Widening disparities in all-cause and despair-related mortality among Swedish youths: Disentangling selection and causation.

Rising rates of "deaths of despair" - mortality from suicide, drug overdose, and alcohol-related causes - have contributed to widening educational disparities in mortality. It is not known to what extent the trends are due to selection effects (health causing education, or a third factor causing both) or social causation (education affecting health). This study investigated the relative contribution of selection and causation for these trends, focusing on the recently documented widening achievement-based disparities in mortality among Swedish youths. To this end, two cohorts of Swedish compulsory school graduates (graduating in 1992-1993 and 2009-2010, respectively) were followed for eight years after graduation using comprehensive administrative data (n = 424,715). Logistic regression models were used to assess the role of pre-graduation selection, while inverse odds ratio-weighting was used to assess mediation by post-graduation socioeconomic disadvantages. Roughly half of the association between low achievement and all-cause and despair-related mortality within cohorts was due to selection. However, selection effects did not explain the widening disparities over time. Socioeconomic mediators accounted for most of the remaining disparities within cohorts as well as of for most of the increase in these disparities over time. Overall, social causation was more important than selection in explaining the widening educational disparities in all-cause and despair-related mortality. We conclude that low academic achievement increasingly constrains life-course prospects of Swedish youths, amplifying its adverse health consequences. These findings highlight the need for lower barriers in the education system and for viable educational and employment pathways for low-achieving students in an increasingly knowledge-intensive labor market.