Home » Blog » Crime, Consequences and Mental Illness

Crime, Consequences and Mental Illness

Sometimes you wake up feeling refreshed from a good night’s rest. Other days you wake up feeling a little groggy and less put together.

I can only hypothesize that the latter occurred when the author wrote this post in response to our post pointing out the flaws of associating violence with mental illness based upon the CATIE data.

One of the biggest problems with the violence study done on the CATIE data, which I didn’t explictly mention in my prior post (but which is fairly obvious) is a problem associated with any study attempting to piggyback on another study’s resources. Contrary to the author’s assertion in his blog post, it is not commonplace in social science research to do this. In fact, because of how good study design takes place (a planning process that can take years), studies that piggyback on other study’s subjects, as the violence researchers did, have to live with the original study’s limitations.

Biased Sample, Biased Results

One of those limitations is serious — it chose its sample population based upon the psychopharmacology and medical needs of the study’s focus, not of the violence researcher’s focus. This resulted in a large swath of representative people not being included in the study. Enough people, in fact, to seriously alter the study’s findings had they been included.

The author glosses over this point saying, in effect, “Well, that’s the norm in research.” It may be the norm in psychiatric and medical research, but it’s definitely not in social science research. Especially when that research is seeking to establish cause and effect relationships in specific populations. It’s not common to setup exclusion criteria that have little or nothing to do with the subject under study. The original CATIE researchers had good reasons for their particular exclusion criteria; the violence researchers (Swanson et al.), however, had little research justification for using the same exclusion criteria except that they had no choice. Anything that excludes a significant proportion of the study group you’re researching is going to impact the robustness and validity of your results, as was the case here.

The second point the author makes is again related to the fact that the researchers were piggybacking onto the CATIE study. Since they didn’t have control over these things, we’re just supposed to accept this glaring issue?

Is “Grabbing” the Same as “Being Stabbed by a Knife”?

As for the semantics issue, words have specific meanings, and when people change around words to fit their own needs or agendas, and change the meaning of specific theoretical constructs to fit such needs, it should cause us to sit up and take notice.

Because the researchers changed the wording of the MacArthur Community Violence Interview from “other aggressive acts” (which, in the MacArthur’s team’s view, was specifically different enough from violence as to not include the word violence in its description) to “minor violence,” they make broad, meaningless generalizations suddenly valid. The CATIE violence researchers’ justification (to match a government survey about violence) isn’t sufficient, in our view, since it clouds and distorts the actual data and findings.

We see this in action in how people talk about Swanson’s CATIE study results. Instead of the actual 1.6% difference in violence found, it turns into a whopping 19% difference. If they had left the category to its original name, people wouldn’t simply lump the two together as was done (and is still being done) to justify arguments and the stance that violence and mental illness share some sort of close link. Remember, “other aggressive acts” could include something like a heated argument, where two people end up yelling at each other and one grabs the other’s arm. This is definitely not in the same arena as someone being threatened by a weapon or having a weapon used on them. Yet, if all you did was read other people’s reviews of this research, you’d believe that the mentally ill were 10 times more likely to commit any type of violence with no disclaimer about this differentiation being made to law makers or policy makers.

The 1998 Landmark Study Showed No Violence Link

Remember, the MacArthur Community Violence Interview didn’t appear out of thin air. It came from an important, ground-breaking study by Steadman et al. (1998) that found no significant difference in violence between people with psychiatric diagnoses and the community. This was a study, designed from the ground up, to measure violence. Not an afterthought study that glommed onto a pharmacological study of psychoactive medications.

And yes, I brought up the reliability of self-report amongst the worst of the worst of people grappling with schizophrenia. Anybody who has spent any significant amount of time with a wide variety of people who have been diagnosed with this condition absolutely know what I’m talking about. Now, if the researchers had a more solid baseline set of data than the 42% they did have, that would’ve compensated for reliance on self-report from a historically unreliable population to gain self-report from. But put these two components together, and you have a real question about how valid the data they did find even are.

Apples to Apples

Interestingly, the author didn’t refute the point about what you compare the CATIE violence data with — apples to oranges, or apples to apples? So, even if we were to accept all of the above issues and serious problems with this data, the data is useless without context. Some people have chosen the context of 30-year-old data that used completely different measures of violence as a good control comparison (that magically low 2% number). However, more recent and accurate data — research that uses the exact same violence measure — is readily available via Steadman et al. (1998).

What does that data show?

Excluding substance and alcohol abuse (problems that are widely accepted as being linked to a higher incidence of violence), Steadman’s study found 3.3% had committed violence and 13.5% committed other aggressive acts in the community sample. There is no statistically significant difference between 3.6% (Steadman’s study) and 3.3% (Swanson’s CATIE study).

So the research shows exactly what we’ve said all along — there is no strong or significant link between mental illness and violence.

You’re More Likley to Be Assaulted by Someone Without Mental Illness

Yes, that’s true, if your assault is by a stranger (which is what most people’s fears are).

Steadman et al’s (1998) research showed a 22% stranger violent act rate in the general community, and only a 13.8% stranger violent act rate amongst patients. If you’re assaulted by a stranger, it’s one-third more likely that person has no psychiatric disorder. This was not a statistically significant difference, however, but the data is clearly the opposite of what others suggest is true.

I’d like to compare this with the CATIE violence researcher’s data, but I cannot. The CATIE researchers never bothered to ask who the violence was being perpetrated upon. If you’re doing a violence study, wouldn’t that be an important question to ask and track?

Shame on the Treatment Advocacy Center

By the way, the Treatment Advocacy Center (TAC) should be ashamed of themselves for their fear-mongering ways and promoting the “10 times more likely” number as fact. It is truly embarrassing that an organization of their nature would be misconstruing the research to further its own political, forced-treatment agenda.


Steadman, H.J.; Mulvey, E.P.; Monahan, J.; Clark Robbins, P; Appelbaum, P.S.; Grisso, T.; Roth, L.H.; Silver, E. (1998). Violence by People Discharged From Acute Psychiatric Inpatient Facilities and by Others in the Same Neighborhoods. Arch Gen Psychiatry, 55:393-401.

Crime, Consequences and Mental Illness

John M. Grohol, Psy.D.

Dr. John Grohol is the founder of Psych Central. He is a psychologist, author, researcher, and expert in mental health online, and has been writing about online behavior, mental health and psychology issues since 1995. Dr. Grohol has a Master's degree and doctorate in clinical psychology from Nova Southeastern University. Dr. Grohol sits on the editorial board of the journal Computers in Human Behavior and is a founding board member of the Society for Participatory Medicine. You can learn more about Dr. John Grohol here.

3 comments: View Comments / Leave a Comment
APA Reference
Grohol, J. (2018). Crime, Consequences and Mental Illness. Psych Central. Retrieved on October 30, 2020, from
Scientifically Reviewed
Last updated: 8 Jul 2018 (Originally: 4 May 2007)
Last reviewed: By a member of our scientific advisory board on 8 Jul 2018
Published on Psych All rights reserved.