SSRIs, Violence, Walking, and Dogs

Recently a link was making the rounds on Tumblr about how SSRI anti-depressants caused violent and homicidal reactions in people (h/t to the lovely Cara for making sure we saw it). I was largely ignoring it because, frankly, there’s a lot of unproductive discussions about whether SSRIs, or anti-depressants in general, or even psychotropic drugs as a whole, are teh most awesome things ever! or an evil tool of big pharma or poisoning our children or should be put in the water supply to help the population at large. And my attitude towards psych treatment, whether it be therapy or medication or anything else, is pretty similar to my attitude about religion: everyone has the right to make their own determinations about their treatment and whether they would or would not like to take psych meds, and just as my atheism doesn’t make someone else’s faith any less valid, I can support someone’s decision to reject psych meds without lessening my own right to believe they help me personally. (To extend that, I support anyone’s right and decision to pursue or not pursue any kind of treatment, to identify as they feel appropriate, and to reject the whole framework and basis of psychiatry.)

That said, I thought it might be useful to take a look at this article to discuss some of the issues I see in a lot of these arguments and discussions. The basic gist of the article is to publicize an archive of “3,500 crime related news reports linked to the use of SSRI antidepressants … Pharma and the FDA may still be agnostic about SSRIs causing violence but 700 murders, 200 murder-suicides and 47 postpartum depression cases, including the 2006 case of Andrea Yates who drowned her five children on Effexor, don’t lie.” The article describes the site as “more of a public service than the FDA which has yet to withdraw the drugs named in the 3,500 stories–or even call them dangerous,” so the clear goal of the article is to encourage prohibition of SSRIs as a class.

That’s a pretty broad goal to be supported by such thin and unconvincing evidence – and that’s my problem with these kinds of arguments. Whenever I talk about these kinds of science articles, I often use the same phrase: “correlation does not equal causation.” This means that although two variables may be very closely associated, there’s not enough information to figure out which of them causes the other, or even if the two are related by anything more than chance and coincidence. A simple example is that everyone who orders food at McDonald’s is a human. Can we assume that if a dog walked into McDonald’s and ordered food, it would magically transform into a human because of the correlation between ordering at McDonald’s and being human? No.

To unpack this further, let’s look at the fact that a lot of people who walk in my neighborhood have dogs. I know some people who got dogs specifically in order to encourage themselves to do more walking – so the dog is influencing how often they walk. However, I also know people who do a lot of running or hiking and got a dog to keep them company on their outings – so their walking/running influenced their having a dog. So does being a person who walks outdoors make you more likely to get a dog, or does having a dog make you more likely to walk outdoors? We just do not have enough information to figure that out. This means my observations of walkers and dogs should not justify a public policy to issue dogs to every household to ensure people walk outdoors.

To extend this to the SSRI stories, there’s not enough evidence for us to determine if people who are not violent or homicidal become so when they are given SSRIs, or whether people who are already violent or homicidal are likely to be given SSRIs for treatment. And that’s a very important thing to be absolutely clear on when we’re talking about having the FDA eliminate an entire class of anti-depressants that some (including me) rely on for treatment.

There’s a couple other factors in the dog analogy that I also see at play in this SSRI story:

  • Observer bias: I think dogs are pretty cute, so when I’m out and about, I tend to notice pedestrians with dogs more than I do pedestrians without dogs. So if I see 10 pedestrians and 4 of them have dogs, I’m much more likely to notice and remember the dog people and think that the majority of pedestrians have dogs. Similarly, self described “anti-SSRI advocates” are more likely to notice and prioritize instances where SSRIs occur with violent behavior.
  • Who is observed: I happen to live two blocks from the most popular dog park in town, so people from miles away drive here in order to hike with their dogs. There are a lot of trails that don’t allow dogs and if I lived right next to one of them, I’d likely see a lot more walkers who are dogless. So I’m not looking at the entire population of walkers and dog owners when I’m observing a connection between those two characteristics – I’m looking at a population more likely to suggest to me that the two are connected. Similarly, the SSRI stories are drawn entirely from crime reporting. Stories about people who take SSRIs and do not engage in violent, homicidal, or otherwise criminal behavior are not going to be in a crime story – so the archive is looking at a subset of SSRI-takers that is more likely to confirm their perception that SSRIs cause criminal behavior.
  • Interpreting evidence to fit desired results: when growing up, I tried out the “dogs will make me walk and exercise more” argument on my parents. This is because I wanted to get a dog, and I was trying to put together any argument I could to support that conclusion – I had started with the conclusion instead of with the evidence. Some of the stories mentioned in the article make me wonder if the SSRI stories suffer from the same problem. One of the quoted stories is “Lynyrd Skynyrd harmonicist Mike Caruso’s remark that, ‘the doctor put me on Cymbalta. That turned me manic.'” To me, giving an anti-depressant to someone with undiagnosed bipolar and triggering manic behavior is a very different argument than if taking the SSRI created violent or homicidal behavior that hadn’t previously existed in the person.

In order to convince me that SSRI used caused these behaviors in people who otherwise would not display them, I would want to see a clinical study where people were observed before and after starting SSRI treatment and a control group was also monitored while not having SSRI treatment. Those kinds of scientific studies are the only way to meaningfully determine whether the two variables have any kind of causal relationship.[1] And without that data, this article does a lot more harm than good – by reinforcing existing perceptions that criminals are all mentally ill and by shaming or scaring people who take and benefit from SSRIs.

[1] I should note that requests for data and scientific studies are often used to invalidate or minimize reported personal experiences from marginalized groups, an academic privilege argument of sorts. I do and continue to credit individual experiences where SSRI treatment caused specific behaviors for that individual, but I feel very uncomfortable making blanket decisions about whether or not these drugs should be available at all, for anyone, based on third party descriptions of the experiences of others.


  1. Great post, abby … thanks for writing it.
    .-= Cara´s last blog ..One Million =-.

  2. Bravo! I loved the dog examples.

    Sometimes I wonder who all these awesomely healthy people are, who have all this energy to do rant and rave about the “evils” of “big pharma”. Frankly “big pharma” has kept me a) from suicide from depression and b) helped me stay functional physically for many many more years than I ever thought possible.

    Each person should be able to choose from the choices available, what best fits their own situation.

    Should we ban cars because people drink and drive? Should be ban SSRI’s because some people commit crimes while taking them? No and No.

  3. Thanks here also. As someone who also relies on SSRIs (I’m the happiest I’ve been in years since starting them), this is troubling to me as well. It’s not exactly a secret that finding a good drug regime is often trial-and-error.

    For me, my first thought would be not that the SSRIs caused the behaviours, but that they weren’t getting adequate treatment for one reason or another–the drugs weren’t right for them, or weren’t enough on their own, or they weren’t being diligent about taking their meds, etc. As you said, there’s really not enough to go off of, and even if they have bad effects in some people (which, lets face it, all drugs do), that doesn’t negate the good that they do for others.

  4. This may be one of the best numeracy articles I’ve read in quite some time.

  5. Wait, I thought anti-depressants were just happy pills, so people don’t ever have to deal with negative feelings ever! Happy people aren’t violent.
    Or, no, they take away all feelings, don’t they, and turn people into robots or something? Killer robots, maybe?

    Honestly, I just wish people were more critical of actual problems with patient rights and medication and less critical of Big Pharma as some kind of bogeyman. You can’t prove whether Big Pharma is out to get us, but you can prove whether SSRIs increase violence, or whether people are informed that SSRIs can induce mania and what that would look like.

  6. There’s at least one clear classification error: Cymbalta isn’t an SSRI. It’s a member of a related class of drugs, the serotonin/norepinephrine reuptake inhibitors.

    Not that we know how either class of antidepressant meds work to provide relief from depressive symptoms. In those patients who report such relief — serotonin levels increase within days of initiating treatment while improvement in symptoms takes weeks to manifest if improvement manifests at all. The meds we have available are blunt instruments and most come with unintended and sometimes unpleasant effects.

    I personally find mine useful. (No I’m not going to tell you what meds I’m on. Though I get very ranty indeed about risperidone — I found both the intended and unintended effects of it wildly unpleasant.) I have every sympathy for and will lend my support to people who do not find these meds useful or find them injurious and refuse to be treated with them — including people interacting with criminal justice, corrections, and other detention (such as immigration enforcement which is technically violation of administrative and not criminal law) systems. A person’s right to accept or refuse medical treatment should not be abridged because ou has been arrested, convicted of crimes, or detained by the state.

    I will oppose with what little strength I have those who wish to remove the option for anyone to be able to use these meds at all.

  7. There is also the question of whether those with violent tendencies lacked motivation and ability to carry them out until they began treating with SSRIs. I would believe that as well, given that when I began using my psych meds I saw a notable uptick in my ability to actually act on the motivations I possess. It was amazing when I discovered that I could actually get myself out of bed, and take a shower, and go to the library and then read the books I checked out without being too exhausted. I could see someone who had other sorts of thoughts finding the ability to act on them once they were in treatment.

    Regardless, I support anyone who finds them useful and helpful and healing in getting that healing. Those who don’t, don’t need to take them. I’m worried that pieces like this will end up being scare pieces that remove my access to them.

  8. On top of your point about correlation not indicating causation, the fact that 3500 people committed crimes while on SSRIs doesn’t demonstrate a correlation. To demonstrate a correlation between SSRIs and crime, they would have to show that there’s a (statistically significantly) higher proportion of SSRI users among criminals than among the general population. The fact that 3500 crimes out goodness knows how many crimes committed in the time period since SSRIs were introduced were committed by people on SSRIs shows absolutely nothing.

    Also, how many people have SSRIs saved from suicide?

  9. Outstanding post, and lucky you to live so near the dog park!

  10. Wonderful post!

    I admit I’m basically head over heels in love with my SSRI, since it’s doing what it’s supposed to and I feel like myself again, am able to enjoy things, etc. Even if it didn’t work, though,or it had caused me to have suicidcal thoughts and/or feelings (which it could have, though it didn’t), I still wouldn’t think that means everyone else should have them denied to them should they wish to take them.

  11. Thank you for this — I did the “correlation is not causation” line over on Tumblr and then lost track of whether the discussion ever went anywhere productive. I don’t think it did.

  12. My biggest problem with many conclusions made about SSRIs (increased risk of suicidality or violent tendencies, etc.) is that they do not exclude patients who were incorrectly treated with SSRIs for a depressive disorder when they were actually suffering from another illness for which SSRIs might actually be contraindicated, such as bipolar disorder or postpartum psychosis. In these patients, SSRIs could lead to or exacerbate mania and/or psychosis, and could potentially result in increased violence or suicidality. That said, I know that many people with these diagnoses do take SSRIs and find them beneficial, and that some patients who do not have an SSRI-contraindicated illness might experience these issues too. I realize that more is at play here than simple mistreatment of part of the sample population, but I take issue with the “SSRIs cause all these awful things” conclusions when the sample population for these studies includes people who should not have been treated with SSRIs in the first place.

  13. I want to note that Effexor isn’t an SSRI, it’s an SNRI. I was on it briefly but I couldn’t stand the side effects, so I was switched to a similar SNRI, one that had the same active thingy but worked more directly with less side effects.

    Great article. It should be shown to everyone who rants about “big pharma” brainwashing the public with psych meds or whatever.
    .-= PharaohKatt´s last blog ..20th Down Under Feminist Carnival =-.

  14. Not only is Cymbalta not an SSRI, but neither is Effexor. :-/ I know they mention that they’re “related” in the article, but then to pull the “OMG Andrea Yates was on Effexor!” bugs me. I might as well say, “But, OMG, when I was on Effexor, I never drown my [non-existent] children!”

    To continue with Becky’s thoughts, but on the other side of things….how many people are on anti-depressants in this country? In 2005, the stat was 10%…sounds small, but that’s approximately 27 million people. 27 MILLION. And there were 3,500 “stories” (anecdotal evidence, no control whatsoever, etc) of people being violent while on SSRIs. 3,500 is not a small number either, but if we assume that SSRIs do, in fact, cause violent behavior….out of 27,000,000, that’s 0.000013% of people on SSRIs becoming violent. I haven’t done the stats, but I bet that’s probably not statistically significant.

    Plus the complete lack of controls, not factoring how energy levels usually rise before the depressed feelings lift, not factoring in that some of those people were completely misdiagnosed (there’s talk that one of the Columbine boys had anti-social personality disorder; some of these people may have been bipolar and the SSRI caused some violent mania), and completely disregarding that some of these people were most likely diagnosed and treated by a GP and not a psychiatrist (not to knock GP’s, but people should really see pdocs, even if they think it is just depression).

  15. In the case of Andrea Yates, from what I’ve heard, she killed her children because of severe post-partum depression and psychosis, NOT because of the drugs she was on to treat it.

  16. My teenage son, who has complex PTSD that was misdiagnosed for years, completely loses control on SSRIs. This has been proven over and over, up to and including violence, suicide attempts, and running away from the police. Fortunately this isn’t true of Wellbutrin, which has been helpful.

    This is anecdotal and I don’t allow it to affect my feelings about all of these meds. I wish that other people would understand that psych meds and their effects are extremely different for each person. It’s a personal thing, not a broad brush that can be applied to everything. *sigh*