OBJECTIVES: We briefly analyze the concept of causality as applied to psychiatry and put forward an approach based on the notions of weak causal influences and complex causal networks. METHOD: a conceptual analysis of selected articles and books. RESULTS: We present the INUS causation model proposed by the philosopher J.L.Mackie that gets around some of the difficulties related to the presence of multiple interdependent causes, as appears to be the case in mental disorders. This model seemingly works well in PTSD, as shown. CONCLUSION: We suggest that the failure to find "strong" causes for mental disorders may indicate the need to revise our expectations by adopting alternative models of causality.
Causality; mental disorders; INUS; Mackie