Mental disorder is a cause of crime: the cornerstone of forensic psychiatry.

The assumption that mental disorder is a cause of crime is the foundation of forensic psychiatry, but conceptual, epistemological, and empirical analyses show that neither mental nor crime, or 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 are predictable and generalizable. Problems defined as mental disorders are end-points of dimensional inter-individual differences rather than natural categories. Deficits in cognitive faculties, such as attention, verbal understanding, impulse control, and reality assessment, may be susceptibility factors that relate to behaviours (such as crimes) by increasing the probability (risk) for a negative behaviour or constitute causes in the sense of INUS conditions (Insufficient but Non-redundant parts of Unnecessary but Sufficient conditions). Attributing causes to complex behaviours such as crimes is not an unbiased process, and mental disorders will attract disproportionate attention when it comes to explanations of behaviours that we wish to distance ourselves from. Only by rigorous interpretation of what psychiatry actually can inform us about, using empirical analyses of quantified aggressive antisocial behaviours and their possible explanatory factors, can we gain a clearer notion of the relationship between mental disorder and crime.