Childhood adversity in schizophrenia: a systematic meta-analysis

The Genetics of Stress-Related Disorders: PTSD, Depression, and Anxiety Disorders

Research into the causes of psychopathology has largely focused on two broad etiologic factors: genetic vulnerability and environmental stressors. An important role for familial/heritable factors in the etiology of a broad range of psychiatric disorders was established well before the modern era of genomic research. This review focuses on the genetic basis of three disorder categories-posttraumatic stress disorder (PTSD), major depressive disorder (MDD), and the anxiety disorders-for which environmental stressors and stress responses are understood to be central to pathogenesis. Each of these disorders aggregates in families and is moderately heritable. More recently, molecular genetic approaches, including genome-wide studies of genetic variation, have been applied to identify specific risk variants. In this review, I summarize evidence for genetic contributions to PTSD, MDD, and the anxiety disorders including genetic epidemiology, the role of common genetic variation, the role of rare and structural variation, and the role of gene-environment interaction. Available data suggest that stress-related disorders are highly complex and polygenic and, despite substantial progress in other areas of psychiatric genetics, few risk loci have been identified for these disorders. Progress in this area will likely require analysis of much larger sample sizes than have been reported to date. The phenotypic complexity and genetic overlap among these disorders present further challenges. The review concludes with a discussion of prospects for clinical translation of genetic findings and future directions for research.

Attachment as a partial mediator of the relationship between emotional abuse and schizotypy

Developmental theories highlight the salience of attachment theory in explaining vulnerability towards psychosis. At the same time there is increasing recognition that psychosis is associated with childhood trauma variables. This study explored the interaction between attachment and several trauma variables in relation to schizotypy levels in a non-clinical sample. 283 non-clinical participants completed online measures of schizotypy, attachment, childhood abuse and neglect. When five types of abuse/neglect were entered into a linear regression analysis emotional abuse was the sole independent predictor of schizotypy. Age, attachment anxiety and avoidance were independent predictors after the effects of emotional abuse were controlled for. The overall model was significant, explaining 34% of the variation in schizotypy. Moderation analysis indicated that the effect of emotional abuse was not conditional upon attachment. Parallel mediation analysis indicated small but significant indirect effects of emotional abuse on schizotypy through attachment avoidance (13%) and attachment anxiety (8%). We conclude that emotional abuse contributes to vulnerability towards psychosis both directly and indirectly through attachment insecurity.

Gender Differences in the Physical and Psychological Manifestation of Childhood Trauma and/or Adversity in People with Psychosis

The link between childhood trauma and/or adversity and risk of psychosis is well known. Our aim was to determine the prevalence of childhood trauma and/or adversity in people who have psychotic disorders and to investigate the association between childhood trauma and/or adversity and a range of social and health measures. Participants (n = 391, 42% male) were specifically asked about any experience of childhood trauma and/or adversity. Respondents provided information about education, employment, physical health, and health service utilization. Univariate analyses revealed that childhood trauma and/or adversity was associated with poorer levels of self-reported physical health and social problems. This includes the experience of chronic pain, headaches, arthritis, asthma, and victimization/stigma in men. Participants with a childhood trauma and/or adversity history indicated higher rates of lifetime suicide attempts with women reporting more lifetime depressive symptoms. Multivariate analyses revealed differing profiles in relation to physical and psychological health variable between males and females. Males with the experience of childhood trauma and/or adversity were significantly more likely to report cardiovascular/stroke issues, migraines and anhedonia. Females with the experience of childhood trauma and/or adversity were more likely to report a lifetime history of elevated mood and to be married or in a de facto relationship. There has been very little research into the assessment and treatment of the effects of childhood trauma and/or adversity in adults with psychosis. Childhood trauma and/or adversity may contribute to higher rates of self-reported poor health in men and is associated with increased depression in women. Our findings suggest that interventions to address the effects of past trauma are urgently needed.

Childhood trauma as a risk factor for psychosis: A sib-pair study

BACKGROUND

Childhood trauma, cannabis use and certain personality traits have been related to the development of psychosis. This study uses a sib-pair design to examine the association between childhood trauma and psychosis controlling for cannabis use and neuroticism.

METHODS

We evaluated 60 patient-sibling pairs, conformed by patients with functional psychosis in the first five years of their illness matched with a non-psychotic sibling. In univariate analyses, patients and siblings were compared with McNemar tests and paired-sample t tests. A conditional logistic regression model of the risk of developing psychosis was built. The dependent variable of this model was the patient-sibling status (patient = 1, sibling = 0).

RESULTS

After controlling for cannabis use and neuroticism, the odds of suffering psychosis for subjects who experienced a childhood trauma were 7.3 times higher than the odds for subjects who did not experience a childhood trauma [95% CI, (1.06-50.01); P = 0.04]. Also, after controlling for experiencing childhood trauma and neuroticism, subjects who were heavy cannabis users had odds of suffering psychosis that were 6.4 times higher than the odds of the remaining subjects [95% CI, (1.2-35.2); P = 0.03].

CONCLUSION

Both childhood trauma and cannabis use were significantly associated with an increased risk of suffering functional psychosis. A neurotic personality also contributed independently to this risk. These findings might help improve the prevention of psychosis and the development of specific treatment strategies on this specific population.

The association between psychosis and severe pain in community-dwelling adults: Findings from 44 low- and middle-income countries

Previous studies examining the association between schizophrenia and pain have produced mixed results and data on sub-threshold psychosis or psychotic symptoms and pain are scarce. This study assessed the association between psychosis and severe pain among community-dwelling adults in 44 low- and middle-income countries (LMICs) where no data exists. Data on 235,370 adults aged ≥18 years from the World Health Survey (WHS) 2002-2004 were analyzed. The presence of past 12-month psychotic symptoms was established using four questions from the Composite International Diagnostic Interview. Participants were categorized into four mutually exclusive groups based on whether they had at least one psychotic symptom and/or a lifetime psychosis or schizophrenia diagnosis. Multivariable logistic regression was used to estimate the association between psychosis and past 30-day severe pain. The prevalence of severe pain among those with 0, 1, 2, ≥3 psychotic symptoms was 8.7%, 16.7%, 21.8%, 30.5% respectively. Compared to those with no psychotic symptoms or diagnosis, the ORs (95% CIs) were: at least one symptom without diagnosis [2.17 (1.99-2.38)]; no symptom with diagnosis [2.33 (1.71-3.17)]; at least one symptom and diagnosis [4.27 (3.20-5.71)]. Associations were partly mediated by chronic physical conditions, anxiety, and depression. Despite some limitations such as the use of a single-item question to assess pain, the results of this study suggest that individuals with psychotic symptoms or a psychosis diagnosis should be systematically assessed for pain, and if necessary, receive treatment for pain and its underlying conditions. Future research on the effect of pain management on psychosis outcome is warranted.

Daily stressors and negative life events in children at elevated risk of developing schizophrenia

BACKGROUND

Psychological stress is implicated in the development of schizophrenia, but little is known about experiences of stress among children at elevated risk for the disorder.

AIMS

To examine stressor exposure and reactivity in children with different vulnerability profiles for schizophrenia: (a) children presenting multiple antecedents of schizophrenia (ASz group), (b) children with a family history of schizophrenia (FHx group) and (c) typically developing low-risk (TD) children.

METHOD

Ninety-five children (ASz = 29; FHx = 19; ASz+FHx = 5; TD = 42), identified aged 9-12 years using a community-based screening procedure or as relatives of individuals with schizophrenia, completed questionnaires assessing environmental stressors and psychopathology at age 11-14 years.

RESULTS

Relative to their typically developing peers, children in the FHx and ASz groups were exposed to a greater number of negative life events and a higher frequency of daily stressors, respectively; and were more distressed by these experiences.

CONCLUSIONS

Stress exposure and reactivity may constitute useful targets of early intervention for psychosis.

Interview Investigation of Insecure Attachment Styles as Mediators between Poor Childhood Care and Schizophrenia-Spectrum Phenomenology

Background

Insecure attachment styles have received theoretical attention and some initial empirical support as mediators between childhood adverse experiences and psychotic phenomena; however, further specificity needs investigating. The present interview study aimed to examine (i) whether two forms of poor childhood care, namely parental antipathy and role reversal, were associated with subclinical positive and negative symptoms and schizophrenia-spectrum personality disorder (PD) traits, and (ii) whether such associations were mediated by specific insecure attachment styles.

Method

A total of 214 nonclinical young adults were interviewed for subclinical symptoms (Comprehensive Assessment of At-Risk Mental States), schizophrenia-spectrum PDs (Structured Clinical Interview for DSM-IV Axis II Disorders), poor childhood care (Childhood Experience of Care and Abuse Interview), and attachment style (Attachment Style Interview). Participants also completed the Beck Depression Inventory-II and all the analyses were conducted partialling out the effects of depressive symptoms.

Results

Both parental antipathy and role reversal were associated with subclinical positive symptoms and with paranoid and schizotypal PD traits. Role reversal was also associated with subclinical negative symptoms. Angry-dismissive attachment mediated associations between antipathy and subclinical positive symptoms and both angry-dismissive and enmeshed attachment mediated associations of antipathy with paranoid and schizotypal PD traits. Enmeshed attachment mediated associations of role reversal with paranoid and schizotypal PD traits.

Conclusions

Attachment theory can inform lifespan models of how adverse developmental environments may increase the risk for psychosis. Insecure attachment provides a promising mechanism for understanding the development of schizophrenia-spectrum phenomenology and may offer a useful target for prophylactic intervention.

Psychotic-like experiences and associated socio-demographic factors among adolescents in China

OBJECTIVE

Adolescents with persistent psychotic-like experiences (PLEs) may be at high risk for later development of psychoses. Exploring early age risk factors for PLEs may provide useful information for prevention of mental disorders and improvement of mental health.

METHOD

A total of 5427 adolescents (aged between 10 and 16) participated in a cross-sectional survey, with social and demographic information collected. The Positive Subscale of Community Assessment of Psychic Experiences (CAPE) was used to measure PLEs, and the CAPE Depressive and Negative Subscales were used to examine depressive and negative experiences. The Trauma History Questionnaire (child version) was used to assess experiences of previous traumatic events.

RESULTS

In our study, 95.7% of the adolescents reported more than one episode of PLEs, while 17.2% reported "nearly always" having PLEs. High positive correlations were shown both between frequency scores among experiences of three dimensions (PLEs, depressive and negative experiences), and between frequency and distress scores. Factors associated with a higher risk for more frequent and distressing PLEs include: urban setting, family history of psychiatric illnesses, and higher impact from previous traumatic events at present.

CONCLUSIONS

Episodes of PLEs are common in Chinese adolescents, however only a small proportion have persistent PLEs, with worsening distress as the frequency increased. PLEs shared similar environmental and genetic risk factors not only with the clinical phenotypes, which is consistent with the continuity model of PLEs, but also with depressive and negative experiences, which may imply etiologic relation between different dimensions of psychosis at the subclinical level.

The prevalence and correlates of childhood trauma in patients with early psychosis

OBJECTIVE

To describe the prevalence and demographic, clinical and functional correlates of childhood trauma in patients attending early psychosis clinics.

METHOD

Participants were recruited from outpatients attending four early psychosis services. Exposure to childhood trauma was assessed using the Childhood Trauma Questionnaire (CTQ). Psychopathology was measured using the Positive and Negative Syndrome Scale and the Depression, Anxiety and Stress Scale. Social and vocational functioning and substance use were also assessed.

RESULTS

Over three-quarters of the 100 patients reported exposure to any childhood trauma. Emotional, physical and sexual abuse were reported by 54%, 23% and 28% of patients, respectively, while 49% and 42% of patients reported emotional and physical neglect, respectively. Female participants were significantly more likely to be exposed to emotional and sexual abuse. Exposure to childhood trauma was correlated with positive psychotic symptoms and higher levels of depressive, anxiety and stress symptoms; however, it had no impact on social or vocational functioning or recent substance use.

CONCLUSION

Exposure to childhood trauma was common in patients with early psychosis, and associated with increased symptomatology. Existing recommendations that standard clinical assessment of patients with early psychosis should include inquiry into exposure to childhood trauma are supported.

Child maltreatment and adult psychopathology in an Irish context

One-hundred-ninety-nine adult mental health service users were interviewed with a protocol that included the Childhood Trauma Questionnaire, the Structured Clinical Interviews for Axis I and II DSM-IV disorders, the Global Assessment of Functioning scale, the SCORE family assessment measure, the Camberwell Assessment of Need Short Appraisal Schedule, and the Readiness for Psychotherapy Index. Compared to a U.S. normative sample, Irish clinical cases had higher levels of maltreatment. Cases with comorbid axis I and II disorders reported more child maltreatment than those with axis I disorders only. There was no association between types of CM and types of psychopathology. Current family adjustment and service needs (but not global functioning and motivation for psychotherapy) were correlated with a CM history. It was concluded that child maltreatment may contribute to the development of adult psychopathology, and higher levels of trauma are associated with co-morbid personality disorder, greater service needs and poorer family adjustment. A history of child maltreatment should routinely be determined when assessing adult mental health service users, especially those with personality disorders and where appropriate evidence-based psychotherapy which addresses childhood trauma should be offered.

Incidence of psychotic disorders among first-generation immigrants and refugees in Ontario

BACKGROUND

Evidence suggests that migrant groups have an increased risk of psychotic disorders and that the level of risk varies by country of origin and host country. Canadian evidence is lacking on the incidence of psychotic disorders among migrants. We sought to examine the incidence of schizophrenia and schizoaffective disorders in first-generation immigrants and refugees in the province of Ontario, relative to the general population.

METHODS

We constructed a retrospective cohort that included people aged 14-40 years residing in Ontario as of Apr. 1, 1999. Population-based administrative data from physician billings and hospital admissions were linked to data from Citizenship and Immigration Canada. We used Poisson regression models to calculate age- and sex-adjusted incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for immigrant and refugee groups over a 10-year period.

RESULTS

In our cohort (n = 4,284,694), we found higher rates of psychotic disorders among immigrants from the Caribbean and Bermuda (IRR 1.60, 95% CI 1.29-1.98). Lower rates were found among immigrants from northern Europe (IRR 0.50, 95% CI 0.28-0.91), southern Europe (IRR 0.60, 95% CI 0.41-0.90) and East Asia (IRR 0.56, 95% CI 0.41-0.78). Refugee status was an independent predictor of risk among all migrants (IRR 1.27, 95% CI 1.04-1.56), and higher rates were found specifically for refugees from East Africa (IRR 1.95, 95% CI 1.44-2.65) and South Asia (IRR 1.51, 95% CI 1.08-2.12).

INTERPRETATION

The differential pattern of risk across ethnic subgroups in Ontario suggests that psychosocial and cultural factors associated with migration may contribute to the risk of psychotic disorders. Some groups may be more at risk, whereas others are protected.

Childhood abuse and neglect in relation to the presence and persistence of psychotic and depressive symptomatology

BACKGROUND

The association between childhood trauma and psychotic and depressive symptomatology is well established. However, less is known about the specificity and course of these symptoms in relation to childhood trauma.

METHOD

In a large sample (n = 2765) of patients with psychosis (n = 1119), their siblings (n = 1057) and controls (n = 589), multivariate (mixed-effects) regression analyses with multiple outcomes were performed to examine the association between childhood trauma and psychotic and depressive symptomatology over a 3-year period.

RESULTS

A dose-response relationship was found between childhood trauma and psychosis. Abuse was more strongly associated with positive symptoms than with negative symptoms whereas the strength of the associations between neglect and positive and negative symptoms was comparable. In patients, similar associations between childhood trauma and psychotic or depressive symptoms were found, and in siblings and controls, stronger associations were found between trauma and depressive symptomatology. Childhood trauma was not related to a differential course of symptoms over a 3-year time period.

CONCLUSIONS

In congruence with earlier work, our findings suggest that childhood trauma, and abuse in particular, is associated with (subthreshold) psychosis. However, childhood trauma does not seem to be associated with a differential course of symptoms, nor does it uniquely heighten the chance of developing (subthreshold) psychotic symptomatology. Our results indicate that trauma may instead contribute to a shared vulnerability for psychotic and depressive symptoms.

A critical assessment of the equal-environment assumption of the twin method for schizophrenia

The classical twin method (CTM) is central to the view that schizophrenia is ~80% heritable. The CTM rests on the equal-environment assumption (EEA) that identical and fraternal twin pairs experience equivalent trait-relevant environmental exposures. The EEA has not been directly tested for schizophrenia with measures of child social adversity, which is particularly etiologically relevant to the disorder. However, if child social adversity is more similar in identical than fraternal pairs in the general twin population, the EEA is unlikely to be valid for schizophrenia, a question which we tested in this study. Using results from prior twin studies, we tested if intraclass correlations for the following five categories of child social adversity are larger in identical than fraternal twins: bullying, sexual abuse, physical maltreatment, emotional neglect and abuse, and general trauma. Eleven relevant studies that encompassed 9119 twin pairs provided 24 comparisons of intraclass correlations, which we grouped into the five social exposure categories. Fisher's z-test revealed significantly higher correlations in identical than fraternal pairs for each exposure category (z ≥ 3.53, p < 0.001). The difference remained consistent across gender, study site (country), sample size, whether psychometric instruments were used, whether interviewing was proximate or distant to the exposures, and whether informants were twins or third persons. Combined with other evidence that the differential intraclass correlation for child social adversity cannot be explained by evocative gene-environment covariation, our results indicate that the CTM does not provide any valid indication of genomic effects in schizophrenia.

Childhood trauma is associated with a specific admixture of affective, anxiety, and psychosis symptoms cutting across traditional diagnostic boundaries

BACKGROUND

Meta-analyses link childhood trauma to depression, mania, anxiety disorders, and psychosis. It is unclear, however, whether these outcomes truly represent distinct disorders following childhood trauma, or that childhood trauma is associated with admixtures of affective, psychotic, anxiety and manic psychopathology throughout life.

METHOD

We used data from a representative general population sample (NEMESIS-2, n = 6646), of whom respectively 1577 and 1120 had a lifetime diagnosis of mood or anxiety disorder, as well as from a sample of patients with a diagnosis of schizophrenia (GROUP, n = 825). Multinomial logistic regression was used to assess whether childhood trauma was more strongly associated with isolated affective/psychotic/anxiety/manic symptoms than with their admixture.

RESULTS

In NEMESIS-2, largely comparable associations were found between childhood trauma and depression, mania, anxiety and psychosis. However, childhood trauma was considerably more strongly associated with their lifetime admixture. These results were confirmed in the patient samples, in which it was consistently found that patients with a history of childhood trauma were more likely to have a combination of multiple symptom domains compared to their non-traumatized counterparts. This pattern was also found in exposed individuals who did not meet criteria for a psychotic, affective or anxiety disorder and who did not seek help for subclinical psychopathology.

CONCLUSIONS

Childhood trauma increases the likelihood of a specific admixture of affective, anxiety and psychotic symptoms cutting across traditional diagnostic boundaries, and this admixture may already be present in the earliest stages of psychopathology. These findings may have significant aetiological, pathophysiological, diagnostic and clinical repercussions.

Childhood residential mobility, schizophrenia, and bipolar disorder: a population-based study in Denmark

INTRODUCTION

Childhood adversity is gaining increasing attention as a plausible etiological factor in the development of psychotic disorders. Childhood residential mobility is a potential risk factor that has received little attention in this context.

METHODS

We used registry data to estimate associations of residential mobility with narrow and broad schizophrenia and bipolar disorder across the course of childhood among 1.1 million individuals born in Denmark 1971-1991 and followed from age 15 through 2010. We assessed effect modification by sex, family history of mental disorder, the presence of siblings close in age, and distance moved.

RESULTS

In individual-year models adjusted for family history, urbanicity at birth, and parental age, mobility at all ages except the year of birth was associated with heightened risk of narrow and broad schizophrenia, and risk increased with age at moving and with the number of moves. Further adjustment for mobility at all ages 0-15 revealed associations mainly during the latter half of childhood, which were strongest during adolescence. Associations between mobility and bipolar disorder were fewer and weaker compared to schizophrenia. There was modest evidence of interaction with family history of psychiatric diagnosis, but little evidence for interaction by sex, the presence of closely-aged siblings, or distance moved. Schizophrenia associations did not appear attributable to increased mobility among adolescents with earlier onset.

CONCLUSIONS

Mobility may increase risk for psychotic disorders, particularly schizophrenia. Children may be especially vulnerable during adolescence. Future research should investigate the importance of school changes and the potential for interaction with genetic risk.

Much ado about much: stress, dynamic biomarkers and HPA axis dysregulation along the trajectory to psychosis

OBJECTIVES

In the context of a stress-vulnerability framework, hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis is thought contribute to the risk, onset and course of psychotic illness. However, recent reports regarding static and dynamic features of the HPA axis suggest a more complex set of phenomena at play in the early phases of psychosis.

METHODS

We review literature regarding structural and functional aspects of the HPA axis in subjects at risk for or experiencing the first episode of psychosis, including evidence favoring as well as that which contradicts a model of HPA axis hyperactivation.

RESULTS

Static measures of diurnal cortisol and hippocampal/pituitary volumes suggest that the HPA axis is in a hyperactivated state in early phases of psychosis. In contrast, the dynamic cortisol response to encountered or anticipated stress is blunted in the same populations. These incongruent findings need to be better understood.

CONCLUSIONS

We consider potential explanations for the seemingly contradictory elevation and blunting of HPA biomarkers in the early course of psychosis. Finally, we propose and explore implications of a conceptual model of tonic HPA hyperactivation and phasic HPA blunting that integrates and reconciles these data.

Reduced hippocampal volume and hypothalamus-pituitary-adrenal axis function in first episode psychosis: evidence for sex differences

Background

Hippocampal volume (HV) decline is an important marker of psychosis and has been associated with hypothalamus–pituitary–adrenal (HPA) axis dysregulation in various disorders. Given recent findings of sex differences in HPA axis function in psychosis, the current study investigated differences in HV in male and female first episode psychosis (FEP) patients and controls and the interaction of HV with the cortisol awakening response (CAR) and symptoms.

Methods

Fifty-eight patients with a diagnosis of FEP (39 men, 19 women) and 27 healthy community controls (15 men, 12 women) underwent structural magnetic resonance imaging (MRI) on a 1.5 T scanner. Hippocampal volume was determined using previously established segmentation protocols. Saliva samples for cortisol assessment were collected at 0, 30 and 60 min after awakening. Psychotic symptoms were assessed with the Scale for Assessment of Positive Symptoms (SAPS), the Scale for Assessment of Negative Symptoms (SANS) and the Global Assessment of Functioning (GAF) scale.

Results

Male patients had significantly smaller left and right HVs compared to male controls, which appeared to be secondary to global brain volume differences. However, even when controlling for overall brain size, male patients showed smaller HV compared to female patients. The CAR was significantly lower in male patients compared to male controls and female patients. Only in male patients, smaller left HV was significantly associated with a blunted CAR, and smaller HV bilaterally was related to positive psychotic symptoms and lower levels of functioning.

Conclusions

We propose that reduced hippocampal volume and an attenuated cortisol awakening response are related markers of increased stress vulnerability in male psychosis patients and that both contribute to the unfavorable clinical picture in men.

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We examined sex differences in neurobiological markers of stress in psychosis.

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Hippocampal volume and cortisol levels to awakening are reduced in male patients.

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Male first episode psychosis patients show markers of high stress vulnerability.

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Neurobiological deficits relate to poor outcome in male but not female patients.

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The neural-diathesis stress model of schizophrenia is particularly valid for men.

How much do we know about schizophrenia and how well do we know it? Evidence from the Schizophrenia Library

BACKGROUND

True findings about schizophrenia remain elusive; many findings are not replicated and conflicting results are common. Well-conducted systematic reviews have the ability to make robust, generalizable conclusions, with good meta-analyses potentially providing the closest estimate of the true effect size. In this paper, we undertake a systematic approach to synthesising the available evidence from well-conducted systematic reviews on schizophrenia.

METHOD

Reviews were identified by searching Medline, EMBASE, CINAHL, Current Contents and PsycINFO. The decision to include or exclude reviews, data extraction and quality assessments were conducted in duplicate. Evidence was graded as high quality if reviews contained large samples and robust results; and as moderate quality if reviews contained imprecision, inconsistency, smaller samples or study designs that may be prone to bias.

RESULTS

High- and moderate-quality evidence shows that numerous psychosocial and biomedical treatments are effective. Patients have relatively poor cognitive functioning, and subtle, but diverse, structural brain alterations, altered electrophysiological functioning and sleep patterns, minor physical anomalies, neurological soft signs, and sensory alterations. There are markers of infection, inflammation or altered immunological parameters; and there is increased mortality from a range of causes. Risk for schizophrenia is increased with cannabis use, pregnancy and birth complications, prenatal exposure to Toxoplasma gondii, childhood central nervous system viral infections, childhood adversities, urbanicity and immigration (first and second generation), particularly in certain ethnic groups. Developmental motor delays and lower intelligence quotient in childhood and adolescence are apparent.

CONCLUSIONS

We conclude that while our knowledge of schizophrenia is very substantial, our understanding of it remains limited.

Toxic Stress: Effects, Prevention and Treatment

Children who experience early life toxic stress are at risk of long-term adverse health effects that may not manifest until adulthood. This article briefly summarizes the findings in recent studies on toxic stress and childhood adversity following the publication of the American Academy of Pediatrics (AAP) Policy Report on the effects of toxic stress. A review of toxic stress and its effects is described, including factors of vulnerability, resilience, and the relaxation response. An integrative approach to the prevention and treatment of toxic stress necessitates individual, community and national focus.

Evidence-based psychotherapy for the prevention and treatment of first-episode psychosis

The aim of psychotherapy among individuals at clinical high risk (CHR) for psychosis is to prevent transition to full-blown psychosis. Psychotherapy in individuals with a first-episode psychosis (FEP) aims to reduce relapse rates. Remission of (pre-) psychotic symptoms, psychosocial functioning, quality of life, comorbid disorders and self-esteem are also important outcomes in individuals at CHR and with FEP. Antipsychotics, Qmega-3-Fatty acids and psychotherapy have been found to be effective in CHR for most of these aims. Thereby psychotherapy presents a better benefit/risk ratio than antipsychotic medication. The most evidence-based intervention is cognitive-behavioral therapy (CBT). Psychotherapy is mostly offered to FEP patients within specialized early intervention services (including assertiveness community treatment and antipsychotic medication). Thereby, CBT is effective for positive symptoms and family intervention is particularly effective for the prevention of relapses. We introduce the principles of CBT for psychosis and suggest adaptions for individuals at CHR and FEP. We conclude that the needs of young people at CHR and with FEP are best met by specially designed, low threshold outpatient clinical services, which include intensive psychotherapy treatment. A number of countries have implemented early detection and intervention services based on this model, while the implementation within in Germany is still marginal.

Interplay between childhood physical abuse and familial risk in the onset of psychotic disorders

BACKGROUND

Childhood abuse is considered one of the main environmental risk factors for the development of psychotic symptoms and disorders. However, this association could be due to genetic factors influencing exposure to such risky environments or increasing sensitivity to the detrimental impact of abuse. Therefore, using a large epidemiological case-control sample, we explored the interplay between a specific form of childhood abuse and family psychiatric history (a proxy for genetic risk) in the onset of psychosis.

METHODS

Data were available on 172 first presentation psychosis cases and 246 geographically matched controls from the Aetiology and Ethnicity of Schizophrenia and Other Psychoses study. Information on childhood abuse was obtained retrospectively using the Childhood Experience of Care and Abuse Questionnaire and occurrence of psychotic and affective disorders in first degree relatives with the Family Interview for Genetic Studies.

RESULTS

Parental psychosis was more common among psychosis cases than unaffected controls (adjusted OR = 5.96, 95% CI: 2.09-17.01, P = .001). Parental psychosis was also associated with physical abuse from mothers in both cases (OR = 3.64, 95% CI: 1.06-12.51, P = .040) and controls (OR = 10.93, 95% CI: 1.03-115.90, P = .047), indicative of a gene-environment correlation. Nevertheless, adjusting for parental psychosis did not measurably impact on the abuse-psychosis association (adjusted OR = 3.31, 95% CI: 1.22-8.95, P = .018). No interactions were found between familial liability and maternal physical abuse in determining psychosis caseness.

CONCLUSIONS

This study found no evidence that familial risk accounts for associations between childhood physical abuse and psychotic disorder nor that it substantially increases the odds of psychosis among individuals reporting abuse.

Prevalence and impact of childhood abuse in people with a psychotic illness. Data from the second Australian National Survey of Psychosis

Child abuse has been associated with risk of mental illness, including schizophrenia and other psychotic disorders and, among those with mental illness, with a more severe clinical profile. Using an extensively characterised and epidemiologically representative sample of 1825 Australians with a psychotic illness aged 18-64 years and in contact with mental health services, we estimated the proportion of individuals with psychotic disorders who self-reported child abuse and examined its relationship with clinical and other characteristics. The prevalence of child abuse in this nationally representative sample of people with psychotic illness was 30.6%. Women were almost three times more likely to report child abuse compared to males (OR, 2.8, 95% CI 2.3-3.4). When adjusted for age at interview and socio-economic status, there was no significant relationship between self-reported child abuse and type of psychosis or course of illness. Participants with child abuse were significantly more likely to have subjective thought disorder, lifetime suicide attempt and premorbid personality disorder (females only) and anxiety (males only). Our findings demonstrate that child abuse is relatively common across the range of psychotic disorders, with an elevated risk for women in particular, compounding the already high burden associated with psychotic illness. Clinicians need to inquire routinely about child abuse in order to develop appropriate treatment plans tailored to individual needs.

Brain derived Neurotropic Factor (BDNF) is associated with childhood abuse but not cognitive domains in first episode psychosis

BACKGROUND

The Brain-derived Neurotrophic Factor (BDNF) modulates cognitive processes and is associated with increased risk of schizophrenia. Childhood trauma (CT) is frequent in patients with psychosis and severely affects course and outcome.

AIMS

We investigated the hypothesis that BDNF is associated with both CT and cognitive deficits in a sample of first-episode psychosis (FEP) cases and unaffected controls.

METHOD

Participants with FEP and healthy controls were recruited between August 2008 and July 2011 from South London, UK. Childhood traumatic events were detected using the Childhood Experience of Care and Abuse Questionnaire (CECA-Q). Neuropsychological data were also collected. BDNF plasma levels were measured from fasting blood samples.

RESULTS

Data were available on 87 FEP patients and 152 controls. Our results showed a significant effect of separation (F=5.5; df=1,115; p=.02), physical (F=4.7; df=1, 118; p=.03) and sexual abuse (F=5.4; df=1,117; p=.02) on BDNF levels with lower levels among those who experienced the traumatic event compared to those who did not. Physical abuse predicted lower plasma levels of BDNF (β=-.30; p=.03) whereas sexual and/or physical abuse showed a trend (β=-.26; p=.06) in FEP patients but not in unaffected controls. No association between BDNF plasma levels and cognitive functions was found among patients with FEP and controls.

CONCLUSION

Our findings suggest the possible involvement of BDNF in the onset of first-episode psychosis in individuals exposed to early trauma and propose BDNF as a potential clinical biomarker to detect the detrimental effects of CT on human brain plasticity.

The relation between bullying and subclinical psychotic experiences and the influence of the bully climate of school classes

This study aims to examine the association between the bully climate of school classes and the prevalence of subclinical psychotic experiences among students who are involved in bullying (either as bully or as victim). Data were derived from the Dutch health behavior in school-aged children survey of 2005, a nationally representative cross-sectional study with a total of 5,509 adolescents between the age of 12 and 16. The data were analyzed using a multilevel regression analysis. The study revealed that both bullying and being bullied in school classes was associated with an increased level of subclinical psychotic experiences. The bully climate of a school class moderates this effect, i.e., the higher risk for bully-victims on subclinical psychotic experiences was less strong in classes with a higher percentage of classmates involved in bullying. Thus, bully climate has to be taken into account when studying the psychological experiences associated with being bullied.

Associations between specific psychotic symptoms and specific childhood adversities are mediated by attachment styles: an analysis of the National Comorbidity Survey

Accumulated evidence over the past decade consistently demonstrates a relationship between childhood adversity and psychosis in adulthood. There is some evidence of specific associations between childhood sexual abuse and hallucinations, and between insecure attachment and paranoia. Data from the National Comorbidity Survey were used in assessing whether current attachment styles influenced the association between adverse childhood experiences and psychotic symptoms in adulthood. Hallucinations and paranoid beliefs were differentially associated with sexual abuse (rape and sexual molestation) and neglect, respectively. Sexual abuse and neglect were also associated with depression. The relationship between neglect and paranoid beliefs was fully mediated via anxious and avoidant attachment. The relationship between sexual molestation and hallucinations was independent of attachment style. The relationship between rape and hallucinations was partially mediated via anxious attachment; however this effect was no longer present when depression was included as a mediating variable. The findings highlight the importance of addressing and understanding childhood experiences within the context of current attachment styles in clinical interventions for patients with psychosis.

Identifying gene-environment interactions in schizophrenia: contemporary challenges for integrated, large-scale investigations

Recent years have seen considerable progress in epidemiological and molecular genetic research into environmental and genetic factors in schizophrenia, but methodological uncertainties remain with regard to validating environmental exposures, and the population risk conferred by individual molecular genetic variants is small. There are now also a limited number of studies that have investigated molecular genetic candidate gene-environment interactions (G × E), however, so far, thorough replication of findings is rare and G × E research still faces several conceptual and methodological challenges. In this article, we aim to review these recent developments and illustrate how integrated, large-scale investigations may overcome contemporary challenges in G × E research, drawing on the example of a large, international, multi-center study into the identification and translational application of G × E in schizophrenia. While such investigations are now well underway, new challenges emerge for G × E research from late-breaking evidence that genetic variation and environmental exposures are, to a significant degree, shared across a range of psychiatric disorders, with potential overlap in phenotype.

History of childhood adversity is positively associated with ventral striatal dopamine responses to amphetamine

RATIONALE

Childhood exposure to severe or chronic trauma is an important risk factor for the later development of adult mental health problems, such as substance abuse. Even in nonclinical samples of healthy adults, persons with a history of significant childhood adversity seem to experience greater psychological distress than those without this history. Evidence from rodent studies suggests that early life stress may impair dopamine function in ways that increase risks for drug abuse. However, the degree to which these findings translate to other species remains unclear.

OBJECTIVES

This study was conducted to examine associations between childhood adversity and dopamine and subjective responses to amphetamine in humans.

METHODS

Following intake assessment, 28 healthy male and female adults, aged 18-29 years, underwent two consecutive 90-min positron emission tomography studies with high specific activity [(11)C]raclopride. The first scan was preceded by intravenous saline; the second by amphetamine (AMPH 0.3 mg/kg).

RESULTS

Consistent with prior literature, findings showed positive associations between childhood trauma and current levels of perceived stress. Moreover, greater number of traumatic events and higher levels of perceived stress were each associated with higher ventral striatal dopamine responses to AMPH. Findings of mediation analyses further showed that a portion of the relationship between childhood trauma and dopamine release may be mediated by perceived stress.

CONCLUSIONS

Overall, results are consistent with preclinical findings suggesting that early trauma may lead to enhanced sensitivity to psychostimulants and that this mechanism may underlie increased vulnerability for drug abuse.

Stress, schizophrenia and bipolar disorder

The role of stress in precipitating psychotic episodes in schizophrenia and bipolar disorder has long been acknowledged. However, the neurobiological mechanism/s of this association have remained elusive. Current neurodevelopmental models of psychosis implicate early dysfunction in biological systems regulating hypothalamic-pituitary-adrenal axis and immune function, with long-term effects on the development of the brain networks responsible for higher order cognitive processes and stress reactivity in later life. There is also increasing evidence of childhood trauma in psychosis, and its impact on the development of brain systems regulating stress. These findings are emerging in the context of a new era of epigenetic methods facilitating the study of environmental effects on gene expression. The evidence is thus converging: exposure to stress at critical periods in life may be an important factor in the development of the brain dysfunction that represents psychosis vulnerability, rather than merely interacting with an independent 'biological vulnerability' to manifest in psychosis.

Impact of childhood adversity on the onset and course of subclinical psychosis symptoms--results from a 30-year prospective community study

The study objective was to examine childhood adversity in association with intra-individual changes and inter-individual differences in subclinical psychosis in a representative community cohort over a 30-year period of observation. We analyzed two psychosis syndromes derived from the SCL-90-R - schizotypal signs and schizophrenia nuclear symptoms - in 335 participants. Participants were repeatedly assessed between 1978 (around age 20) and 2008 (around age 50). We focused specifically on inter-individual differences and intra-individual changes over time by applying structural equation modeling, generalized linear models, and generalized estimating equations. Several weak inter-individual differences revealed that increased schizotypal signs are related to various childhood adversities, such as being repeatedly involved in fights and parents having severe conflicts among themselves. We also found a significant positive association between schizotypal signs and the total number of adversities a subject experienced. This pointed toward a modest dose-response relationship. The intra-individual change in schizotypal signs over time was rather weak, although some adjustment did occur. In contrast, inter-individual schizophrenia nuclear symptoms were mainly unrelated to childhood adversity. However, some striking intra-individual changes in distress were noted over time, especially those linked with severe punishment and the total adversity score. In conclusion, we have confirmed previous positive findings about the association between childhood adversity and subsequent subclinical psychosis symptoms: An increase in adversity is weakly related to an increase of the psychosis symptom load. However, depending on the kind of adversity experienced the psychosis symptom load decreases gradually in adult life.

Differential neurodevelopmental trajectories in patients with early-onset bipolar and schizophrenia disorders

Schizophrenia and bipolar disorders share not only clinical features but also some risk factors such as genetic markers and childhood adversity, while other risk factors such as urbanicity and obstetric complications seem to be specific to schizophrenia. An intriguing question is whether the well-established abnormal neurodevelopment present in many children and adolescents who eventually develop schizophrenia is also present in bipolar patients. The literature on adult bipolar patients is controversial. We report data on a subgroup of patients with pediatric-onset psychotic bipolar disorder who seem to share some developmental trajectories with patients with early-onset schizophrenia. These early-onset psychotic bipolar patients have low intelligence quotient, more neurological signs, reduced frontal gray matter at the time of their first psychotic episode, and greater brain changes than healthy controls in a pattern similar to early-onset schizophrenia cases. However, patients with early-onset schizophrenia seem to have more social impairment, developmental abnormalities (eg, language problems), and lower academic achievement in childhood than early-onset bipolar patients. We suggest that some of these abnormal developmental trajectories are more related to the phenotypic features (eg, early-onset psychotic symptoms) of these 2 syndromes than to categorically defined Diagnostic and Statistical Manual of Mental Disorders disorders.

Catechol-O-methyltransferase (COMT) genotype moderates the effects of childhood trauma on cognition and symptoms in schizophrenia

The interaction of genetic and environmental factors may affect the course and development of psychotic disorders. We examined whether the effects of childhood trauma on cognition and symptoms in schizophrenia were moderated by the Catechol-O-methyltransferase (COMT) Val(158)Met polymorphism, a common genetic variant known to affect cognition and prefrontal dopamine levels. Participants were 429 schizophrenia/schizoaffective cases from the Australian Schizophrenia Research Bank (ASRB). Cognitive performance was assessed using the Repeatable Battery for Assessment of Neuropsychological Status (RBANS), Controlled Oral Word Association Test (COWAT), Letter Number Sequencing (LNS) test, and the Wechsler Test of Adult Reading (WTAR). Hierarchical regression was used to test the main effects and additive interaction effects of genotype and childhood trauma in the domains of physical abuse, emotional abuse, and emotional neglect, on cognition and symptom profiles of clinical cases. Consistent with previous findings, COMT Val homozygotes performed worse on cognitive measures in the absence of childhood adversity. In addition, a significant interaction between COMT genotype and physical abuse was associated with better executive function in Val homozygotes, relative to those of the same genotype with no history of abuse. Finally, the severity of positive symptoms was greater in Met carriers who had experienced physical abuse, and the severity of negative symptoms in Met carriers was greater in the presence of emotional neglect. These results suggest that the possible epigenetic modulation of the expression of the COMT Val(158)Met polymorphism and consequent effects on cognition and symptoms in schizophrenia, with worse outcomes associated with adverse childhood experiences in Met carriers.

The social defeat hypothesis of schizophrenia: an update

According to the social defeat (SD) hypothesis, published in 2005, long-term exposure to the experience of SD may lead to sensitization of the mesolimbic dopamine (DA) system and thereby increase the risk for schizophrenia. The hypothesis posits that SD (ie, the negative experience of being excluded from the majority group) is the common denominator of 5 major schizophrenia risk factors: urban upbringing, migration, childhood trauma, low intelligence, and drug abuse. The purpose of this update of the literature since 2005 is to answer 2 questions: (1) What is the evidence that SD explains the association between schizophrenia and these risk factors? (2) What is the evidence that SD leads to sensitization of the mesolimbic DA system? The evidence for SD as the mechanism underlying the increased risk was found to be strongest for migration and childhood trauma, while the evidence for urban upbringing, low intelligence, and drug abuse is suggestive, but insufficient. Some other findings that may support the hypothesis are the association between risk for schizophrenia and African American ethnicity, unemployment, single status, hearing impairment, autism, illiteracy, short stature, Klinefelter syndrome, and, possibly, sexual minority status. While the evidence that SD in humans leads to sensitization of the mesolimbic DA system is not sufficient, due to lack of studies, the evidence for this in animals is strong. The authors argue that the SD hypothesis provides a parsimonious and plausible explanation for a number of epidemiological findings that cannot be explained solely by genetic confounding.

Prevalence of bullying victimisation amongst first-episode psychosis patients and unaffected controls

BACKGROUND

Despite increasing evidence suggesting that childhood maltreatment is significantly associated with psychosis, the specific role of bullying in the onset of psychotic disorders is still unclear. This study aimed to examine whether bullying was more prevalent amongst individuals presenting to services for the first time with a psychotic disorder than in unaffected community controls.

METHODS

Data on exposure to bullying, psychotic symptoms, cannabis use and history of conduct disorder were collected cross-sectionally from 222 first-presentation psychosis cases and 215 geographically-matched controls. Bullying victimisation was assessed retrospectively as part of the Brief Life Events schedule. Logistic regression was used to examine associations between exposure to bullying and case-control status, while controlling for potential confounders.

RESULTS

Psychosis cases were approximately twice as likely to report bullying victimisation when compared to controls. No significant interactions between bullying and either gender or cannabis use were found. Controls reporting being a victim of bullying were approximately twice as likely to also report at least one psychosis-like symptom.

CONCLUSIONS

Our results extend previous research by suggesting that bullying victimisation may contribute to vulnerability to develop a psychotic disorder in some individuals.

The relevance of self-esteem and self-schemas to persecutory delusions: a systematic review

BACKGROUND

Self-esteem is frequently targeted in psychological approaches to persecutory delusions (PD). However, its precise role in the formation and maintenance of PD is unclear and has been subject to a number of theories: It has been hypothesized that PD function to enhance self-esteem, that they directly reflect negative conceptualizations of the self, that self-esteem follows from the perceived deservedness of the persecution (poor-me versus bad-me-paranoia) and that the temporal instability of self-esteem is relevant to PD. In order to increase our understanding of the relevance of self-esteem to PD, this article systematically reviews the existing research on self-esteem in PD in the light of the existing theories.

METHODS

We performed a literature search on studies that investigated self-esteem in PD. We included studies that either investigated self-esteem a) within patients with PD or compared to controls or b) along the continuum of subclinical paranoia in the general population. We used a broad concept of self-esteem and included paradigms that assessed implicit self-esteem, specific self-schemas and dynamic aspects of self-esteem.

RESULTS

The literature search identified 317 studies of which 52 met the inclusion criteria. The reviewed studies consistently found low global explicit self-esteem and negative self-schemas in persons with PD. The studies therefore do not support the theory that PD serve to enhance self-esteem but underline the theory that they directly reflect specific negative self-schemas. There is evidence that low self-esteem is associated with higher perceived deservedness of the persecution and that PD are associated with instable self-esteem. Only few studies investigated implicit self-esteem and the results of these studies were inconsistent.

CONCLUSIONS

We conclude by proposing an explanatory model of how self-esteem and PD interact from which we derive clinical implications.

Childhood adversities in relation to psychiatric disorders

Substantial evidence has documented that adverse childhood experiences exert deleterious effects on mental health. It is less clear to what extent specific maltreatment during specific developmental periods may vary between disorders rather than increasing vulnerability for any particular disorder. The present comparison of characteristics of childhood adversity (type and frequency of adversity, developmental period) between major depressive disorder (MDD), borderline personality disorder (BPD), schizophrenia, and psychiatrically healthy subjects examined how effects of adverse childhood experiences vary between disorders. Patients generally reported more adverse events than healthy subjects. Irrespective of diagnosis, emotional maltreatment was substantial in all patients. BPD was characterized by marked increase of adversities across age relative to MDD and schizophrenia. Fifty-six percent of BPD, 40% of MDD and 18% of schizophrenia cases experienced a significant degree of early childhood adversity. Stress pattern (type and time) varied between diagnoses, but not for patients with significant early adversities. Regression analyses confirmed early experiences as a predictor of BPD, but not of MDD and schizophrenia. Prepubescent experiences predicted affective and traumatic symptoms in BPD, and moderated the association with symptoms in MDD. Results indicate a dose-effect with differential impact of adverse childhood experiences in BPD, MDD, and schizophrenia, while early maltreatment beyond a certain degree affects mental health independent of diagnosis.

Neuropsychological functions and visual contrast sensitivity in schizophrenia: the potential impact of comorbid posttraumatic stress disorder (PTSD)

Previous studies have revealed a high prevalence of posttraumatic stress disorder (PTSD) in patients with other severe mental disorders, including schizophrenia. However, the neuropsychological and psychophysical correlates of comorbid PTSD are less exactly defined. The purpose of the present study was to assess immediate and delayed memory, attention, visuospatial skills, language, and basic visual information processing in patients with schizophrenia with or without PTSD. We recruited 125 patients with schizophrenia and 70 healthy controls matched for visual acuity, age, gender, education, and socioeconomic status. Twenty-one of patients with schizophrenia exhibited comorbid PTSD. We administered the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and visual contrast sensitivity tasks for low spatial/high temporal frequency (0.3 cycle/degree and 18 Hz) and high spatial/low temporal frequency (10 cycles/degree and 1Hz) sinusoidal gratings. All patients were clinically stable and received antipsychotic medications. Results revealed that relative to healthy controls, patients with schizophrenia exhibited significant and generalized neuropsychological dysfunctions and reduced visual contrast sensitivity, which was more pronounced at low spatial/high temporal frequency. When we compared schizophrenia patients with and without PTSD, we found that patients with comorbid PTSD displayed lower scores for RBANS attention, immediate and delayed memory, and visuospatial scores. Schizophrenia patients with or without PTSD displayed similar visual contrast sensitivity. In conclusion, comorbid PTSD in schizophrenia may be associated with worse neuropsychological functions, whereas it does not affect basic visual information processing.

Cognitive interventions targeting brain plasticity in the prodromal and early phases of schizophrenia

Several important paradigm shifts have occurred in the field of schizophrenia treatment, including an increased focus on early detection, the development of preemptive interventions, and the view of schizophrenia as a neurodevelopmental disease characterized by decreased efficiency and abnormal connectivity in cortical and subcortical neural networks. In this review, we briefly describe some of the neural impairments that contribute to the development of schizophrenia, with an emphasis on the impact of stress and trauma on cognitively vulnerable neural systems. We then present current data on two behavioral interventions that target these critical risk factors and that aim to preempt the onset of schizophrenia in vulnerable individuals or improve the clinical course in recent-onset schizophrenia: cognitive therapy and computerized cognitive training.

EMDR in Psychosis: Guidelines for Conceptualization and Treatment

A significant proportion of clients with psychosis have experienced childhood trauma and suffer from comorbid posttraumatic stress disorder. Research indicates that exposure to distressing early life events plays an important role in the emergence and persistence of psychotic symptoms—either directly or indirectly. The Two Method Approach of EMDR conceptualization and recent findings on reprocessing of psychosis-related imagery fit with the existing cognitive models of psychosis. This article presents a series of preliminary guidelines for conceptualizing EMDR treatment in psychosis, which are based on both theory and clinical experience and are illustrated with case examples. Several obstacles and related treatment strategies for using EMDR in psychosis are described. EMDR in psychosis can very well be combined with other standard interventions such as psychotropic medication and cognitive behavioral therapy.