Mental disorder is a cause of crime

The next couple of entries in the Forensic Friday series will continue the series on causation by addressing the notion that “mental disorder is a cause of crime”. This statement is really the foundation of forensic psychiatry. 

If mental disorders do not cause crimes, why should we have forensic psychiatry at all? After all, we don't have forensic internal medicine for diabetics who commit crimes, even if they may have done so during hypoglycaemia and need treatment while serving prison.

In coming posts, we will look at the historical roots of forensic psychiatry and adress each of the definitions “mental”, “disorder”, "cause" and “crime” conceptually, epistemologically, and empirically. The blog posts will be based on the paper "Mental disorder is a cause of crime" I co-authored with Susanna Radovic, Christer Svennerlind, Pontus Höglund and Filip Radovic in 2009. Without the collaborative work behind that paper, I wouldn't have been able to write any of the following texts. Many of them will be expanded and up-dated versions of paragraphs from the paper.  Of course, my version of philosphical analysis is over-simplified and not up to the level of my colleagues from philosophy, but I write this from the perspective of a clinician. On the other hand, I will go deeper into empirical data and try to sum up the considerable developments we have seen since 2009. 

Neither “mental”, “disorder” or “crime”, nor the “causation” implied, are clear-cut concepts. “Mental” denotes heterogeneous aspects of a person, such as inner experiences, cognitive abilities, and behaviour patterns, described in a non-physical vocabulary. In psychology and psychiatry, “mental” describes law-bound, caused aspects of human functioning that in some respect are predictable and generalizable. A corner-stone in these sciences is behaviour, as it is the easiest aspect to observe and quantify, and in itself contains a better-than-chance prediction of future behaviour. Indeed, even interviews and other more clearly “mental” assessments focus on reporting behaviours rather than “inner” mental processes.

Problems defined as “disorders” seem to be end-points of dimensional inter-individual differences rather than natural categories.

Deficits in cognitive faculties, such as attention, verbal understanding, and reality assessment, may be susceptibility factors that relate to behaviours, such as crimes, as risk factors in the sense of increasing the probability for a specific negative behaviour, and/or as causes in the sense of INUS conditions (insufficient but non-redundant parts of unnecessary but sufficient conditions).

Neurobiological measures (e.g. regional brain activity, neurotransmitters, genetics) may be related to crimes in a similar way as assessments of mental health problems or cognitive faculties.

Attributing causation to behaviours is not unbiased, and factors we feel estranged from, such as mental disorders, tend to attract disproportionate attention in explaining abject behaviours, such as crimes. 

When a forensic psychiatrist testifies in court, (s)he may describe mental health assessments, effects on accountability and ability, but the court and laypersons will understand what is said in terms of “causation”. Sometimes we are either lead to or volunteering to proffer an opinion on causation per se. I hope that this blog series will clarify what we can know and what we can’t know about whether mental disorders cause crimes based on psychiatry and psychology. To be continued.