Study explores association between SSRI use and violent crime

The use of antidepressant SSRIs is modestly associated with violent crime in adolescents and young adults, according to a new study published in the journal PLOS Medicine. The cohort study by researchers from Karolinska Institutet and the University of Oxford showed in subgroup analysis that this association was evident in participants aged 15-24, but not significant for individuals aged 25 and older.

Selective serotonin reuptake inhibitors (SSRI) are widely prescribed, and effectively used to treat for example depression and anxiety syndrome. Inconclusive evidence, however, links SSRI use with violent behaviour. In the current study, Dr Seena Fazel of Oxford University and colleagues compared the rate of violent crime while individuals were prescribed SSRIs with the rate of violent crime in the same individuals while not receiving medication, using matched data from the Swedish Prescribed Drug Register and the Swedish national crime register.

During the 4-year study period (2006-2009), about 850,000 individuals were prescribed SSRIs, and 1% of these individuals were convicted of a violent crime. In age-stratified analysis, associations between SSRI use and convictions for violent crimes were significant for individuals aged 15 to 24 years but not for older individuals. Increased risks were also found in individuals aged 15-24 years for violent arrests, non-violent convictions and arrests, non-fatal accidental injuries and emergency contacts for alcohol-related problems.

Do not prove causation

According to the study-authors, these findings do not prove causation, as possible time-varying confounding by one or more unidentified factors linked to both SSRI use and violent crime may explain the results. Any change to the advice given to young persons prescribed with SSRIs will need to be carefully considered, and should not be based on one study alone.

Lead study-author was Dr Yasmina Molero Samuelson at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet. The research has been funded with grants from the Wellcome Trust, Karolinska Institutet, and the Swedish Research Council. This news article is an edited version of a press release from PLOS Medicine.

• "Study finds young people on antidepressants more prone to violence" – UK Reuters about the findings
• "Depression drugs linked to violence" – news article in The Times
• "Young people on antidepressants more likely to commit violent crime" – The Telegraph

Publication

Selective Serotonin Reuptake Inhibitors and Violent Crime: A Cohort Study
Yasmina Molero, Paul Lichtenstein, Johan Zetterqvist, Clara Hellner Gumpert, Seena Fazel
PLoS Med 12(9): e1001875, online 15 September 2015, doi:10.1371/journal.pmed.1001875