Thought of as two distinct phenomena, the connection has been postulated as leading from mental disorder to crime and to be, at least in some respect, causal. At the same time, it is evident that causation in this context cannot mean that mental disorder is a necessary or sufficient cause of crimes.
In other cases, risk factors can be judged to be coincidental to or reflections of common causes. By using probabilism in this way, scientific exploration has been made possible beyond experimental models testing causation. The terms “risk” and “risk factors” are assigned to the cardiologist Dawber (Kannel, Dawber, Kagan, Revotskie & Stokes, 1961) as a model to identify background factors, such as elevated blood pressure, cholesterol, and smoking, behind coronary heart disease. They have become central to medical research and have even come to represent a paradigmatic feature of today's society (Beck, 1992). The concept of risk is therefore a means of avoiding statements of causation, and “explanatory value” in this context will mean “proportion of the variation statistically related to the variation in the risk factor”, which does not necessarily “explain” it in the common, causal meaning of the word.
Human minds, however, strive to attribute causes in order to be able to predict what will happen in the future. Only in very rare instances are such attributions of causation based on experiments or strict, logical deductions. As the factors that may be shown to cause human actions in the INUS sense are invariably numerous and interact in complex constellations, the way we identify causes and assign importance to them is in itself the object of psychological research (Cheng, 1997).
In forensic psychiatric research and expert opinion, the attribution of causation has no doubt been influenced by ideas developed within the professional psychiatric paradigm. And for the causation that is to be judged by the lawyer, counter-faction will be non-informative. How could any mental condition (i.e. inner experiences, cognitions, and/or behaviour patterns) be ruled out as a contributing factor in the very complex sets of factors influencing human action?
This blog post is to a large extent excerpted from the paper "Mental disorder is a cause of crime" I co-authored with Susanna Radovic, Christer Svennerlind, Pontus Höglund and Filip Radovic in 2009.