Ongoing university studies and the risk of suicide: A registration-based nationwide cohort study of 5 million young and middle-aged individuals in Sweden, 1993-2011.

Objectives To investigate the risk of suicide, unnatural death and all-cause death in university students compared with non-students, taking previous educational attainment into account.

Design Open cohort study of all residents aged 18–39 and living in Sweden at any time between 1 January 1993 and 31 December 2011.

Setting We linked data from national registers and calculated person-years during university studies for three time periods (1993–1999, 2000–2005 and 2006–2011). Time as non-student was calculated and categorised according to attained educational level. Incidence rate ratios (IRR) with 95% CIs were calculated with Poisson regression models, controlling for age and period.

Participants The cohort consisted of 5 039 419 individuals, 51% men and 49% women.

Main outcome measures Incidence of suicide (International Classification of Diseases (ICD)-9: E950–E959, ICD-10: X60–X84) or death with undetermined intent (ICD-9: E980-E989, ICD-10: Y10-Y34), unnatural death (ICD-9: E800-E999 and ICD-10: V01-Y99) and all-cause death.

Results A total of 7316 deaths due to suicide were identified, of which 541 were registered among university students. The risk of suicide was twofold during ongoing university studies compared with when having attained university education, IRR 2.37 (95% CI 2.07 to 2.72) in men and IRR 2.15 (95% CI 1.77 to 2.61) in women.

Conclusions Having ongoing university studies was associated with a higher risk of suicide compared with having attained university-level education. This finding highlights the importance of achieving a deeper understanding of suicidal behaviour during years at university. Further studies should assess risk factors for suicide and suicidal behaviour in university students.