STOCKHOLM, Sweden — Selective serotonin reuptake inhibitors (SSRIs) are some of the most widely prescribed antidepressant drugs in the world. Now, an unsettling new study out of Sweden finds that some people given these medications develop a “tendency” to commit violent crimes. According to the research, this violent effect can even last for up to 12 weeks after halting SSRI treatment.
To be clear, the study’s authors emphasize that their work detected an association between SSRIs and violent behavior, not a clear-cut case of cause and effect. They warn that their findings should not be used to draw any definitive conclusions.
“This work shows that SSRI (selective serotonin reuptake inhibitor) treatment appears to be associated with an increased risk for violent criminality in adults as well as adolescents, though the risk appears restricted to a small group of individuals,” notes first author Tyra Lagerberg, from the Department of Medical Epidemiology and Biostatistics at the Karolinska Institutet, in a statement. “We don’t claim that SSRIs cause the increased risk we see in our data. It is possible that the disorders that SSRIs are prescribed to treat, such as depression, are driving the association. In that case our findings may mean that SSRIs are unable to fully remove this tendency towards violent crime, which is also a potentially important insight.”
Lagerberg says earlier studies have made the connection between the drugs and violent behavior in youths, but this latest and larger work is the first to draw a link to adults. Age didn’t seem to make a difference in the outcome.
A massive dataset was analyzed for this research. The medical records of 785,337 people between the ages of 15 and 60 who had been prescribed SSRIs in Sweden between 2006 and 2013. All of those patients were tracked for an average of seven years, regardless of whether or not they continued taking SSRIs.
In all, it was noted that studied patients had committed 6,306 violent crimes while taking SSRIs and 25,897 while not taking them. While that doesn’t seem like much of a correlation at first, after accounting for follow-up time and other variables related to the probability of SSRI treatment and individual risk for committing violence, researchers concluded that taking SSRIs resulted in an average 26% increase in one’s odds of committing a violent crime.
All that being said, only 2.7% of all studied participants went on to commit any violent acts. So, researchers say that SSRIs only appear to foster violent behavior in a very small percentage of patients.
“Previous studies have shown that depression itself is associated with a 3-fold increase in the risk for violent crime, and of course many SSRIs are prescribed for depression; so it may be the underlying depression that causes the association with violent crime, rather than any effect of the SSRI. More work is needed to uncover the causes of this association,” Lagerberg explains.
Still, the authors note that 97% of those studied showed no indication of violent behavior.
“Our findings do not affect the vast majority of people taking antidepressants and should not be used as basis for individuals to stop their SSRI treatment, nor for prescribers to withhold treatment from individuals who might benefit from it,” says Lagerberg. “Nevertheless, clinicians should be attentive when prescribing SSRIs to individuals with aggressive tendencies.”
Moving forward, more research is needed to identify any specific traits that could suggest those who take SSRIs would be more likely to commit a crime.
“The study also shows that past offenders were more likely to commit a violent crime during SSRI treatment: this in itself is an interesting finding, which could be the main focus of future research on the topic,” concludes lead author Professor Eduard Vieta.
The study is published in European Neuropsychopharmacology.