Abstract

Background: Suicide is a leading cause of death in young adults. Several risk factors are well known, especially those related to adult mental health. However, some risk factors may have their origin in the very beginning of life. This study examines suicide in the general Norwegian population in a life course perspective, with a main focus on early life factors.

Methods: We linked several national registers, supplying personal data on biological and social variables from childhood to young adult age. Participants were all Norwegians live born during the period 1967-1976, followed up through 2004. Persons who died or emigrated before the year of their 19th birthday, at which age follow-up started, were excluded. Thus, the study population comprised 610 359 persons, and the study outcome was completed suicide.

Results: 1406 suicides (0.23%) were recorded, the risk being four times higher in males than in females. Suicide risk factors included: not being first born (adjusted HR in males and females (95% confidence intervals): 1.19 (1.05 to 1.36) and 1.42 (1.08 to 1.88)), instability of maternal marital status during childhood, parental suicide (mainly in females), low BMI (only investigated in males), low education, and indications of severe mental illness.

Conclusions: Suicide in young adults may be rooted in early childhood, and the effect is likely to act through several mechanisms, some of which may be linked to the composition and stability of the parental home. A life course perspective may add to our understanding of suicide.