The study measured only the extremely severe outcome of violent crime convictions, so the risk of increased aggressive behavior, in general, is likely much higher.
The published, peer-reviewed version of this study was previously reported on at Mad in America. However, a report on Medscape on September 21 detailed further results presented at the 33rd European College of Neuropsychopharmacology (ECNP) Congress. Researcher Tyra Lagerberg led the study at the Karolinska Institutet, Stockholm, Sweden.
The researchers analyzed their results in several ways.
First, when stratifying by age, the researchers found that all ages experienced a significantly increased risk of violent crime while taking the drugs except the 35- to 44-year-old cohort. The risk was 28% higher when on SSRIs for 15- to 24-year-olds, 35% higher for 25- to 34-year-olds, non-significant for 35- to 44-year-olds, and 25% higher for 45- to 60-year-olds.
Second, the researchers did a different kind of analysis where they pooled all-time on the drugs versus all the time off the drugs (as opposed to the individually controlled analysis). Using this method, the risk of violent crime conviction fell to a 10% increase. However, this type of analysis doesn’t control for individual differences—which the first type does.
Third, the researchers wanted to determine if the risk was increased immediately after starting an antidepressant. They theorized that the SSRI could increase motivation or energy and prompt aggression early in the treatment, but then stabilize. In fact, Lagerberg and co-authors presented this as a possible explanation in their published journal article.
However, according to Medscape, they were wrong—their results showed that the risk of increased violent crime conviction was stable throughout the course of antidepressant treatment. Medscape quotes Lagerberg as saying, “In our cases, we don’t see such an effect for violent crime.”
They also found that the risk increased to 37% just after discontinuing the drug (in the first 28 days after stopping treatment). The risk fell to non-significance once it had been at least 84 days since taking the drug. This finding would be expected with withdrawal effects, rather than a relapse of “mental illness,” since the risk increased immediately after stopping the drug, then stabilized once the person was off the drug for a period of time.
The researchers take care to downplay these results. Medscape quotes Lagerberg as saying that “the risk for violent crime among those taking SSRIs is ‘very, very rare, and doctors should only really talk to people [about it] who’ve had a history of this outcome before.’”
Medscape also includes an interview with Georgia Hodes, Ph.D., an assistant professor at Icahn School of Medicine at Mount Sinai, New York City. Hodes is quoted as saying, “the study makes it clear that the risk for violent crime is small and is likely to only be found in ‘a subset of people who may have some issue with serotonin levels to begin with.’”
Notably, the researchers did not measure serotonin levels, so it is unclear how Hodes came to that conclusion.
The current study is consistent with previous research, which has found that antidepressant use increases violent crime in youth and is associated with more violent means for suicide attempts. Other researchers have also written that antidepressants cause violence and suicide attempts. This could be due to antidepressant-induced akathisia, a state of extreme agitation, and restlessness linked to aggression and suicide.
Read the Medscape report here: https://www.medscape.com/viewarticle/937766