Map of life expectancy at birth from Global Education Project.

Monday, January 10, 2011

"A deranged killer"

For reasons which should be obvious, I did a little research into the association of schizophrenia with violence. This review article offers a good, clear discussion of the issues.

Although various numbers are bandied about for the degree of risk of violent behavior associated with schizophrenia, they should all be viewed with a degree of skepticism. There are several reasons why it is difficult to put a firm number on this association:

  1. Schizophrenia is not a definite entity. There is no "gold standard" diagnostic test, it's based on clinical judgment. In research settings, it's often based on something short of adequate clinical judgment, such as a single encounter with a clinician. And the term undoubtedly encompasses more than one disease. The etiology of schizophrenia is unknown, and its associated biology very poorly understood.
  2. All this means there are big problems with ascertainment bias. Maybe people who commit violent acts are more likely to be diagnosed with schizophrenia, because they come to the attention of potential diagnosticians; or because their behavior itself predisposes to a diagnosis.
  3. On the other hand, selection bias probably works in the opposite direction. People with major mental disorders who are violent are less likely to agree to participate in studies, more likely to drop out, and harder to follow and recruit.
  4. Studies based on people who have been convicted of violent crimes may understate the prevalence of schizophrenia because people with mental illnesses are often diverted from the criminal justice system. Also, schizophrenia could affect one's likelihood of being caught and convicted. One would think it would make it higher since the ability to plan and act rationally is impaired.
  5. Ascertaining violent behavior is just difficult. Reliance on self-reports could obviously bias conclusions either way.
Still, triangulating on this question from many directions -- trying to ascertain the likelihood of violent behavior in people diagnosed with schizophrenia; trying to ascertain the prevalence of schizophrenia in people who have committed violence; and cross-sectional or even better, prospective cohort studies of community populations -- it appears that the risk of committing violence is higher among people with schizophrenia. It's still a a minority of all people with the diagnosis, but it appears that the risk of committing homicide is somewhere around 8 to 10 times that of people without diagnosed mental illness. Substance abuse disorders also predispose to violence, and definitely create a strong additive risk in people with schizophrenia. It has been said that conduct disorders are also strongly associated with risk but that's obviously circular since violent behavior is a diagnostic criterion for conduct disorder. Keep in mind, however, that people who are diagnosable with schizophrenia commit a small percentage of all violent acts, and that the vast majority of people with schizophrenia are not violent. We need to be honest about this problem without promoting stigma or discrimination.

As far as politically motivated, or apparently politically motivated violence is concerned, there are a couple of famous cases that are relevant. John Salvi, who went on a murderous rampage at two abortion clinics near my home, was indeed a devout Catholic who attended anti-abortion protests and associated with anti-abortion activists. He was also without a doubt psychotic. He ultimately took his own life in prison after receiving a life sentence. Ted Kaczynski was diagnosed with schizophrenia by a court appointed psychiatrist, but I find this highly questionable. He clearly has impairments in social skills and empathy, and he's a weird guy, but his thinking is neither delusional nor disordered as far as I can tell. (I don't condone long distance diagnosis and I'm not a psychiatrist, but I just don't think he meets the criteria for schizophrenia so there.) Both of these individuals did indeed subscribe to coherent political ideologies, which were broadly similar to ideas promoted by movements and organizations, although Kaczynski appeared to believe that his thinking was highly original.

But it's a pretty big stretch to say that those ideologies and their champions are to blame for these people's actions. Other anti-abortion terrorists clearly were acting with intent based on the logic of their ideology, but Salvi actually believed that he would be ordained as a priest after committing his crime. And I know of no other deep ecology proponents who mail bombs. Earth First! and similar organizations attack property, but not people. We've heard a lot of nonsense of all descriptions about the tragic events in Tucson, but here's what I think. The guy is completely nuts. Yes, the violent and eliminationist rhetoric coming from the extreme right -- which is the center of the Republican Party -- is atrocious and must stop. But it's a real leap to say it had something to do with this incident.

Update: To clarify, I'm not saying it didn't. I'm just saying we don't know yet. And it is certainly true that all the violent rhetoric that's out there is dangerous in part because it can influence delusional systems such as John Salvi's. I'm just trying to carefully sort these matters out, that's all.


kathy a. said...

violent political rhetoric -- which is pretty common these days -- is terrible because it poisons the atmosphere, incites hateful thinking, makes real discourse impossible. and also, sometimes crazy people take them seriously.

kazcinsky's diagnosis was not just a single drive-by, but was rendered by multiple mental health experts -- including, if i recall, at least one prison psychiatrist -- and based on lots and lots of underlying information.

all that info was once available on the web, and maybe still is somewhere. but it was a VERY strong showing. it's very easy to armchair diagnose from a distance, but that's not what happened with ted k.'s mental health diagnoses.

Cervantes said...

I definitely agree that Ted is crazy, nuts, fucked up, and weird. But I also think that the Schizophrenia label is basically because they didn't know what else to call him. He very clearly does not display some of the distinguishing characteristics of schizophrenia. His thinking, speech and writing are entirely coherent. Loughner's "word salad" writings outbursts are obviously completely different, and are indeed characteristic of schizophrenia.

I also would not call Ted delusional. His ideas are uncommon, but broadly shared by lots of people who are manifestly not mentally ill. Indeed, I'm rather sympathetic, although I see him as quite unrealistic (which is not the same thing as delusional). It's the longing for the Garden of Eden sentiment, basically.

Ted is not paranoid, per se. He is grandiose, but I would put that in the category of personality, not psychosis. Basically, as I said, schizophrenia is not really a single entity. Whatever is going on with Loughner seems similar to Jonathan Salvi, but not like Ted K. Yes, lots of shrinks examined him, but that makes the point, it doesn't contradict it.

kathy a. said...

i disagree. you are normalizing ted, and despite having some high-functioning aspects, ted was not normal at all. i wish i still had access to the materials given to the court at that time. you're committing armchair diagnosis, which is fun and easy ["who wants to play DSM?"], but not very illuminating or accurate. word salad is a nice bright indicator, but it isn't a necesary diagnostic criterion. and also, you're not qualified. so there.

Cervantes said...

Excuse me, I did not say he is normal. I said he is crazy, nuts, weird and fucked up. I don't think that qualifies as "normalizing" him. What I said is that I do not believe schizophrenia is in reality a single entity, and that Ted lacks many of the symptoms normally associated with it. Just saying, "Well you don't have to have those symptoms to be called schizophrenic" essentially proves my point, it doesn't contradict it.