Stability and Outcomes of Suicidal Thoughts and Behavior among Swiss Youths at Ages 13, 16, and 20 Years

Cross-sectional studies have identified concurrent correlates of suicidality among youths. However, longitudinal studies of representative samples are needed to determine the developmental course and outcomes of suicidal thoughts and behavior. To track the course, correlates, and outcomes of suicidality from early adolescence through young adulthood, a team of researchers at the University of Zurich analyzed data obtained in the Zurich Adolescent Psychology and Psychopathology Study (ZAPPS).

Risk for suicide was assessed at three ages in terms of endorsement of at least one of two items concerning suicidal thoughts and behavior on the YSR and the Young Adult Self-Report (YASR), which was the predecessor of the Adult Self-Report (ASR). Youths who endorsed one or both items pertaining to suicide at any of the three assessments were compared with demographically matched control youths who did not endorse either item. At Time 1 (mean age 13 years), 7.6% of the 593 participants endorsed the item pertaining to suicidal thoughts. At Time 2 (mean age 16 years), there was a significant increase to 10.8%. And at Time 3 (mean age 20 years), there was a significant decrease to 7.9%.

A similar trend was found for endorsement of the item pertaining to suicidal behavior, from 2.2%, rising to 3.2%, and declining to 1.7%, although these changes were not statistically significant. Significantly more girls than boys reported suicidal behavior at Times 1 and 2. Classification of youths as being at risk for suicide (i.e., they endorsed at least one YSR/YASR suicide item) vs. not at risk showed significant stability from each assessment to the next assessment(s). At each assessment, youths who were classified as being at risk scored significantly higher than control youths on all YSR/YASR problem scales except the YASR Intrusive scale.

Based on the youths’ responses to separate questionnaires, the following significant psychosocial correlates of suicide risk were found at all three assessments: More total life events; more negative impact of life events; lower self-esteem; higher self-awareness; and more rejection by parents. DSM-IV diagnoses made from the Composite International Diagnostic Interview (CIDI) administered in young adulthood were significantly predicted by the following YSR/YASR scores, after controlling for scores that were similar to the outcome diagnosis: Substance abuse disorders were predicted by Time 1 suicide risk and Externalizing and also by Time 3 Externalizing; depressive disorders were predicted by Time 1 suicide risk and Time 3 Internalizing; phobias were predicted by Time 1 suicide risk and Time 3 Internalizing; and “any diagnosis” was predicted by Time 1 suicide risk and Time 3 Total Problems. Endorsement of one or both YSR suicide items at age 13 was thus a significant predictor of all four categories of DSM-IV diagnoses 7 years later, at age 20. 

Reference: Steinhausen, H-C., Bösiger, R., & Winkler Metzke, C. (2006). Stability, correlates, and outcome of adolescent suicidal risk. Journal of Child Psychology and Psychiatry, 47, 713-722.