Environment and schizophrenia: environmental factors in schizophrenia: childhood trauma--a critical review

There is renewed interest in the relationship between early childhood trauma and risk of psychosis in adulthood. There are a large number of studies of psychiatric inpatients, and of outpatients in which a majority have a psychotic disorder, that suggest the prevalence of childhood trauma in these populations is high. However, these are generally small studies of diagnostically heterogeneous and chronic samples and, as such, can tell us very little about whether childhood trauma is of etiological importance in psychosis. A small number of recent population-based studies provide more robust evidence of an association, and there are now plausible biological mechanisms linking childhood trauma and psychosis. However, there remain a number of conceptual and methodological issues, which mean much more research is needed before firm conclusions can be drawn about whether childhood trauma is a cause of psychosis.     

The relationship between childhood trauma history and the psychotic subtype of major depression

Gaudiano BA, Zimmerman M. The relationship between childhood trauma history and the psychotic subtype of major depression. Objective: Increasing evidence exists linking childhood trauma and primary psychotic disorders, but there is little research on patients with primary affective disorders with psychotic features. Method: The sample consisted of adult out‐patients diagnosed with major depressive disorder (MDD) at clinic intake using a structured clinical interview. Patients with MDD with (n = 32) vs. without psychotic features (n = 591) were compared as to their rates of different types of childhood trauma. Results: Psychotic MDD patients were significantly more likely to report histories of physical (OR = 2.81) or sexual abuse (OR = 2.75) compared with non‐psychotic MDD patients. These relationships remained after controlling for baseline differences. Within the subsample with comorbid post‐traumatic stress disorder, patients with psychotic MDD were significantly more likely to report childhood physical abuse (OR = 3.20). Conclusion: Results support and extend previous research by demonstrating that the relationship between childhood trauma and psychosis is found across diagnostic groups.     

Impact of Different Childhood Adversities on 1-Year Outcomes of Psychotic Disorder in the Genetics and Psychosis Study

While the role of childhood adversity in increasing the risk of psychosis has been extensively investigated, it is not clear what the impact of early adverse experiences is on the outcomes of psychotic disorders. Therefore, we investigated associations between childhood adversity and 1-year outcomes in 285 first-presentation psychosis patients. Exposure to childhood adversity prior to 17 years of age was assessed using the Childhood Experience of Care and Abuse Questionnaire. Data on illness course, symptom remission, length of psychiatric hospitalization, compliance with medication, employment, and relationship status were extracted from clinical records for the year following first contact with mental health services for psychosis. Seventy-one percent of patients reported exposure to at least 1 type of childhood adversity (physical abuse, sexual abuse, parental separation, parental death, disrupted family arrangements, or being taken into care). No robust associations were found between childhood adversity and illness course or remission. However, childhood physical abuse was associated with almost 3-fold increased odds of not being in a relationship at 1-year follow-up compared to patients who did not report such adverse experiences. There was also evidence of a significant association between parental separation in childhood and longer admissions to psychiatric wards during 1-year follow-up and 2-fold increased odds of noncompliance with medication compared to those not separated from their parents. Therefore, our findings suggest that there may be some specificity in the impact of childhood adversity on service use and social functioning among psychosis patients over the first year following presentation to mental health services.Key words: first episode, illness course, psychosis, trauma, psychotic symptoms, service use     

Childhood trauma and psychosis - what is the evidence?

In the last decade, a substantial number of population-based studies have suggested that childhood trauma is a risk factor for psychosis. In several studies, the effects held after adjusting for a wide range of potentially confounding variables, including genetic liability for psychosis. Less is known about the mechanisms underlying the association between childhood trauma and psychosis. Possible pathways include relationships between negative perceptions of the self, negative affect, and psychotic symptoms, as well as biological mechanisms such as dysregulated cortisol and increased sensitivity to stress. Psychotic patients with a history of childhood trauma tend to present with a variety of additional problems, including post-traumatic stress disorder, greater substance abuse, higher levels of depression and anxiety, and more frequent suicide attempts. Initial studies suggest that trauma-specific treatments are as beneficial for these patients as for other diagnostic groups.     

Childhood negative experiences and subclinical psychosis in adolescence: a longitudinal general population study

Background: Accumulating evidence suggests that experiences of trauma and victimization during childhood are associated with an increased risk to develop clinical and subclinical psychosis in adulthood. A recent cross‐sectional study showed a significant association between trauma and psychotic experiences in adolescents. The current study aimed to extend these findings by investigating the longitudinal effects of negative life experiences on the risk for subclinical psychotic symptoms 2 years later in an adolescent general community sample. Methods: Data were derived from the standard health screenings of the Youth Health Care Divisions of the Public Health Services, in the South of the Netherlands. A total of 1129 adolescents filled out a self‐report questionnaire at age 13/14 years and 2 years later (15/16 years), assessing psychotic experiences, as well as experiences of being bullied, sexual trauma, and negative life events. Results: Logistic regression analyses revealed that sexual trauma increased the risk for psychotic symptoms 2 years later. Life events contributed to the risk for psychosis over time and psychosis in turn gave rise to new life events. No significant association with bullying was found after controlling for confounders. Conclusion: The results provide further evidence for an association between childhood environment and psychosis in the crucial developmental period of early adolescence. Early and later psychological stress, if severe, may impact on the risk for psychosis in adolescence through mechanisms of person–environment interaction and correlation.     

Sex differences in the effect of childhood trauma on the clinical expression of early psychosis

Childhood trauma, a risk factor of psychosis, is associated the clinical expression of the illness (greater severity of psychotic symptoms; poorer cognitive performance). We aimed to explore whether there are sex differences in this relationship. We studied 79 individuals with a psychotic disorder (PD) with < 3 years of illness and 59 healthy subjects (HS). All participants were administered the MATRICS Cognitive Consensus Cognitive Battery (MCCB) to assess cognition. Depressive, positive and negative psychotic symptoms, and global functioning were also assessed. History of childhood trauma was assessed using the Childhood Trauma Questionnaire (CTQ). Patients reported a greater history of childhood trauma on all CTQ domains (emotional, physical and sexual abuse, and physical and emotional neglect). A poorer cognitive performance was also observed in PD when compared to HS. No sex differences were found in the CTQ scores. In the relationship between childhood trauma and psychopathological symptoms, significant correlations were found between CTQ scores and positive and negative psychotic symptoms, depressive symptoms and poorer functionality, but only in women. Childhood trauma was associated with poorer social cognition in both men and women. Of all CTQ dimensions, emotional neglect and physical neglect were more clearly associated with a more severe psychopathological and cognitive profile. Our results suggest that childhood trauma, particularly emotional and physical neglect, is associated with the clinical expression of psychosis and that there are sex differences in this relationship.     

Childhood trauma and increased stress sensitivity in psychosis

Lardinois M, Lataster T, Mengelers R, van Os J, Myin‐Germeys I. Childhood trauma and increased stress sensitivity in psychosis. Objective: The notion that traumatic experiences in childhood may predict later psychotic outcomes would be strengthened if a plausible mechanism could be demonstrated. Because increased stress sensitivity is part of the behavioural expression of psychosis liability, the possible mediating role of childhood trauma was investigated. Method: Fifty patients with psychosis were studied with the experience sampling method to assess stress reactivity in daily life, defined as emotional and psychotic reactivity to stress. Traumatic experiences in childhood were assessed with the Childhood Trauma Questionnaire. Results: A significant interaction was found between stress and CT on both negative affect (event stress: β = 0.04, P < 0.04; activity stress: β = 0.12, P < 0.001) and psychotic intensity (event stress: β = 0.06, P < 0.001; activity stress: β = 0.11, P < 0.001), showing that a history of CT is associated with increased sensitivity to stress. Conclusion: A history of childhood trauma in patients with psychosis is associated with increased stress reactivity later in life, suggestive for an underlying process of behavioural sensitization.     

Does dissociation mediate the relationship between childhood trauma and hallucinations,delusions in first episode psychosis?

BackgroundChildhood trauma has been linked to the presence of delusions and hallucinations in psychosis, although the mechanisms underlying this relationship require elucidation. Dissociation, characterized by disruptions to the integrative functioning of several core mental domains, has emerged as a potential mechanism. There is a paucity of research using a clinician-rated measure of dissociation to test the indirect effect of dissociation on the relationship between childhood trauma and psychotic symptoms. This study aimed to investigate whether dissociation mediated both the relationships between childhood trauma and hallucinations, and childhood trauma and delusions utilizing a clinician-administered measure of dissociation, namely the Structured Clinical Interview for DSM-IV Dissociative Disorders - Revised (SCID-D-R).MethodSixty-six first-episode psychosis (FEP) participants completed a research interview and questionnaires. Information about experiences of childhood trauma, psychosis, dissociation, general psychopathology and demographics were collected.ResultsWhen using the SCID-D-R, childhood trauma positively correlated with dissociation. Further, dissociation mediated the relationship between childhood trauma and delusions. Contrary to previous findings, we found no relationship between dissociation and hallucinations and no mediating effect of dissociation on the association between childhood trauma and hallucinations. The results of the SCID-D-R differed significantly from those of the Dissociative Experiences Scale-II (DES-II) which were consistent with previous research.ConclusionsOur findings are the first to use a clinician-rated measure to test the mediating effect of dissociation on the relationship between childhood trauma and positive symptoms (i.e., hallucinations and delusions). Given the discrepancies in results between the SCID-D-R and DES-II, how dissociation is measured in future research is an important consideration. The results add to a body of work that increasingly recognizes the importance of dissociative symptoms on the relationship between childhood trauma and psychosis. The results suggest that dissociative symptoms should be part of routine assessment in those with a history of trauma and present to FEP services.     

Childhood trauma, psychosis and schizophrenia: a literature review with theoretical and clinical implications

OBJECTIVE: To review the research addressing the relationship of childhood trauma to psychosis and schizophrenia, and to discuss the theoretical and clinical implications. METHOD: Relevant studies and previous review papers were identified via computer literature searches. RESULTS: Symptoms considered indicative of psychosis and schizophrenia, particularly hallucinations, are at least as strongly related to childhood abuse and neglect as many other mental health problems. Recent large-scale general population studies indicate the relationship is a causal one, with a dose-effect. CONCLUSION: Several psychological and biological mechanisms by which childhood trauma increases risk for psychosis merit attention. Integration of these different levels of analysis may stimulate a more genuinely integrated bio-psycho-social model of psychosis than currently prevails. Clinical implications include the need for staff training in asking about abuse and the need to offer appropriate psychosocial treatments to patients who have been abused or neglected as children. Prevention issues are also identified.     

Assaultive trauma and illness course in psychotic bipolar disorder: findings from the Suffolk county mental health project

OBJECTIVE: Little is known about the relationship of assaultive trauma to clinical and functional outcome in patients with bipolar disorder. METHOD: We assessed trauma histories in a cohort of 109 first-admission bipolar patients with psychosis using structured interviews and medical records. Assaultive trauma included rape, physical attacks, and physical threats. Outcome was assessed using standardized ratings. RESULTS: Forty percent reported a history of assaultive trauma, mostly in childhood (< or =16 years). Exposed patients were more symptomatic at each follow-up than unexposed. Sixteen percent of exposed patients remitted after one episode compared with 38.5% of the non-exposed. Patients exposed as adults were the most symptomatic at 6 months, while patients exposed in childhood were the most symptomatic at 24 months. CONCLUSION: Our findings supported the salient role of trauma history as a risk factor for poor course in severe bipolar disorder. Given the high prevalence of such exposure, clinical awareness in first-admission psychotic bipolar patients is critical.     

Childhood adversities increase the risk of psychosis: a meta-analysis of patient-control, prospective- and cross-sectional cohort studies

Evidence suggests that adverse experiences in childhood are associated with psychosis. To examine the association between childhood adversity and trauma (sexual abuse, physical abuse, emotional/psychological abuse, neglect, parental death, and bullying) and psychosis outcome, MEDLINE, EMBASE, PsychINFO, and Web of Science were searched from January 1980 through November 2011. We included prospective cohort studies, large-scale cross-sectional studies investigating the association between childhood adversity and psychotic symptoms or illness, case-control studies comparing the prevalence of adverse events between psychotic patients and controls using dichotomous or continuous measures, and case-control studies comparing the prevalence of psychotic symptoms between exposed and nonexposed subjects using dichotomous or continuous measures of adversity and psychosis. The analysis included 18 case-control studies (n = 2048 psychotic patients and 1856 nonpsychiatric controls), 10 prospective and quasi-prospective studies (n = 41,803) and 8 population-based cross-sectional studies (n = 35,546). There were significant associations between adversity and psychosis across all research designs, with an overall effect of OR = 2.78 (95% CI = 2.34-3.31). The integration of the case-control studies indicated that patients with psychosis were 2.72 times more likely to have been exposed to childhood adversity than controls (95% CI = 1.90-3.88). The association between childhood adversity and psychosis was also significant in population-based cross-sectional studies (OR = 2.99 [95% CI = 2.12-4.20]) as well as in prospective and quasi-prospective studies (OR = 2.75 [95% CI = 2.17-3.47]). The estimated population attributable risk was 33% (16%-47%). These findings indicate that childhood adversity is strongly associated with increased risk for psychosis.     

Childhood trauma and dissociation in first-episode psychosis,chronic schizophrenia and community controls

Increasing evidence supports the role of childhood trauma in the etiology of psychosis but underlying mechanisms are poorly understood. Early maltreatment has been linked to dissociative symptoms in psychosis patients. We explored associations between childhood trauma (Childhood Trauma Questionnaire) and dissociation (Dissociative Experiences Scale) in first-episode psychotic patients (n=62), chronic psychotic patients (n=43), and non-psychotic community controls (n=66). Multivariate analyses of covariance were used to test associations between childhood trauma and dissociation by group while controlling for sex. Chronic patients reported the highest level of dissociation. More severe childhood trauma was associated with greater dissociative symptoms in all groups although most strongly in chronic patients. Emotional abuse showed the strongest associations with dissociation, with these being strongest for chronic patients, followed by first-episode patients — and least for controls. Men showed a stronger association between physical neglect and dissociation than women, irrespective of group. There were no significant group by sex interactions. Our findings replicate the strong association between childhood trauma and dissociative symptoms in chronic and first-episode psychotic patients relative to non-psychotic control subjects. We also demonstrate the salience of emotional abuse in explaining variance in dissociation, especially in chronic patients.     

Do cognitive schema mediate the association between childhood trauma and being at ultra-high risk for psychosis?

Exposure to childhood trauma has been associated with psychotic symptoms, being at ultra-high risk for psychosis (UHR), and psychotic disorders such as schizophrenia. Negative self-beliefs have been shown to partially mediate the relationship between childhood trauma and paranoia and have been shown to be characteristic of patients with psychosis. However, whether the association between childhood trauma and being at high risk of developing psychosis (e.g., UHR) and paranoia symptoms is mediated by altered cognitive schema is unknown and warrants investigation to inform preventive interventions. Data was collected on 30 UHR patients from Outreach and Support in South London about exposure to childhood trauma, cognitive schema, paranoia and cannabis use. Relative to healthy controls (n = 38), UHR patients were significantly more likely to report exposure to various types of childhood trauma (emotional and sexual abuse, and emotional and physical neglect), had more negative schema and less positive schema about themselves and others, and were more likely to use cannabis more than once a month. Emotional neglect was found to be significantly associated with UHR status even after controlling for the effects of previous exposure to cannabis use (b = 0.262, 95% CI: 0.115–0.408), and this association was partially mediated by negative self-schema (b = 0.045, 95% CI: 0.004–0.159). Similarly, emotional neglect was significantly associated with paranoia (b = 1.354, 95% CI: 0.246-2.462), and this association was partially mediated by negative self-schema (b = 0.988, 95% CI: 0.323-1.895). These findings provide preliminary evidence about the cognitive mechanisms that may underlie the association between childhood trauma and later risk for psychosis.     

Sexual Trauma Increases the Risk of Developing Psychosis in an Ultra High-Risk “Prodromal” Population

Studies indicate a high prevalence of childhood trauma in patient cohorts with established psychotic disorder and in those at risk of developing psychosis. A causal link between childhood trauma and development of psychosis has been proposed. We aimed to examine the association between experience of childhood trauma and the development of a psychotic disorder in a large “Ultra High Risk” (UHR) for psychosis cohort. The data were collected as part of a longitudinal cohort study of all UHR patients recruited to research studies at the Personal Assessment and Clinical Evaluation clinic between 1993 and 2006. Baseline data were collected at recruitment to these studies. The participants completed a comprehensive follow-up assessment battery (mean time to follow-up 7.5 years, range 2.4–14.9 years), which included the Childhood Trauma Questionnaire (CTQ), a self-report questionnaire that assesses experience of childhood trauma. The outcome of interest was transition to a psychotic disorder during the follow-up period. Data were available on 233 individuals. Total CTQ trauma score was not associated with transition to psychosis. Of the individual trauma types, only sexual abuse was associated with transition to psychosis (P = .02). The association remained when adjusting for potential confounding factors. Those with high sexual abuse scores were estimated to have a transition risk 2–4 times that of those with low scores. The findings suggest that sexual trauma may be an important contributing factor in development of psychosis for some individuals.Key words: trauma, psychosis, ultra high risk     

Linking posttraumatic stress disorder and psychosis: a look at epidemiology, phenomenology, and treatment

Several recent studies have provided direct evidence for the link between posttraumatic stress disorder (PTSD) and psychosis. Patients with psychotic disorders are known to be at a higher risk of traumatization and PTSD. Additionally, preclinical and clinical data suggest that the effects of trauma exposure on neural networks may provide a common diathesis for disorders like PTSD and schizophrenia. This article reviews evidence on a) the magnitude of association between PTSD and psychosis, b) the causal mechanisms implicated, and c) treatment considerations relevant to this association. A comprehensive MEDLINE search was conducted, and articles pertinent to epidemiological, clinical, and treatment aspects of comorbid PTSD and psychosis were identified. High rates of PTSD characterize patients with severe mental illness. Psychotic phenomena may also be a relatively common manifestation in patients with chronic PTSD. However, in clinical settings, the diagnosis is often missed, and few systematic guidelines exist for the identification and treatment of these comorbidities. Future neurobiological and treatment studies may be useful in better informing the clinical management of these subgroups.     

Childhood trauma and psychotic disorders: a systematic, critical review of the evidence

There is controversy over whether childhood trauma (CT) is a causal factor in the development of psychosis. This review aims to identify and critically analyze the association between CT and psychotic disorders. Studies investigating CT and psychotic disorder were identified by searches of electronic databases and manual searches of references lists, and 46 studies were identified. Forty studies had no control group, only psychiatric control groups, or unmatched, nonpopulation control groups and thus had methodologies that were inadequate to determine the relationship between CT and psychosis. Six studies used appropriate control groups. Three studies found an association between CT and psychosis, 2 found potentially real associations that failed to reach statistical significance, and 1 found no association, tentatively suggesting a relationship between CT and psychotic disorders. Several methodological problems were found in the studies in the review, including the highest quality studies, which limit the strength of the conclusions that can be drawn from them. These were lack of statistical power, lack of attention to moderating or mediating variables, the way in which CT was measured, and the use of cross-sectional research designs. These problems, some of which may be unavoidable in CT research, suggest the need for new and innovative methodologies in the investigation of CT and psychosis. Directions for further research are explored.     

Childhood trauma,BDNF Val66Met and subclinical psychotic experiences. Attempt at replication in two independent samples

Childhood trauma exposure is a robust environmental risk factor for psychosis. However, not all exposed individuals develop psychotic symptoms later in life. The Brain-derived neurotrophic factor (BDNF) Val66Met polymorphism (rs6265) has been suggested to moderate the psychosis-inducing effects of childhood trauma in clinical and nonclinical samples. Our study aimed to explore the interaction effect between childhood trauma and the BDNF Val66Met polymorphism on subclinical psychotic experiences (PEs). This was explored in two nonclinical independent samples: an undergraduate and technical-training school student sample (n = 808, sample 1) and a female twin sample (n = 621, sample 2). Results showed that childhood trauma was strongly associated with positive and negative PEs in nonclinical individuals. A BDNF Val66Met x childhood trauma effect on positive PEs was observed in both samples. These results were discordant in terms of risk allele: while in sample 1 Val allele carriers, especially males, were more vulnerable to the effects of childhood trauma regarding PEs, in sample 2 Met carriers presented higher PEs scores when exposed to childhood trauma, compared with Val carriers. Moreover, in sample 2, a significant interaction was also found in relation to negative PEs. Our study partially replicates previous findings and suggests that some individuals are more prone to develop PEs following childhood trauma because of a complex combination of multiple factors. Further studies including genetic, environmental and epigenetic factors may provide insights in this field.     

Do Child Abuse and Maltreatment Increase Risk of Schizophrenia?

Introduction

IntroductionaaAlthough childhood abuse is a recognised risk factor for depression, post-traumatic stress disorder, and substance misuse, its role in the aetiology of psychotic disorder remained controversial. This is in part because the putative effect of childhood trauma on psychosis has been mostly evaluated by small, cross sectional, uncontrolled studies that raised methodological issues.

Methods

Papers concerning the association between childhood trauma and psychotic disorders (to November, 2011) were identified using a comprehensive search of PubMed, Psychinfo, and Scopus and analysing reference list of relevant papers. A narrative synthesis was used to summarise results.

Results

An association between childhood abuse and psychotic symptoms was consistently reported by large cross sectional surveys with an effect ranging from 1.7 to 15. However, we cannot conclude that the relationship is causal as lack of longitudinal studies prevent us from fully excluding alternative explanations such as reverse causality. Gender, cannabis use, and depressive and post-traumatic stress disorder symptoms appear to moderate the effect of childhood trauma on psychotic disorders. However, specificity of childhood abuse in psychotic disorders and, particularly, in schizophrenia has not been demonstrated.

Conclusion

Although the association between childhood abuse and psychosis has been replicated, the etiological role of such early adversity has yet to be fully clarified. So far none of the studies reported support the hypothesis that childhood abuse is either sufficient or necessary to develop a psychotic disorder. It seems likely that any effect of childhood abuse on schizophrenia needs to be understood in terms of genetic susceptibility and interaction with other environmental risk factors.     

Is there a link between childhood trauma, cognition, and amygdala and hippocampus volume in first-episode psychosis?

Patients with psychosis have higher rates of childhood trauma, which is also associated with adverse effects on cognitive functions such as attention, concentration and mental speed, language, and verbal intelligence. Although the pathophysiological substrate for this association remains unclear, these cognitive deficits may represent the functional correlate of changes observed in relation to trauma exposure in structures such as the amygdala and the hippocampus. Interestingly, these structures are often reported as altered in psychosis. This study investigated the association between childhood trauma, cognitive function and amygdala and hippocampus volume, in first-episode psychosis. We investigated 83 patients with first-episode psychosis and 63 healthy controls. All participants underwent an MRI scan acquired with a GE Sigma 1.5-T system, and a standardized neuropsychological assessment of general cognition, memory, processing speed, executive function, visuo-spatial abilities, verbal intelligence, and language. In a subsample of the patients (N=45) information on childhood trauma was collected with the Childhood Experience of Care and Abuse Questionnaire (CECA.Q). We found that amygdala, but not hippocampus, volume was significantly smaller (p=0.001) in patients compared to healthy controls. There was a trend level interaction for hippocampus volume between group and sex (p=0.056). A history of childhood trauma was associated with both worse cognitive performance and smaller amygdala volume. This smaller amygdala appeared to mediate the relationship between childhood trauma and performance on executive function, language and verbal intelligence in patients with psychosis. This points to a complex relationship between childhood trauma exposure, cognitive function and amygdala volume in first-episode psychosis.     

Psychotic experiences in the context of depression: The cumulative role of victimization

Previous studies have reported an association between depression and psychotic experiences, but little is known about what drives this co-occurrence. This study tests the hypothesis that exposure to trauma and bullying may strengthen the relation between depression and psychotic experiences. A total of 799 college students completed self-report questionnaires on psychotic experiences, depression, bullying, and sexual trauma. Hierarchical linear regression analyses were conducted to test the direct relationship between depression and psychotic experiences, as well as interactions. Approximately 20% of respondents reported a history of being bullied, and 7% reported exposure to childhood sexual trauma. There was a significant direct relationship between depression and psychotic experiences. The association between depression and psychotic experiences was significantly stronger among respondents who were victims of both bullying and sexual violence compared to those who experienced either exposure alone, or who were not exposed to either form of victimization. These findings suggest that cumulative exposure to trauma and victimization may contribute to the co-occurrence of depression and psychotic experiences. History of victimization should be assessed among individuals with depressive symptoms to improve treatment plans and outcomes.