What is the association between antidepressants and violent behavior?

The recent news of a Germanwings pilot with depression who appeared to commit murder-suicide has people wondering about what could cause this. All we know from news reports is that he was treated for “suicidal tendencies,” and received psychotherapy, or counseling. But nothing has been reported about whether he took antidepressant medication. It’s a valid question, as depression, especially more severe cases of depression, are usually treated with antidepressant medication.

Over the last decade, there seems to be an understanding amongst the general public that antidepressants could be a causal factor for violent behavior perpetrated to others. This understanding has been fueled by the media, case reports, and a few experts who have come to the revelation that antidepressants cause violence to others, which includes physical assault, homicide, and homicidal ideations. Pop psychologists may weigh in on this question, but these experts who scare the public with their revelations of antidepressant-induced murder rampages are doing an excellent job of that…scaring the public.

But what do the studies show regarding this association between antidepressants and murder, and murder-suicides? There are not many studies to assess this association, but there are two relatively recent studies that can help us answer this question:

Moore and colleagues (2010) looked at prescription drugs that were reported to the U.S. FDA (Food and Drug Administration) from 2004 to 2009 with serious adverse events that included physical assault, homicide, and homicidal ideations. They found that antidepressants with effects on serotonin and varenicline (for smoking cessation) were most associated with violence. However, the authors have a bias, as they have been retained as expert witnesses for court cases involving antidepressants.

Bouvy and Liem (2012) looked at nationwide data in the Netherlands on antidepressant prescriptions from 1994 to 2008, and also looked at lethal violence. What they found was that as antidepressant prescription exposure increased, the rate of lethal violence decreased. This is in opposition to the Moore study. Additionally, Bouvy and Liem had no disclosed conflicts of interest.

So which study are you to believe? What these conflicting studies tell us is that the jury is still out on this association of antidepressants and violence. So how should this inform how antidepressants are prescribed? Well, it should tell you that antidepressants should be prescribed and monitored carefully, and not given out like candy. You should be monitored closely by your prescribing doctor, as there are side effects from antidepressants that can lead to violence:

• Activation
  Antidepressants can cause stimulation or agitation, especially when first starting it.
• Manic switching
  If you have a predisposition to manic-depression, also known as bipolar disorder, then starting an antidepressant alone can trigger a manic episode.
• Increase in suicidal ideations
  Antidepressants can increase suicidal ideations and behaviors in children, adolescents, and young adults (below age 25) (Stone et al., 2009).
• Your thoughts are the last thing to change
  Antidepressants will initially help you to increase energy and improve concentration. Your thoughts, however, will not change until later. So if you have increased energy and concentration, then you might carry out and act on your thoughts.

In summary, there are conflicting studies about the association of antidepressant medications and violence. However, as the jury is still out, it is prudent to take antidepressants with extreme caution, and to get close monitoring by your doctor. Treatment-emergent side effect of antidepressants which can contribute to violence include activation (stimulation and agitation), manic switching, increase in suicide in people under age 25 years, and having the energy and concentration to act on your thoughts.