Editorial Trauma and psychosis: theoretical and clinical implications There are clearly complex and multiple relation- ships between trauma and psychosis (1). Psychosis can be a traumatic experience and have conse- quences for the individual that may be very similar to PTSD (2). It appears likely that, at least for some people, psychosis can be a reaction to traumatic experiences, given the prevalence of such experiences in people with psychosis, and the links in relation to form and content of psychotic experiences (3). For example, a consis- tent finding in research studies is that childhood sexual abuse seems to be specifically associated with the development of critical or commanding voices in adulthood (4). It is also important to note that in almost every country where surveys have been conducted, the public understands the causes of psychosis in terms of adverse psycho-social events and circumstances more so than biogenetic factors (5). They have continued to do so for decades, despite numerous campaigns designed to teach them that schizophrenia, for instance, is ��an illness like any other�� (6). Despite a recent increase in research devoted to this topic, there are relatively few studies that examine the mechanisms that may explain how trauma may increase vulnerability to psychosis. Recent psychological models of psychosis may help to explain the relationship between the experience of trauma and the development of psychotic experiences, and becoming a patient with a psy- chotic diagnosis. There may be several ways in which traumatic experiences may confer vulnerab- ility to psychosis via cognitive and behavioural processes (1). It is also possible that the cognitive and behavioural consequences of trauma may make people vulnerable to psychosis. Negative beliefs about self, world and others (such as ��I am vulnerable�� and ��Other people are dangerous��) have been shown to be associated with the development of psychotic experiences (7���9). A recent study published in this issue has also shown that such beliefs specifically formed as a result of trauma are related to psychotic experiences in patients (10). Positive beliefs about psychotic experiences (such as ��paranoia is a helpful survival strategy��) may also be related to traumatic experience, and have shown to be associated with the development of psychosis (11). It is likely that psychotic experiences are essen- tially normal phenomena that occur on a con- tinuum in the general population (12). It would seem that the occurrence of trauma in the life history of a person experiencing such phenomena may represent the difference between patients and non-patients (13). It appears that catastrophic or negative appraisals of psychotic experiences result in the associated distress (14, 15). In this context, the study in this issue of Bak et al. (16) is particularly welcome. Their large, prospective study of the general population found that there is a high prevalence of trauma in people who have psychotic experiences associated with distress whereas those without distress had a low preval- ence of trauma. Therefore, consistent with predic- tions of cognitive models, trauma may predispose people to appraising their unusual experiences in a problematic way. In addition, the study by Roy and Janal (17), also published in the present issue, suggests that childhood trauma also affects likeli- hood of suicide attempts, and increased severity of trauma is associated with younger age of first attempt . This is clearly of relevance to people with psychosis, given the high prevalence of trauma and their increased risk of suicide (18). This research also highlights the need to ask service users about traumatic events in their life history. Currently, most child abuse cases, for example, remain undetected by mental heath ser- vices internationally (3). Furthermore there is some evidence that this is especially the case for people with diagnoses indicative of psychosis, and that mental health staff with strong biogenetic causal beliefs are particularly unlikely to ask about childhood trauma (19). We would, therefore, agree with the conclusion of Bak and colleagues that failing to ask about trauma will ��impede installation of appropriate treatment strategies�� and therefore, prolong distress unnecessarily. Bleuler (20) originally described ��the schizophre- nias�� as a group of distinct psychotic disorders with Acta Psychiatr Scand 2005: 112: 327���329 All rights reserved DOI: 10.1111/j.1600-0447.2005.00644.x Copyright �� 2005 Blackwell Munksgaard ACTA PSYCHIATRICA SCANDINAVICA 327

differing aetiologies and outcomes. More recently, there have been several suggestions that there is a subgroup of schizophrenia that is trauma-induced and characterized by a predominance of positive symptoms (21, 22). For example, traumatic psy- chosis is described as an entity in which trauma has a distinct and specific role in terms of the onset and content of psychotic symptoms (21). Often, the underlying trauma has been a sexual or physical assault in childhood or in adult life but bullying has also emerged as a potent aetiological factor (23). The typical presentation is of command, and critical hallucinations with linked somatic and visual hallucinations. These are often directly trauma congruent or linked to the negative sche- matic representations of childhood sexual or physical abuse. Other typical symptoms are fluc- tuating depression with suicidal ideation, delusions of persecution and substance misuse. These symp- tom profiles are consistent with the findings from the research studies outlined above. Such patients are often treatment resistant to pharmacological interventions and case management but may respond well to CBT (24). Another postulated subgroup is that of drug-induced psychosis, and it is evident that drug use is often comorbid with both psychosis and PTSD (25) and may be a response to trauma. The categorization of the psychoses needs to be reconsidered in the light of such findings, with the incorporation of trauma and its consequences. There are several clinical implications of this approach to understand psychosis. Helping service users to identify any links between their traumatic experiences and current psychotic symptoms may help to normalize their experiences, reduce their distress and increase their perceived control. The use of voice diaries with coping strategies and rational responding to critical hallucinations can lead to an early success experience by reducing symptom burden and lessening depression. From a broader perspective, the emerging literature demonstrating the causal role of adverse life events in psychosis would seem to imply that psychosis may be as preventable as other mental health difficulties, and that the mental health community has a responsibility to join others in lobbying for primary prevention programmes targeted at supporting families to care for and protect children in their early years (26). Similarly, we have a responsibility for reducing the potential for treatment experiences themselves, such as acute psychiatric admissions (27), to be traumatizing for service users. The link between trauma and psychosis has a growing body of empirical support, and the implications for treatment should be fairly uncontroversial, and could benefit service users regardless of the aetiology of their mental health problems. It is clearly important to consider the possible role of trauma in the development and maintenance of distressing psychotic experiences and to ask about it. However, it is also important to remember that there are multiple pathways to psychosis, and while trauma is clearly involved for some people with psychosis, there are many others with no history of trauma. Even in such instances, it is possible that they are prone to exacerbation and maintenance of their psychotic experiences, through being traumatized by the subjective experience of psychosis or through subsequent victimization in the community (28). The first book dedicated to psychosis and trauma, expanding on many of the issues raised in this edition, is about to be published (29). Acta Psychiatrica Scandinavica Anthony Morrison, John Read, Douglas Turkington Invited Guest Editors References 1. Morrison AP, Frame L, Larkin W. Relationships between trauma and psychosis: a review and integration. Br J Clin Psychol 2003 42:331���353. 2. Shaw K, McFarlane A, Bookless C. The phenomenology of traumatic reactions to psychotic illness. J Nerv Ment Dis 1997 185:434���441. 3. Read J, van Os J, Morrison AP, Ross CA. Childhood trauma, psychosis and schizophrenia: a literature review and clinical implications. Acta Psychiatr Scand 2005 112: 330���350. 4. Read J, Goodman LA, Morrison AP, Ross CA, Aderhold V. Childhood trauma, loss and stress. In: Read J, Mosher LR, Bentall RP, eds. Models of madness. Hove, UK: Bruner- Routledge, 2004:223���252. 5. Dietrich S, Beck M, Bujantugs B, Kenzine D, Matschinger H, Angermeyer MC. The relationship between public cau- sal beliefs and social distance toward mentally ill people. Aust N Z J Psychiatry 2004 38:348���354. 6. Read J, Haslam N. Public opinion: bad things happen and can drive you crazy. In: Read J, Mosher LR, Bentall RP, eds. Models of madness: psychological, social and biolo- gical approaches to schizophrenia. Hove, UK: Brunner- Routledge, 2004:133���145. 7. Garety PA, Kuipers E, Fowler D, Freeman D, Bebbington PE. A cognitive model of the positive symptoms of psy- chosis. Psychol Med 2001 31:189���195. 8. Morrison AP. The interpretation of intrusions in psychosis: an integrative cognitive approach to hallucinations and delusions. Behav Cogn Psychother 2001 29:257���276. 9. Bentall RP, Corcoran R, Howard R, Blackwood R, Kin- derman P. Persecutory delusions: a review and theoretical integration. Clin Psychol Rev 2001 22:1���50. 10. Kilcommons A, Morrison AP. Relationships between trau- ma and psychosis: an exploration of cognitive and disso- ciative factors. Acta Psychiatr Scand 2005 112:351���359. Editorial 328