Adverse life events, psychiatric morbidity, and mortality : epidemiological studies of socioeconomic inequalities from a life course perspective

The overall aim with this dissertation was to increase the knowledge on the association between adverse life events, and psychiatric morbidity and mortality, and the role of socioeconomic position from a life course perspective.

In Study I we examined the association between socioeconomic position, adverse childhood experiences, and psychotropic medication in young adulthood, using parental educational level as measure of socioeconomic position. A cohort of 362 663 individuals born in Sweden between 1985 and 1988 was followed from birth until 2008. Adverse childhood experiences were associated in a dose-response manner with increased risks of psychotropic medication. This relationship was similar in all socioeconomic groups.

In Study II we examined whether juvenile delinquency, defined as being convicted of a crime between the ages of 15 and 19, increased the risk of suicide in young adulthood. Nearly one million individuals were included. We found an increased risk of suicide in juvenile delinquents, where the highest suicide risk was found in repeated juvenile offenders.

In Study III we examined if divorce was associated with an increased risk of psychiatric morbidity. All married or divorced residents in Sweden between the ages of 45 and 54 in 2006, with no history of psychiatric care 1987–2005 were included (n=703 960). Psychiatric morbidity was defined as psychiatric inpatient care, outpatient care and use of psychotropic medication. Divorced women and men had a higher risk for psychiatric inpatient care compared to married. The longer the marriages the lower the risk for psychiatric morbidity. Lower educational level increased the risk for psychiatric inpatient care after divorce.

In Study IV we compared overall and cause-specific mortality and quality of somatic care among psychiatric patients and non-psychiatric patients. All individuals between the ages of 20 and 79 in 2005 (n=6 294 339) were followed with respect to mortality in 2006 and 2007. Psychiatric patients had a substantially increased risk of all studied causes of death as well as death from conditions considered amenable to intervention by the health service, i.e. avoidable mortality. The analysis of the quality of somatic care revealed lower levels of health care quality for psychiatric patients, signaling failures in medical care.

In conclusion, individuals who have experienced adverse life events have a higher prevalence of psychiatric morbidity than those who have not. This increased psychiatric morbidity was observed regardless of whether the adverse life event occurred in childhood, adolescence or in middle age. Adverse life events were more common among individuals in lower socioeconomic groups, and socioeconomic position tended to modify the relationship between adverse life events and psychiatric morbidity.

List of scientific papers

I. Björkenstam E, Hjern A, Mittendorfer-Rutz E, Vinnerljung B, Hallqvist J, Ljung R. Multi-exposure and clustering of adverse childhood experiences, socioeconomic differences and psychotropic medication in young adults. PLoS One. 2013;8(1):e53551. Epub 2013 Jan 16.
https://doi.org/10.1371/journal.pone.0053551

II. Björkenstam E, Björkenstam C, Vinnerljung B, Hallqvist J, Ljung R. Juvenile delinquency, social background and suicide--a Swedish national cohort study of 992,881 young adults. International Journal of Epidemiology. 2011 Dec;40(6):1585-92.
https://doi.org/10.1093/ije/dyr127

III. Björkenstam E, Hallqvist J, Dalman C, Ljung R. Risk of new psychiatric episodes in the year following divorce in midlife: Cause or selection? A nationwide register-based study of 703,960 individuals. International Journal of Social Psychiatry. 2012 Oct 15.
https://doi.org/10.1177/0020764012461213

IV. Björkenstam E, Ljung R, Burström B, Mittendorfer-Rutz E, Hallqvist J, Weitoft GR. Quality of medical care and excess mortality in psychiatric patients--a nationwide register-based study in Sweden. BMJ Open. 2012 Feb 24;2:e000778.
https://doi.org/10.1136/bmjopen-2011-000778