Gene-environment interaction in vulnerability to schizophrenia: findings from the Finnish Adoptive Family Study of Schizophrenia

Sex-related differences in parental rearing patterns in young adults with bipolar disorder

The aim of this study was to examine the parenting characteristics of young patients with bipolar disorder (BD) and explore the sex differences. The parental rearing pattern of young patients with BD was measured and compared with the healthy control of young adults. The EMBU scale was used to assess parental rearing patterns. Patients with BD reported significantly higher scores in the punishment and severity index, as well as of the rejection and denial index, but lower scores in the warmth & affectionate index in the paternal rearing pattern, compared with healthy controls. In addition, patients scored higher on the punishment and severity index and rejection and patterns index in maternal rearing patterns. More importantly, we found significant sex differences in maternal rearing patterns (pBonferroni < 0.05). Specifically, in the maternal rearing patterns, male patients had higher scores on the favoring index than male controls, whereas female patients had lower scores on the warmth & affectionate index than female controls. This study shows significant differences in parental rearing patterns between patients and control subjects. Male patients were overprotective by their mothers and female patients were overlooked by their mothers during upbringing.

Delusional disorder with depression and history of early trauma: A case report

BACKGROUND

The case report supports the recent findings regarding the correlation of posttraumatic stress disorder (PTSD) and schizophrenia. The report accomplished the following objectives: (1) To present a case of an adult female manifesting with somatic type of delusion (foul body odor) and history of PTSD; (2) To discuss the biopsychosocial factors, psychodynamics and management of the patient; and (3) To differentiate delusional disorder from schizophrenia according to recent studies. Schizophrenia and delusional disorder have certain defining features that separate the two. However, at times it may be difficult to actually classify one from the other. A psychiatrist must be able to carefully examine and assess the history of the patient, helping them share early life experiences of past traumatic events. The early past traumatic experiences and life events greatly influence the predisposition of a patient to develop schizophrenia. However, people with schizophrenia were known to underreport their trauma experience.

CASE SUMMARY

This is a case of a young adult female diagnosed with delusional disorder with a history of PTSD and associated depression. The patient manifested with somatic type of delusion with a fixed false belief that a foul body odor was coming from her underarms.

CONCLUSION

Developing a therapeutic alliance is vital in achieving therapy goals through empathy, support and warmth between the patient and physician. History of PTSD predisposes patients with schizophrenia to develop depressive disorders as a comorbidity.

Psychotic disorders in young adults with perinatally acquired HIV: a UK case series

BACKGROUND

Increasing numbers of children with perinatally acquired HIV (PaHIV) are transitioning into adult care. People living with behaviourally acquired HIV are known to be at more risk of psychosis than uninfected peers. Young adults living with PaHIV face numerous risk factors; biological: lifelong exposure to a neurotrophic virus, antiretroviral medication and immune dysfunction during brain development, and environmental; social deprivation, ethnicity-related discrimination, and migration-related issues. To date, there is little published data on the prevalence of psychotic illness in young people growing up with PaHIV.

METHODS

We conducted a retrospective case note review of all individuals with PaHIV aged over 18 years registered for follow up at a dedicated clinic in the UK (n = 184).

RESULTS

In total, 12/184 (6.5%), median age 23 years (interquartile range 21-26), had experienced at least one psychotic episode. The presentation and course of the psychotic episodes experienced by our cohort varied from short-lived symptoms to long term illness and nine (75%) appear to have developed a severe and enduring mental illness requiring long term care.

CONCLUSION

The prevalence of psychosis in our cohort was clearly above the lifetime prevalence of psychosis in UK individuals aged 16-34 years, which has been reported to be 0.5-1.0%. This highlights the importance of clinical vigilance regarding the mental health of young people growing up with PaHIV and the need to integrate direct access to mental health services within the HIV centres providing medical care.

Dysfunctional family functioning in high socioeconomic status families as a risk factor for the development of psychiatric disorders in adoptees: the Finnish Adoptive Family Study of Schizophrenia

PURPOSE

Earlier findings indicate that socioeconomic status (SES) of family associates with family functioning. This study examined the impacts of family functioning and genetic risk for schizophrenia on psychiatric morbidity of adoptees in families of high SES (HSES) and low SES (LSES).

METHODS

The study population is a subgroup of the Finnish Adoptive Family Study of Schizophrenia. Of the adoptees, 152 had high genetic risk for schizophrenia spectrum disorders (HR) and 151 adoptees had low risk (LR). Of the adoptees, 185 (HR = 94, LR = 91) were raised in high-SES (HSES) families and 118 (HR = 58, LR = 60) in low-SES (LSES) families. The family SES was determined by the occupational status of the main provider of the family. The functioning of adoptive families was assessed based on Global Family Ratings (GFRs) and psychiatric disorders on DSM-III-R criteria.

RESULTS

In the HSES families, the psychiatric morbidity of the adoptees was emphasized by HR (OR = 4.28, CI 2.14-8.56) and dysfunctional family processes (OR = 6.44, CI 2.75-15.04). In the LSES families, the adoptees´ psychiatric morbidity was almost significantly increased by HR (OR = 2.10, CI 0.99-4.45), but not by dysfunctional family processes (OR = 1.33, CI 0.53-3.34).

CONCLUSIONS

This study showed that in HSES families, dysfunctional family processes and HR for schizophrenia increased the likelihoods for the development of psychiatric disorders in adoptees. The results can be utilized in identifying risk factors in the development of psychiatric disorders and focusing preventative strategies on risk groups with acknowledging the importance of family functioning.

Parenting in the Context of the Child: Genetic and Social Processes

The focus on the role of parenting in child development has a long-standing history. When measures of parenting precede changes in child development, researchers typically infer a causal role of parenting practices and attitudes on child development. However, this research is usually conducted with parents raising their own biological offspring. Such research designs cannot account for the effects of genes that are common to parents and children, nor for genetically influenced traits in children that influence how they are parented and how parenting affects them. The aim of this monograph is to provide a clearer view of parenting by synthesizing findings from the Early Growth and Development Study (EGDS). EGDS is a longitudinal study of adopted children, their birth parents, and their rearing parents studied across infancy and childhood. Families (N = 561) were recruited in the United States through adoption agencies between 2000 and 2010. Data collection began when adoptees were 9 months old (males = 57.2%; White 54.5%, Black 13.2%, Hispanic/Latinx 13.4%, Multiracial 17.8%, other 1.1%). The median child age at adoption placement was 2 days (M = 5.58, SD = 11.32). Adoptive parents were predominantly in their 30s, White, and coming from upper-middle- or upper-class backgrounds with high educational attainment (a mode at 4-year college or graduate degree). Most adoptive parents were heterosexual couples, and were married at the beginning of the project. The birth parent sample was more racially and ethnically diverse, but the majority (70%) were White. At the beginning of the study, most birth mothers and fathers were in their 20s, with a mode of educational attainment at high school degree, and few of them were married. We have been following these family members over time, assessing their genetic influences, prenatal environment, rearing environment, and child development. Controlling for effects of genes common to parents and children, we confirmed some previously reported associations between parenting, parent psychopathology, and marital adjustment in relation to child problematic and prosocial behavior. We also observed effects of children's heritable characteristics, characteristics thought to be transmitted from parent to child by genetic means, on their parents and how those effects contributed to subsequent child development. For example, we found that genetically influenced child impulsivity and social withdrawal both elicited harsh parenting, whereas a genetically influenced sunny disposition elicited parental warmth. We found numerous instances of children's genetically influenced characteristics that enhanced positive parental influences on child development or that protected them from harsh parenting. Integrating our findings, we propose a new, genetically informed process model of parenting. We posit that parents implicitly or explicitly detect genetically influenced liabilities and assets in their children. We also suggest future research into factors such as marital adjustment, that favor parents responding with appropriate protection or enhancement. Our findings illustrate a productive use of genetic information in prevention research: helping parents respond effectively to a profile of child strengths and challenges rather than using genetic information simply to identify some children unresponsive to current preventive interventions.

Traumatic experiences in childhood and adolescence: a meta-analysis of prospective studies assessing risk for psychosis

Evidence of the association between traumatic experiences and psychosis are uncertain with respect to temporal order, clinical outcomes and the role of the age and genetic liability. The aim of the present meta-analysis was to explore the temporal relationship between the development of psychosis and traumatic exposure using prospective studies and to examine the role of moderation factors on overall effect sizes. Studies were identified by searching Embase-Ovid, PsycINFO (EBSCO), Pubmed, Scopus, Web of Science databases, and yielded an initial total of 9016 papers, leaving finally 23 after the screening process. Three sets of meta-analyses estimated the risk of developing psychotic experiences or full clinical psychosis by having experienced maltreatment by an adult or bullying by peers or parental death, using the random-effects model. Bullying by peers (OR = 2.28 [1.64, 4.34]), maltreatment by an adult (OR = 2.20 [1.72, 2.81]) and parental death (OR = 1.24 [1.06, 1.44]) all increased the risk of psychosis. Moderator analysis showed that negative effects of bullying were detected especially in those with genetic liability for psychosis and exposure to multiple trauma types; studies with higher prevalence of males showed a stronger risk for those exposed to parental death. No significant meta-regression was found between the risk of developing a full clinical psychosis or a psychotic experience. Lack of studies hampered the results about the age of trauma occurrence. The cumulative effect of being bullied from peers and experiencing other adversities during childhood and/or adolescence, together with genetic liability for psychosis, appears to confer the highest risk for developing psychotic symptoms later in life.

An attachment perspective on the risk for psychosis: Clinical correlates and the predictive value of attachment patterns and mentalization

BACKGROUND

In a longitudinal design, the present study examined: (a) the nature of attachment patterns and reflective functioning (RF) in individuals at ultra-high risk for psychosis (UHR); (b) the association between RF and subclinical psychotic symtoms; and (c) the psychosis-predictive value of attachment patterns, RF, and the interaction between these factors.

METHOD

The sample comprised 57 UHR subjects and 53 clinical controls (non-UHR). UHR subjects were followed over a mean period of 14 months (SD = 2.7; range 11-19), during which time 11.5% developed psychosis. Attachment patterns and RF were measured. Hierarchical logistic regression was used to examine the predictive value of variables in the transition to psychosis.

RESULTS

At baseline, significant differences were found between groups in secure attachment patterns and RF. RF was negatively associated with the attenuated psychotic symptoms described by the Unusual Thought Content/Delusional Ideas, Suspiciousness/Persecutory Ideas, and Disorganized Communication subscales. Moreover, poor mentalization was related to an increased likelihood of developing a psychotic disorder (OR = 0.427, 95% CI [0.188, 0.970]); conversely, no predictive effects of the attachment variables and their interaction with RF on the transition to psychosis were found. Notably, an optimal threshold value of RF = 1.25 was found to distinguish UHR subjects who made the transition to psychosis from those who did not develop this pathology.

CONCLUSION

The results suggest that aberrant mentalizing patterns can predict the development of psychosis. Clinical implications of these results for the development of preventive treatments are discussed.

Using an adoption design to test genetically based differences in risk for child behavior problems in response to home environmental influences

Differential susceptibility theory (DST) posits that individuals differ in their developmental plasticity: some children are highly responsive to both environmental adversity and support, while others are less affected. According to this theory, "plasticity" genes that confer risk for psychopathology in adverse environments may promote superior functioning in supportive environments. We tested DST using a broad measure of child genetic liability (based on birth parent psychopathology), adoptive home environmental variables (e.g., marital warmth, parenting stress, and internalizing symptoms), and measures of child externalizing problems (n = 337) and social competence (n = 330) in 54-month-old adopted children from the Early Growth and Development Study. This adoption design is useful for examining DST because children are placed at birth or shortly thereafter with nongenetically related adoptive parents, naturally disentangling heritable and postnatal environmental effects. We conducted a series of multivariable regression analyses that included Gene × Environment interaction terms and found little evidence of DST; rather, interactions varied depending on the environmental factor of interest, in both significance and shape. Our mixed findings suggest further investigation of DST is warranted before tailoring screening and intervention recommendations to children based on their genetic liability or "sensitivity."

Evidence for interaction between genetic liability and childhood trauma in the development of psychotic symptoms

PURPOSE

Whilst childhood trauma (CT) is a known risk factor across the spectrum of psychosis expression, little is known about possible interplay with genetic liability.

METHODS

The TwinssCan Study collected data in general population twins, focussing on expression of psychosis at the level of subthreshold psychotic experiences. A multilevel mixed-effects linear regression analysis was performed including 745 subjects to assess the interaction between genetic liability and CT. The Symptom Checklist-90 (SCL-90-R) score of the co-twin was used as an indirect measure of genetic liability to psychopathology, while the Childhood Trauma Questionnaire Short-Form (CTQ-SF) was used to assess CT in the domains of physical, emotional and sexual abuse, as well as physical and emotional neglect. The Community Assessment of Psychic Experience (CAPE) questionnaire was used to phenotypically characterize psychosis expression.

RESULTS

In the model using the CAPE total score, the interaction between CT and genetic liability was close to statistical significance (χ² = 5.6, df = 2, p = 0.06). Analyses of CAPE subscales revealed a significant interaction between CT and genetic liability (χ² = 8.8, df = 2, p = 0.012) for the CAPE-negative symptoms subscale, but not for the other two subscales (i.e. positive and depressive).

CONCLUSION

The results suggest that the impact of CT on subthreshold expression of psychosis, particularly in the negative subdomain, may be larger in the co-presence of significant genetic liability for psychopathology.

Interaction of genetic vulnerability to schizophrenia and family functioning in adopted-away offspring of mothers with schizophrenia

OBJECTIVE

The aim of this study was to examine the association of family functioning to psychiatric disorders of adoptees with and without genetic vulnerability to schizophrenia.

METHODS

The data is based on the Finnish Adoptive Family Study of Schizophrenia. The study sample consisted of 346 adoptive families, of which 175 adoptees had high (HR) and 171 low (LR) genetic risk for schizophrenia. DSM-III-R was used for diagnostic criteria. Family functioning was assessed using the Global Family Ratings. Childhood adversities covered early parental divorce and death occurring before 18 years of age of the adoptees.

RESULTS

Approximately two thirds of the adoptees had lived in families with mildly dysfunctional processes (30%) or dysfunctional processes (28.4%). An increased likelihood for psychiatric disorders of the adoptees was related to dysfunctional family processes both in HR (OR = 4.8, 95% CI 2-11.4) and LR (OR = 2.6, 95% CI 1.1-6.3) adoptees, but not to early parental death or divorce.

CONCLUSIONS

The risk for psychiatric disorders was increased for adoptees in families with dysfunctional processes, especially for those adoptees with genetic vulnerability to schizophrenia. These results emphasize the importance of policies and practices that aim to strengthen and support family functioning.

Polygenic Risk Score for Schizophrenia and Face-Processing Network in Young Adulthood

Development of schizophrenia relates to both genetic and environmental factors. Functional deficits in many cognitive domains, including the ability to communicate in social interactions and impaired recognition of facial expressions, are common for patients with schizophrenia and might also be present in individuals at risk of developing schizophrenia. Here we explore whether an individual's polygenic risk score (PRS) for schizophrenia is associated with the degree of interregional similarities in blood oxygen level-dependent (BOLD) signal and gray matter volume of the face-processing network and whether the exposure to early adversity moderates this association. A total of 90 individuals (mean age 22 years, both functional and structural data available) were used for discovery analyses, and 211 individuals (mean age 26 years, structural data available) were used for replication of the structural findings. Both samples were drawn from the Northern Finland Birth Cohort 1986. We found that the degree of interregional similarities in BOLD signal and gray matter volume vary as a function of PRS; lowest interregional correlation (both measures) was observed in individuals with high PRS. We also replicated the gray matter volume finding. We did not find evidence for an interaction between early adversity and PRS on the interregional correlation of BOLD signal and gray matter volume. We speculate that the observed group differences in PRS-related correlations in both modalities may result from differences in the concurrent functional engagement of the face-processing regions over time, eg, via differences in exposure to social interaction with other people.

Exploring the moderating effects of dopaminergic polymorphisms and childhood adversity on brain morphology in schizophrenia-spectrum disorders

Genetic and environmental etiologies may contribute to schizophrenia and its associated neurobiological profile. We examined the interaction between dopaminergic polymorphisms, childhood adversity and diagnosis (schizophrenia/schizoaffective disorder) on dopamine-related brain structures. Childhood adversity histories and structural MRI data were obtained from 249 (153 schizophrenia/schizoaffective, 96 controls) participants registered in the Australian Schizophrenia Research Bank. Polymorphisms in DRD2 and COMT were genotyped and a dopaminergic risk allelic load (RAL) was calculated. Regression analysis was used to test the main and interaction effects of RAL, childhood adversity and diagnosis on volumes of dopamine-related brain structures (caudate, putamen, nucleus accumbens, dorsolateral prefrontal cortex and hippocampus). A schizophrenia/schizoaffective diagnosis showed significant main effects on bilateral hippocampus, left dorsolateral prefrontal cortex and bilateral putamen volumes. RAL showed a significant main effect on left putamen volumes. Furthermore, across the whole sample, a significant two-way interaction between dopaminergic RAL and childhood adversity was found for left putamen volumes. No brain structure volumes were predicted by a three-way interaction that included diagnosis. Our finding suggests the left putamen may be particularly sensitive to dopaminergic gene-environment interactions regardless of diagnosis. However, larger studies are needed to assess whether these interactions are more or less pronounced in those with schizophrenia/schizoaffective disorders.

Parental style and Cloninger's model in psychosis

Parental style and Cloninger's dimensions are associated with psychosis, but it is still unclear whether temperament, character and parenting variables are linked to specific psychotic symptoms. This study extends previous research exploring these issues. 78 patients with psychosis and 156 control subjects were recruited. Parental style was evaluated using the Measure of Parental Style. Temperament and character were evaluated using the Temperament and Character Inventory-Revised. Psychotic symptoms were assessed using the Positive and Negative Syndrome Scale. T-tests, correlations and moderation and mediation analyses were performed. Patients reported dysfunctional parenting and had higher scores for harm avoidance (HA) and self transcendence (ST), and lower scores for self directedness (SD) and cooperativeness (CO) than controls. Maternal indifference, abuse and overcontrol were correlated with positive symptoms (PS). Novelty seeking (NS), reward dependence, SD, CO were correlated with PS; HA and ST were correlated with negative symptoms. After adjusting for age, gender and family history of psychopathology lower CO partially mediated the relationship between maternal abuse and PS; the positive NS-maternal abuse interaction was associated with PS. Different parenting and personality variables may be associated with different psychotic symptoms. NS and CO may be part of a pathway between maternal abuse and PS.

Mapping early environment using communication deviance: A longitudinal study of maternal sensitivity toward 6-month-old children

Communication deviance (CD) reflects features of the content or manner of a person's speech that may confuse the listener and inhibit the establishment of a shared focus of attention. The construct was developed in the context of the study of familial risks for psychosis based on hypotheses regarding its effects during childhood. It is not known whether parental CD is associated with nonverbal parental behaviors that may be important in early development. This study explored the association between CD in a cohort of mothers (n = 287) at 32 weeks gestation and maternal sensitivity with infants at 29 weeks in a standard play procedure. Maternal CD predicted lower overall maternal sensitivity (B = -.385; p < .001), and the effect was somewhat greater for sensitivity to infant distress (B = -.514; p < .001) than for sensitivity to nondistress (B = -.311; p < .01). After controlling for maternal age, IQ and depression, and for socioeconomic deprivation, the associations with overall sensitivity and sensitivity to distress remained significant. The findings provide new pointers to intergenerational transmission of vulnerability involving processes implicated in both verbal and nonverbal parental behaviors.

Formal thought disorders: from phenomenology to neurobiology

Formal thought disorder (FTD) is present in most psychiatric disorders and in some healthy individuals. In this Review, we present a comprehensive, integrative, and multilevel account of what is known about FTD, covering genetic, cellular, and neurotransmitter effects, environmental influences, experimental psychology and neuropsychology, brain imaging, phenomenology, linguistics, and treatment. FTD is a dimensional, phenomenologically defined construct, which can be clinically subdivided into positive versus negative and objective versus subjective symptom clusters. Because FTDs have been traditionally linked to schizophrenia, studies in other diagnoses are scarce. Aetiologically, FTD is the only symptom under genetic influence in schizophrenia as shown in linkage studies, but familial communication patterns (allusive thinking) have also been associated with the condition. Positive FTDs are related to synaptic rarefication in the glutamate system of the superior and middle lateral temporal cortices. Cortical volume of the left superior temporal gyrus is decreased in patients with schizophrenia who have positive FTD in structural MRI studies and shows reversed hemispheric (right more than left) activation in functional MRI experiments during speech production. Semantic network dysfunction in positive FTD has been demonstrated in experiments of indirect semantic hyperpriming (reaction time). In acute positive FTD, antipsychotics are effective, but a subgroup of patients have treatment-resistant, chronic, positive or negative FTD. Specific psychotherapy as treatment for FTD has not yet been developed. With this solid data on the pathogenesis of FTD, we can now implement clinical studies to treat this condition.

Rethinking Thought Disorder

It has been 30 years since Holzman introduced a special issue of the Schizophrenia Bulletin entitled “Thought Disorder in Schizophrenia.” He pointed out in his Editor’s Introduction that in contrast to the explosion of interest at that time in the biological aspects of schizophrenia, there were important areas of study that represented “... relatively neglected aspects of the psychopathology of schizophrenia, namely the varieties of thinking disorders (emphasis added) characteristic of schizophrenic patients and their possible underlying mechanisms.” Perhaps presciently, he ended his introduction by expressing hope that the articles included in that issue would lead to further intensive study of the cognitive (emphasis added) dysfunctions in schizophrenia. There has, indeed, been extensive research conducted in further understanding cognitive dysfunctions in schizophrenia, but considerably less so in understanding thought disorder.

Relation between psychotic symptoms, parental care and childhood trauma in severe mental disorders

A relation between different types of parental care, trauma in childhood and psychotic symptoms in adulthood has been proposed. The nature of this association is not clear and if it is more related to psychotic disorders per se or to a cluster of symptoms such as positive psychotic symptoms remains undefined. We have analysed the presence of childhood trauma using the CTQ scale and types of parental care using the PBI scale in three groups of subjects: borderline personality disorder patients (n=36), first psychotic episode patients (n=61) and healthy controls (n=173). Positive psychotic symptomatology was assessed with the CAPE scale. General linear models were used to study the relation between positive psychotic symptomatology and variables of interest. BPD patients had the highest rate of any kind of trauma, followed by FEP patients. We found a positive relationship between psychotic symptomatology and the existence of trauma in childhood in all groups. Moreover, an affectionless control rearing style was directly associated with the existence of trauma. Furthermore, subjects with trauma presented less probability of having an optimal parenting style in childhood. The relation between psychotic symptoms and trauma remained statistically significant after adjusting for other variables including parental rearing style. There seems to be a link between trauma in childhood and psychotic symptomatology across different populations independently of psychiatric diagnosis. Taking into account that there is an association between trauma and psychosis and that trauma is a modifiable factor, clinicians should pay special attention to these facts.

Thought Disorder in Schizophrenia and Bipolar Disorder Probands, Their Relatives, and Nonpsychiatric Controls

Thought disorder (TD) has long been associated with schizophrenia (SZ) and is now widely recognized as a symptom of mania and other psychotic disorders as well. Previous studies have suggested that the TD found in the clinically unaffected relatives of SZ, schizoaffective and bipolar probands is qualitatively similar to that found in the probands themselves. Here, we examine which quantitative measures of TD optimize the distinction between patients with diagnoses of SZ and bipolar disorder with psychotic features (BP) from nonpsychiatric controls (NC) and from each other. In addition, we investigate whether these same TD measures also distinguish their respective clinically unaffected relatives (RelSZ, RelBP) from controls as well as from each other. We find that deviant verbalizations are significantly associated with SZ and are co-familial in clinically unaffected RelSZ, but are dissociated from, and are not co-familial for, BP disorder. In contrast, combinatory thinking was nonspecifically associated with psychosis, but did not aggregate in either group of relatives. These results provide further support for the usefulness of TD for identifying potential non-penetrant carriers of SZ-risk genes, in turn enhancing the power of genetic analyses. These findings also suggest that further refinement of the TD phenotype may be needed in order to be suitable for use in genetic studies of bipolar disorder.

A Set-Based Mixed Effect Model for Gene-Environment Interaction and Its Application to Neuroimaging Phenotypes

Imaging genetics is an emerging field for the investigation of neuro-mechanisms linked to genetic variation. Although imaging genetics has recently shown great promise in understanding biological mechanisms for brain development and psychiatric disorders, studying the link between genetic variants and neuroimaging phenotypes remains statistically challenging due to the high-dimensionality of both genetic and neuroimaging data. This becomes even more challenging when studying gene-environment interaction (G×E) on neuroimaging phenotypes. In this study, we proposed a set-based mixed effect model for gene-environment interaction (MixGE) on neuroimaging phenotypes, such as structural volumes and tensor-based morphometry (TBM). MixGE incorporates both fixed and random effects of G×E to investigate homogeneous and heterogeneous contributions of multiple genetic variants and their interaction with environmental risks to phenotypes. We discuss the construction of score statistics for the terms associated with fixed and random effects of G×E to avoid direct parameter estimation in the MixGE model, which would greatly increase computational cost. We also describe how the score statistics can be combined into a single significance value to increase statistical power. We evaluated MixGE using simulated and real Alzheimer's Disease Neuroimaging Initiative (ADNI) data, and showed statistical power superior to other burden and variance component methods. We then demonstrated the use of MixGE for exploring the voxelwise effect of G×E on TBM, made feasible by the computational efficiency of MixGE. Through this, we discovered a potential interaction effect of gene ABCA7 and cardiovascular risk on local volume change of the right superior parietal cortex, which warrants further investigation.

Inner Speech and Clarity of Self-Concept in Thought Disorder and Auditory-Verbal Hallucinations

Eighty patients and thirty controls were interviewed using one interview that promoted personal disclosure and another about everyday topics. Speech was scored using the Thought, Language and Communication scale (TLC). All participants completed the Self-Concept Clarity Scale (SCCS) and the Varieties of Inner Speech Questionnaire (VISQ). Patients scored lower than comparisons on the SCCS. Low scores were associated the disorganized dimension of TD. Patients also scored significantly higher on condensed and other people in inner speech, but not on dialogical or evaluative inner speech. The poverty of speech dimension of TD was associated with less dialogical inner speech, other people in inner speech, and less evaluative inner speech. Hallucinations were significantly associated with more other people in inner speech and evaluative inner speech. Clarity of self-concept and qualities of inner speech are differentially associated with dimensions of TD. The findings also support inner speech models of hallucinations.

Neglect and hereditary risk: Their relative contribution to schizophrenia with negative symptomatology

BACKGROUND

There is evidence that genetic and environmental stressors contribute to the genesis of schizophrenia. However, the relevant impact of each factor remains unclear. We tested for an interactive effect between childhood neglect and family history of serious mental illness. Data were further analyzed for a possible connection to type of schizophrenic symptoms.

SAMPLING/METHODS

Data for the study are taken from the medical records of 641 patients with schizophrenia from a large state hospital in the northeastern United States. Clinical assessments were divided into positive and negative symptomatology through application of the Scale for the Assessment of Negative Symptoms (SANS), the Scale for the Assessment of Positive Symptoms (SAPS) and the Positive and Negative Syndrome Scale (PANSS). Detailed information about childhood neglect and family history of serious mental illness was obtained through Social Service Assessment interviews at intake and during hospital stay.

RESULTS

Among clients with no family history of mental illness, childhood neglect does not meaningfully affect the risk of negative versus positive schizophrenia. For clients with such history, on the other hand, neglect significantly raises the risk of schizophrenia with negative symptomatology.

CONCLUSION

Our central finding is that risk for negative symptoms of schizophrenia are elevated by childhood neglect combined with a history of serious mental illness within the family. This is the only report to combine schizophrenic symptoms, familial risk and childhood neglect to date. Implications for primary prevention and treatment are discussed.

'No man is an island'. Testing the specific role of social isolation in formal thought disorder

Recent work has focused on the role of the environment in psychosis with emerging evidence that specific psychotic experiences are associated with specific types of adversity. One risk factor that has been often associated with psychosis is social isolation, with studies identifying isolation as an important feature of prodromal psychosis and others reporting that social networks of psychotic patients are smaller and less dense than those of healthy individuals. In the present study, we tested a prediction that social isolation would be specifically associated with formal thought disorder. 80 patients diagnosed with psychosis-spectrum disorder and 30 healthy participants were assessed for formal thought disorder with speech samples acquired during an interview that promoted personal disclosure and an interview targeting everyday topics. Social isolation was significantly associated with formal thought disorder in the neutral interview and in the salient interview, even when controlling for comorbid hallucinations, delusions and suspiciousness. Hallucinations, delusions and suspiciousness were not associated with social isolation when formal thought disorder was controlled for. Formal thought disorder is robustly and specifically associated with social isolation. Social cognitive mechanisms and processes are discussed which may explain this relationship as well as implications for clinical practice and future research.

Wellbeing and resilience: mechanisms of transmission of health and risk in parents with complex mental health problems and their offspring--The WARM Study

The WARM study is a longitudinal cohort study following infants of mothers with schizophrenia, bipolar disorder, depression and control from pregnancy to infant 1 year of age.

BACKGROUND

Children of parents diagnosed with complex mental health problems including schizophrenia, bipolar disorder and depression, are at increased risk of developing mental health problems compared to the general population. Little is known regarding the early developmental trajectories of infants who are at ultra-high risk and in particular the balance of risk and protective factors expressed in the quality of early caregiver-interaction.

METHODS/DESIGN

We are establishing a cohort of pregnant women with a lifetime diagnosis of schizophrenia, bipolar disorder, major depressive disorder and a non-psychiatric control group. Factors in the parents, the infant and the social environment will be evaluated at 1, 4, 16 and 52 weeks in terms of evolution of very early indicators of developmental risk and resilience focusing on three possible environmental transmission mechanisms: stress, maternal caregiver representation, and caregiver-infant interaction.

DISCUSSION

The study will provide data on very early risk developmental status and associated psychosocial risk factors, which will be important for developing targeted preventive interventions for infants of parents with severe mental disorder.

TRIAL REGISTRATION

NCT02306551, date of registration November 12, 2014.

Association of adoptive child's thought disorders and schizophrenia spectrum disorders with their genetic liability for schizophrenia spectrum disorders, season of birth and parental Communication Deviance

Joint effects of genotype and the environment have turned out to be significant in the development of psychotic disorders. The purpose of the present study was to assess the association of an adoptive child׳s thought and schizophrenia spectrum disorders with genetic and environmental risk indicators and their interactions. A subgroup of the total sample used in the Finnish Adoptive Family Study was considered in the present study. The subjects were 125 adoptees at a high (n=53) or low (n=72) genetic risk of schizophrenia spectrum disorders and their adoptive parents. The risk factors evaluated were the adoptive child's genetic risk for schizophrenia spectrum disorders, winter or spring birth and parental Communication Deviance (CD). Thought disorders in the adoptees were assessed using the Thought Disorder Index and diagnoses were made according to DSM-III-R criteria. The adoptive child׳s Thought Disorder Index was only associated with parental Communication Deviance. The adoptive child's heightened genetic risk or winter or spring birth or parental CD or their interactions did not predict the adoptee's schizophrenia spectrum disorder. The results suggest that studies taking several risk indicators and their interactions into account may change views on the mutual significance of well-known risk factors.

A mentalization-based approach to the development of the therapeutic alliance in the treatment of schizophrenia

This article presents a clinical illustration of a mentalization-based approach to the development of a therapeutic alliance in the treatment of schizophrenia. A clinically focused overview of the attachment-based understanding of mentalization central to the mentalization-based treatment model is first provided. This is followed by a brief summary of the theory and evidence supporting the possible link between attachment disturbances and deficits of mental state understanding in schizophrenia. A case presentation then illustrates the application of core mentalization-based principles and interventions to enhance the therapeutic alliance by addressing disruptions of mentalization and reducing paranoia in the treatment of a patient with early course schizophrenia.

From adversity to psychosis: pathways and mechanisms from specific adversities to specific symptoms

PURPOSE

Although there is considerable evidence that adversities in childhood such as social deprivation, sexual abuse, separation from parents, neglect and exposure to deviant parental communication are associated with psychosis in later life, most studies have considered broad diagnoses as outcomes. In this review we consider evidence for pathways between specific types of adversity and specific symptoms of psychosis.

METHODS

We present theoretical arguments for expecting some degree of specificity (although by no means perfect specificity) between different kinds of adversity and different symptoms of psychosis. We review studies that have investigated social-environmental risk factors for thought disorder, auditory-verbal hallucinations and paranoid delusions, and consider how these risk factors may impact on specific psychological and biological mechanisms.

RESULTS

Communication deviance in parents has been implicated in the development of thought disorder in offspring, childhood sexual abuse has been particularly implicated in auditory-verbal hallucinations, and attachment-disrupting events (e.g. neglect, being brought up in an institution) may have particular potency for the development of paranoid symptoms. Current research on psychological mechanisms underlying these symptoms suggests a number of symptom-specific mechanisms that may explain these associations.

CONCLUSIONS

Few studies have considered symptoms, underlying mechanisms and different kinds of adversity at the same time. Future research along these lines will have the potential to elucidate the mechanisms that lead to severe mental illness, and may have considerable clinical implications.

Parental communication and psychosis: a meta-analysis

BACKGROUND

Parental communication deviance (CD) has long been suggested as a potential risk factor for the development of psychosis and thought disorder in genetically sensitive offspring. However, the findings of the studies on the prevalence of CD in parents of psychotic patients have never been submitted to quantitative synthesis.

METHOD

PsycINFO was searched from January 1959 to January 2012 for studies on the prevalence of CD in parents of psychotic patients. This search was supplemented with the results from a much larger systematic search (PsycINFO, PubMed, EMBASE, and Web of Science) on childhood trauma and psychosis.

RESULTS

A total of 20 retrieved studies (n = 1753 parents) yielded a pooled g of large magnitude (0.97; 95% CI [0.76; 1.18]) with a significant amount of heterogeneity (Q = 33.63; P = .014; I (2) = 46.47). Subgroup and sensitivity analysis of methodological features (study's design, comparison group, diagnostic criteria, CD rating method, inter-rater reliability not reported, year of publication, and verbosity) and demographic characteristics (level of education or offspring's age) revealed that pooled effect size was stable and unlikely to have been affected by these features.

CONCLUSION

CD is highly prevalent in parents of psychotic offspring. This is discussed in the broader context of adoption and longitudinal studies that have reported a G × E interaction in the development of psychosis and thought disorder. A potential developmental mechanism is suggested to explain how CD may affect the developing offspring. The importance of further studies on CD and its potential value as a clinical concept are discussed.

Stability in MMPI among adoptees with high and low genetic risk for schizophrenia and with low Communication Deviance of their adoptive parents

Stability has been considered an important aspect of vulnerability to schizophrenia. The temporal stability of the scales in the Minnesota Multiphasic Personality Inventory (MMPI) was examined, using adoptees from the Finnish Adoptive Family Study of Schizophrenia. Adoptees who were high-risk (HR) offspring of biological mothers having a schizophrenia spectrum disorder (n=28) and low-risk (LR) controls (n=46) were evaluated using 15 MMPI scales at the initial assessment (HR, mean age 24 years; LR, mean age 23 years) and at the follow-up assessment after a mean interval of 11 years. Stability of the MMPI scales was also assessed in the groups of adoptees, assigned according to the adoptive parents'(n=44) communication style using Communication Deviance (CD) scale as an environmental factor. Initial Lie, Frequency, Correction, Psychopathic Deviate, Schizophrenia, Manifest Hostility, Hypomania, Phobias, Psychoticism, Religious Fundamentalism, Social Maladjustment, Paranoid Schizophrenia, Golden-Meehl Indicators, Schizophrenia Proneness and 8-6 scale scores significantly predicted the MMPI scores at the follow-up assessment indicating stability in the characteristics of thinking, affective expression, social relatedness and volition. Low CD in the family had an effect on the stabilization of personality traits such as social withdrawal and restricted affectivity assessed by Correction and Hostility.

A randomized trial of family focused therapy with populations at clinical high risk for psychosis: effects on interactional behavior

OBJECTIVE

This study investigated whether family focused therapy (FFT-CHR), an 18-session intervention that consisted of psychoeducation and training in communication and problem solving, brought about greater improvements in family communication than enhanced care (EC), a 3-session psychoeducational intervention, among individuals at clinical high risk for developing psychosis.

METHOD

This study was conducted within a randomized controlled trial across 8 sites. We examined 10-min problem-solving discussions at baseline and 6-month reassessment among 66 adolescents and young adults and their parents. Trained coders who were blind to treatment and time of assessment achieved high levels of interrater reliability when evaluating family discussions on categories of calm-constructive and critical-conflictual behavior.

RESULTS

Individuals at high risk and their family members who participated in FFT-CHR demonstrated greater improvement from baseline to 6-month reassessment in constructive communication and decreases in conflictual behaviors during family interactions than those in EC. Participants in FFT-CHR showed greater increases from baseline to 6 months in active listening and calm communication and greater decreases in irritability and anger, complaints and criticism, and off-task comments compared to participants in EC. These changes occurred equally in high-risk participants and their family members.

CONCLUSIONS

A 6-month family skills training treatment can bring about significant improvement in family communication among individuals at high risk for psychosis and their parents. Future studies should examine the association between enhancements in family communication and reduced risk for the onset of psychosis among individuals at high risk.

Development of liability syndromes for schizophrenia: where did they come from and where are they going?

Three decades after Paul Meehl proposed the term "schizotaxia" to describe a conceptual framework for understanding the liability to schizophrenia, Ming Tsuang et al. at Harvard University reformulated the concept as a clinical syndrome with provisional research criteria. The reformulated view relied heavily on more recent data showing that many non-psychotic, un-medicated biological relatives of individuals with schizophrenia showed difficulties in cognitive and other clinical functions that resembled those seen in their ill relatives. The reformulation raised questions about both whether and when liability could be assessed validly in the absence of psychosis, and about the extent to which symptoms of liability are reversible. Both questions bear on the larger issue of early intervention in schizophrenia. This article reviews the efforts of Tsuang et al. to conceptualize and validate schizotaxia as one such syndrome of liability. Towards this end, liability is considered first more generally as an outcome of interactive genetic and environmental factors. Liability is then considered in the context of endophenotypes as a concept that is both broader and is potentially more specific (and predictive) than many DSM or ICD diagnostic symptoms. Liability syndromes are then considered in the context of their proximity to illness, first by reviewing prodromal syndromes (which are more proximal), and then by considering schizotaxia, which, as it is currently formulated, is pre-prodromal and, therefore, less proximal. Finally, challenges to validation and future directions for research are considered.

Association of parental communication deviance with offspring's psychiatric and thought disorders. A systematic review and meta-analysis

Elevated number of parental Communication Deviance (CD) has been connected with psychiatric and thought disorders in their offspring. However, no earlier systematic efforts have been made to review this issue. The aim of this study was to survey the existing literature systematically and perform a meta-analysis of this association. A literature search for published and unpublished observational studies on the association of parental Communication Deviance with psychopathology in the offspring was conducted. Multiple electronic databases were searched (from 1960 to 2012) and the reference lists of the resulting publications were scanned. The findings were pooled using random effect meta-analysis. A total of 19 relevant papers were found and accessed. The results showed that a high level of parental CD is associated with schizophrenia spectrum disorders in the offspring. A large overall effect size (0.79) was found in the meta-analysis. No meta-analysis could be performed on the association of parental CD with an offspring's thought disorders, but the results suggest that such an association may exist. Parental Communication Deviance is associated with schizophrenia spectrum disorders in the offspring. High parental CD could be treated as an indicator of a risk of developing a schizophrenia spectrum disorder, at least among high-risk groups.

Introspection and schizophrenia: a comparative investigation of anomalous self experiences

This paper offers a comparative investigation of anomalous self-experiences common in schizophrenia (defined in Examination of Anomalous Self Experiences (EASE) instrument) and those of normal individuals in an intensely introspective orientation (early 20th-century "introspectionist" psychology). The latter represent a relatively pure manifestation of certain forms of exaggerated self-consciousness ("hyperreflexivity"), one facet of the disturbance of core- or minimal-self ("ipseity" disturbance) postulated as central in schizophrenia. Significant similarities with schizophrenia-like experience were found but important differences also emerged. Affinities included feelings of passivity, fading of self or world, and alienation from thoughts, feelings, or lived-body. Differences involved confusion between self and world and severe dislocation or erosion of first-person perspective, qualities unique to schizophrenia. The purpose is threefold: 1, place the putatively schizophrenic experiences of self-disorder in a broader, comparative context; 2, evaluate hypotheses concerning core processes in schizophrenia; 3, orient investigation of possible pathogenetic pathways as well as psychotherapeutic interventions.

Early trauma and familial risk in the development of the extended psychosis phenotype in adolescence

OBJECTIVE

Both genetic and environmental factors are thought to play a role in the development of psychotic outcomes; however, their respective contributions over time, including possible developmental interactions, remain largely unknown.

METHOD

The contribution of parental general and psychotic psychopathology as proxies of genetic risk to the development of subthreshold psychosis and its hypothesized interaction with childhood trauma were studied in a general population sample of 2230 adolescents, followed from age 10-16 years. Outcome measures were: i) level of psychotic experiences at age 16 years and ii) persistence of such experiences over the total follow-up period.

RESULTS

General parental psychopathology was associated with CAPE score (OR = 1.08; P < 0.043 for highest quintile) and suggestively predicted psychosis persistence (OR, 1.16; P < 0.072). Psychotic parental psychopathology was suggestively associated with CAPE score (OR, 2.25; P < 0.063 for highest quintile), predicted membership of the Persistent group (OR, 3.72; P < 0.039) and suggestively predicted membership of the Decreasing group (OR 2.04; P < 0.051). Childhood trauma was associated with CAPE score and with all developmental trajectories of subclinical psychosis. No evidence was found for an interaction between trauma and parental psychopathology.

CONCLUSION

The development and persistence of subthreshold psychotic symptoms may be conditional on non-interacting proxy genetic and environmental influences.

The stability of severe thought disorders and mature thinking

The aim of this study was to investigate whether severe formal thought disorders and mature thinking are stable among adoptees (=187) drawn from the Finnish adoptive family study of schizophrenia. A group of 93 adoptees genetically at high risk (HR) and 94 at low risk (LR) for schizophrenia were assessed blindly and reliably using the Index of Primitive Thought (IPT) and the Index of Integration (IOI). Two assessments of the IPT and the IOI were performed with the mean interval of 11 years. Comparisons of the IPT and the IOI mean scores were conducted both at baseline and at follow-up between adoptees at low and high genetic risk, gender, and psychiatric status. The main result was that the IOI as well as the IPT of the adoptees at the initial assessment predicted the IOI and the IPT estimated at follow-up, thus indicating the stability of severe formal thought disorders and mature thinking over time. The stability of IOI or IPT was not related to genetic risk, gender or psychiatric status or their interactions.

Clinical applications of schizophrenia genetics: genetic diagnosis, risk, and counseling in the molecular era

Schizophrenia is a complex neuropsychiatric disease with documented clinical and genetic heterogeneity, and evidence for neurodevelopmental origins. Driven by new genetic technologies and advances in molecular medicine, there has recently been concrete progress in understanding some of the specific genetic causes of this serious psychiatric illness. In particular, several large rare structural variants have been convincingly associated with schizophrenia, in targeted studies over two decades with respect to 22q11.2 microdeletions, and more recently in large-scale, genome-wide case-control studies. These advances promise to help many families afflicted with this disease. In this review, we critically appraise recent developments in the field of schizophrenia genetics through the lens of immediate clinical applicability. Much work remains in translating the recent surge of genetic research discoveries into the clinic. The epidemiology and basic genetic parameters (such as penetrance and expression) of most genomic disorders associated with schizophrenia are not yet well characterized. To date, 22q11.2 deletion syndrome is the only established genetic subtype of schizophrenia of proven clinical relevance. We use this well-established association as a model to chart the pathway for translating emerging genetic discoveries into clinical practice. We also propose new directions for research involving general genetic risk prediction and counseling in schizophrenia.

Major depression: a role for hippocampal neurogenesis?

Since its discovery in mammals, adult neurogenesis, the process of generating functional neurons from neural progenitor cells in the adult brain, has inspired numerous animal studies. These have revealed that adult neurogenesis is a highly regulated phenomenon. Enriched environment, exercise and learning for instance, are positive regulators while stress and age are major negative regulators. Stressful life events are not only shown to reduce adult neurogenesis levels but are also discussed to be a key element in the development of various neuropsychiatric disorders such as depression. Interestingly, altered monoaminergic brain levels resulting from antidepressant treatment are shown to have a strong reinforcing effect on adult neurogenesis. Additionally, disturbed adult neurogenesis, possibly resulting in a malfunctioning hippocampus, may contribute to the cognitive deficits and reduced hippocampal volumes observed in depressed patients. Hence, the question arises as to whether disturbed adult neurogenesis and the etiopathogenesis of depression are causally linked. In this chapter, we discuss the possible causal interrelation of disturbed adult neurogenesis and the etiopathogenesis of depression as well as the possibility that adult neurogenesis is not exclusively linked to depression but is also linked to other psychiatric disorders including schizophrenia and neurodegenerative diseases like Alzheimer's disease. Additionally, we look at the functional relevance of adult neurogenesis in different species, upon which we base our discussion as to whether adult neurogenesis could be causally linked to the development of certain brain disorders in humans, or whether it is only an epiphenomenon.

Epigenetic epidemiology in psychiatry: A translational neuroscience perspective

Accumulating evidence from the field of neuroscience indicates a crucial role for epigenetic regulation of gene expression in development and aging of nervous system and suggests that aberrations in the epigenetic machinery are involved in the etiology of psychiatric disorders. Epidemiologic evidence on epigenetics in psychiatry, however, is currently very sparsely available, but is consistent with a mediating role for epigenetic mechanisms in bringing together inherited and acquired risk factors into a neurodevelopmental etiological model of psychiatric disorders. Here, we review evidence from the epidemiological and neuroscience literature, and aim to converge the evidence into an etiological model of psychiatric disorders that encompasses environmental, genetic and epigenetic contributions. Given the dynamic nature of the epigenetic machinery and the potential reversibility of epigenetic modifications, future well-designed interdisciplinary and translational studies will be of key importance in order to identify new targets for prevention and therapeutic strategies.

Genetic vulnerability and premature death in schizophrenia spectrum disorders: a 28-year follow-up of adoptees in the Finnish Adoptive Family Study of Schizophrenia

BACKGROUND

Excess mortality is widely reported among schizophrenia patients, but rarely examined in adoption study settings.

AIM

We investigated whether genetic background plays a role in the premature death of adoptees with schizophrenia.

METHODS

Mortality among 382 adoptees in the Finnish Adoptive Family Study of Schizophrenia was monitored from 1977 to 2005 through the national causes-of-death register. The sample covered 190 adoptees with a high genetic risk of schizophrenia (HR) and 192 with a low risk (LR).

RESULTS

Overall mortality among the adoptees did not differ between the HR and LR groups, as 10% and 9% respectively had died during the follow-up, at mean ages of 45 and 46 years. Schizophrenia spectrum disorder was the most significant predictor of premature death in both groups, with dysfunction in the rearing family environment associated with mortality, unnatural deaths and suicides in the HR but not in the LR group. All the suicides involved HR cases.

CONCLUSIONS

Mortality among the adoptees was not related to genetic factors but to environmental ones. The association of unnatural deaths and suicides with dysfunction in the rearing environment among the HR adoptees may indicate that they had a greater genetically determined vulnerability to environmental effects than their LR counterparts. The genetic and rearing environments can be disentangled in this setting because the biological parents give the offspring their genes and the adoptive parents give them their rearing environment. Our findings add to knowledge of the factors associated with the premature death of adoptees in mid-life.

Communication Deviance in parents of families with adoptees at a high or low risk of schizophrenia-spectrum disorders and its associations with attributes of the adoptee and the adoptive parents

Communication Deviance (CD) in rearing parents is a known indicator of a psychopathology risk in the offspring, but the direction of the effects of these two factors on each other has remained an unresolved question. The purpose of the present study was to clarify this issue by assessing the relationship of CD in adoptive parents with certain attributes of the adoptee and adoptive parents themselves. The subjects were 109 adoptees at a high or low risk of schizophrenia-spectrum disorders and their adoptive parents. Communication Deviance was measured in individual, spouse and family Rorschach situations. Thought disorders in the adoptees were assessed using the Thought Disorder Index. The variability of CD in the adoptive parents in individual Rorschach situations was not significantly explained by any characteristics of the child. The variability in parental CD in family Rorschach situations was most closely associated with the characteristics of the parents themselves. The results strongly support the hypotheses that the frequency of Communication Deviance is an enduring trait rather than a fluctuating state and that frequent CD in parent's speech may impair the growing child's cognitive development and predispose him/her to schizophrenia-spectrum disorders.

Gene-environment interaction in psychological traits and disorders

There has been an explosion of interest in studying gene-environment interactions (GxE) as they relate to the development of psychopathology. In this article, I review different methodologies to study gene-environment interaction, providing an overview of methods from animal and human studies and illustrations of gene-environment interactions detected using these various methodologies. Gene-environment interaction studies that examine genetic influences as modeled latently (e.g., from family, twin, and adoption studies) are covered, as well as studies of measured genotypes. Importantly, the explosion of interest in gene-environment interactions has raised a number of challenges, including difficulties with differentiating various types of interactions, power, and the scaling of environmental measures, which have profound implications for detecting gene-environment interactions. Taking research on gene-environment interactions to the next level will necessitate close collaborations between psychologists and geneticists so that each field can take advantage of the knowledge base of the other.

The role of genetics in the etiology of schizophrenia

Schizophrenia is a complex genetic disorder manifesting combined environmental and genetic causation. Recently, genome-wide association experiments yielded remarkable new experimental evidence that is leading to a better understanding of the genetic models and the biological risk factors involved in schizophrenia. These studies have discovered uncommon copy number variations (mainly deletions) and common single nucleotide polymorphisms with alleles associated with schizophrenia. The aggregate data provide support for polygenic inheritance and for genetic overlap of schizophrenia with autism and with bipolar disorder. It is anticipated that the application of a myriad of tools from systems biology, in combination with biological functional experiments, will lead to a delineation of biological pathways involved in the pathophysiology of schizophrenia, and eventually to new therapies.

Epigenetic mediation of environmental influences in major psychotic disorders

The major psychotic disorders schizophrenia and bipolar disorder are etiologically complex involving both heritable and nonheritable factors. The absence of consistently replicated major genetic effects, together with evidence for lasting changes in gene expression after environmental exposures, is consistent with the concept that the biologic underpinnings of these disorders are epigenetic in form rather than DNA sequence based. Psychosis-associated environmental exposures, particularly at key developmental stages, may result in long-lasting epigenetic alterations that impact on the neurobiological processes involved in pathology. Although direct evidence for epigenetic dysfunction in both schizophrenia and bipolar disorder is still limited, methodological technologies in epigenomic profiling have advanced. This means that we are at the exciting stage where it is feasible to start investigating molecular modifications to DNA and histones and examine the mechanisms by which environmental factors can act upon the genome to bring about epigenetic changes in gene expression involved in the etiology of these disorders. Given the dynamic nature of the epigenetic machinery and potential reversibility of epigenetic modifications, the understanding of such mechanisms is of key relevance for clinical psychiatry and for identifying new targets for prevention and/or intervention.

Genetic association and post-mortem brain mRNA analysis of DISC1 and related genes in schizophrenia

Convergent evidence from genetic linkage, genetic association and biological studies implicates the Disrupted in schizophrenia 1 (DISC1) gene in the etiology and pathophysiology of schizophrenia. We conducted genetic association studies in matched case-control and family sample sets (N=117 families; N=210 case-control pairs), testing polymorphisms across DISC1 and DISC1 interacting genes: LIS1, NUDEL, FEZ1 and PDE4B. We found that DISC1 variants, particularly in the exon 9/intron 9/intron 10 region of the gene, may be associated with risk for schizophrenia in our sample population. There was no strong evidence for association with LIS1, NUDEL, FEZ1 and PDE4B. Gene-gene interaction analyses and mRNA quantification in post-mortem brains from schizophrenia patients and control subjects did not reveal significant differences.

Schizophrenia: genetics, prevention and rehabilitation

OBJECTIVE

Genetic factors are largely implicated in predisposing to schizophrenia. Environmental factors contribute to the onset of the disorder in individuals at increased genetic risk. Cognitive deficits have emerged as endophenotypes and potential therapeutic targets for schizophrenia because of their association with functional outcome. The aims of this review were to analyse the joint effect of genetic and environmental (G×E) factors on liability to schizophrenia and to investigate relationships between genes and cognitive endophenotypes focusing on practical applications for prevention and rehabilitation.

METHODS

Medline search of relevant studies published between 1990 and 2008.

RESULTS

In schizophrenia, examples of G×E interaction include the catechol-O-methyl transferase (COMT) (Val158Met) polymorphism, which was found to moderate the onset of psychotic manifestations in response to stress and to increase the risk for psychosis related to cannabis use, and neurodevelopmental genes such as AKT1 (serine-threonine kinase), brain-derived neurotrophic factor (BDNF), DTNBP1 (dysbindin) and GRM3 (metabotropic glutamate receptor 3), which were associated with development of schizophrenia in adulthood after exposure to perinatal obstetric complications. Neurocognitive deficits are recognised as core features of schizophrenia that facilitate the onset of the disorder and have a great impact on functional outcome. Neurocognitive deficits are also endophenotypes that have been linked to a variety of genes [COMT, neuregulin (NRG1), BDNF, Disrupted-In-Schizophrenia 1 (DISC1) and dysbindin] conferring susceptibility to schizophrenia. Recently, it has emerged that cognitive improvement during rehabilitation therapy was under control of COMT (Val158Met) polymorphism.

CONCLUSION

This review could indicate a pivotal role of psychiatric genetics in prevention and rehabilitation of schizophrenic psychoses.

The centrality of personal relationships in the creation and amelioration of mental health problems: the current interdisciplinary case

An interdisciplinary case is made for the centrality of personal relationships in the creation and amelioration of mental health problems. Taking the work of John Bowlby as a starting point, the article summarizes accumulating evidence from the past 50 years about the link between childhood adversity and adult mental health problems. Evidence is also reviewed about contemporary interpersonal impacts on adult mental health from natural social settings and in professional therapy. These empirical summaries are then discussed in the context of dominant trends in professional knowledge about bio-determinism within psychiatry and the emphasis upon models and techniques in professional and political advocates of the psychological therapies. It is concluded that the latter trends are diverting us from policies, which properly concede the importance of relationships for improving the mental health of the population.