Mental health services and research have been dominated for several decades by a rather simplistic, reductionistic focus on biological phenomena, with minimal consideration of the social context within which genes and brains inevitably operate. This ‘medical model’ ideology, enthusiastically supported by the pharmaceutical industry, has been particularly powerful in the field of psychosis, where it has led to unjustified and damaging pessimism about recovery. The failure to find robust evidence of a genetic predisposition for psychosis in general, or ‘schizophrenia’ in particular, can be understood in terms of recently developed knowledge about how epigenetic processes turn gene transcription on and off through mechanisms that are highly influenced by the individual's socio-environmental experiences. To understand the emerging evidence of the relationship between adverse childhood events and subsequent psychosis, it is necessary to integrate these epigenetic processes, especially those involving the stress regulating functions of the HPA axis, with research about the psychological mechanisms by which specific types of childhood trauma can lead to specific types of psychotic experiences. The implications, for research, mental health services and primary prevention, are profound.

Declaration of Interest: None of the authors have any conflicts of interest in relation to this paper.

This editorial reviews the relationship between childhood trauma and the development of psychosis in adulthood. There are numerous studies, including large, prospective studies, which clearly support a link between childhood adversity and experience of psychosis later in life. There is also evidence that there is a dose response relationship, and that childhood trauma is particularly associated with the experience of hallucinations and delusional ideas. It is possible that psychosis is a relatively understandable response to the experience of severe trauma, and recent cognitive models of psychosis can help to explain the underlying mechanisms in such a causal relationship. There are obvious treatment implications, which include the need to assess histories of childhood trauma in people with psychosis, the incorporation of trauma in shared understandings of psychosis with service users, the incorporation of change strategies in cognitive behaviour therapy for psychosis that are derived from evidence-based approaches to the treatment of trauma and PTSD, and the prevention of traumatisation by mental health services.

Declaration of Interest: None.

The aim of this Editorial is to describe the association between child sexual abuse and psychosis, and to consider potential mechanisms for the association. The association is strongly supported by the literature. Evidence from a variety of sources is triangulated in order to create a plausible model of the link, which can then be used to direct future research. The mechanisms are certainly complex, and there is evidence of interacting contributions at genetic, neurophysiological, behavioural, cognitive and emotional levels. Child sexual abuse is an important antecedent in psychosis, both theoretically and clinically. At the theoretical level, it potentially illuminates mechanisms by which psychotic symptoms are generated, at the clinical level it opens possibilities for improving cognitive-behavioural approaches to treatment.

Declaration of Interest: None.