolescence.


METHODS
Data for analysis come from the Oregon Adolescent Depression Project, a prospective epidemiological study of psychological disorders among adolescents, ages 14 to 18 years, from the general community. A total of 1,709 adolescents completed the initial diagnostic assessments between 1987 and 1989 (T1) and approximately 1 year later (T2), 1,507 adolescents returned for readministration of assessments (88% response).


RESULTS
After controlling for history of depression and gender, seven of the nine DSM-III-R symptoms of depression predicted MDD incidence when tested in separate models. Endorsement of each symptom at T1 increased the likelihood of MDD incidence between T1 and T2. A summary model that included the seven DSM-III-R symptoms as predictors was significant, with sad mood contributing unique variance to the prediction of MDD onset (odds ratio = 2.01).


CONCLUSIONS
These findings suggest that much of the variance is shared among symptom predictors and the co-occurrence of symptoms is what constitutes the greatest risk. Moreover, the presence of sad mood contributes additional unique variance to prediction and supports the centrality of depressed mood to MDD.
Georgiades
Katholiki
K
Dr. Georgiades is with the Offord Centre for Child Studies and the Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada; Drs. Lewinsohn and Seeley are with the Oregon Research Institute, Eugene; and Dr. Monroe is with the Department of Psychology, University of Oregon, Eugene.. Electronic address: georgik@mcmaster.ca.
Lewinsohn
Peter M
PM
Dr. Georgiades is with the Offord Centre for Child Studies and the Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada; Drs. Lewinsohn and Seeley are with the Oregon Research Institute, Eugene; and Dr. Monroe is with the Department of Psychology, University of Oregon, Eugene.
Monroe
Scott M
SM
Dr. Georgiades is with the Offord Centre for Child Studies and the Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada; Drs. Lewinsohn and Seeley are with the Oregon Research Institute, Eugene; and Dr. Monroe is with the Department of Psychology, University of Oregon, Eugene.
Seeley
John R
JR
Dr. Georgiades is with the Offord Centre for Child Studies and the Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada; Drs. Lewinsohn and Seeley are with the Oregon Research Institute, Eugene; and Dr. Monroe is with the Department of Psychology, University of Oregon, Eugene.
D000293:Adolescent; D003710:Demography; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires