Objective: To examine the role of depressive symptoms and disorders as associates and predictors of suicidal acts across adolescence.
Method: A representative sample of Norwegian school students (N = 2464, mean age 13.7 years) in grades 8 and 9 was reassessed after one year (T2) with the same questionnaire. All high scorers of depressive symptoms on the Mood and Feelings Questionnaire (MFQ) at T2 were defined as cases. One control from low or middle scorers, matched for age and gender, was randomly assigned to every two cases. This subset (n = 345) was diagnostically assessed by face-to-face K-SADS-PL interviews (mean age = 14.9 years). The same subset was reassessed after 5 years (T3) by using the same questionnaire (n = 252, mean age = 20.0 years) and telephone K-SADS-PL interviews (n = 242). The participation rate was 76.9% (n = 265).
Results: Cognitive symptoms dominated the depressive symptom profile among suicide attempters, irrespective of age and time. Among younger adolescents, suicidal thoughts and acts of self-harm without suicidal intent were associated with suicidal acts. Recurrent thoughts about death, hopelessness, disturbed concentration and middle insomnia were associates of suicidal acts among older adolescents. Worthlessness by 15 years was a significant predictor of suicidal acts between 15 to 20 years. MDD and a depressive episode, not otherwise specified, continued to be significant associates among younger adolescents, while dysthymia by 15 years remained a predictor of suicidal acts between 15 to 20 years, even when controlled for depressive symptoms.
Conclusions: Self-harm without suicidal intent, middle insomnia, cognitive depressive symptoms and a formal psychiatric diagnosis of any depressive disorder should alert professionals in the risk assessment of suicidal adolescents.