Childhood trauma and schizotypy in non-clinical samples: A systematic review and meta-analysis

Time to put aside the false dichotomy between personality disorders and psychotic symptoms

Unlike internalizing and externalizing symptoms, psychotic symptoms (e.g., hallucinations, delusions) are manifestations of personality disorders (PDs) that are more controversial and poorly understood. This leaves clinicians with very little guidance for clinical practice, especially for diagnosis. What is more, most reviews have focused strictly on the links between psychotic symptoms and the categorically defined borderline PD, which contrasts with the growing movement that emphasizes a dimensional perspective (especially in psychology). Thus, the objectives of this critical review will be to (a) expose typical cases where PDs and psychotic symptoms might cooccur; (b) assess the state of scientific knowledge surrounding PD and psychotic symptoms; and (c) provide clinicians and researchers with recommendations to keep the field moving forward. We conclude that researchers and clinicians should move past the false "PD or psychosis" dichotomy since they often cooccur, avoid (as far as possible) making psychotic symptoms an exclusion criterion in PD research to enhance ecological validity, and consider dimensional PD diagnosis as a potential unifying solution to the dilemma posed by this cooccurrence.

The relationship between childhood trauma, psychotic symptoms, and cognitive schemas in patients with schizophrenia, their siblings, and healthy controls: results from the EU-GEI study

BACKGROUND

The relationship between childhood trauma (CT) and psychotic symptoms in patients with schizophrenia (SCZ), and subthreshold psychotic experiences in non-clinical populations is well-established. However, little is known about the relationship between subtypes of trauma and specific symptoms in patients, their siblings, and controls. It is also not clear which variables mediate the relationship between trauma and psychotic symptoms.

METHODS

Seven hundred and forty-two patients with SCZ, 718 of their unaffected siblings and 1039 controls from three EU-GEI sites were assessed for CT, symptom severity, and cognitive schemas about self/others. CT was assessed with the Childhood Trauma Questionnaire, and cognitive schemas were assessed by The Brief Core Schema Scale.

RESULTS

Patients with psychosis were affected by CT more than their siblings and controls in all domains. Childhood emotional abuse and neglect were more common in siblings than controls. CT was related to negative cognitive schemas toward self/others in patients, siblings, and controls. We found that negative schemas about self-mediated the relationship between emotional abuse and thought withdrawal and thought broadcasting. Approximately 33.9% of the variance in these symptoms was explained by the mediator. It also mediated the relationship between sexual abuse and persecutory delusions in SCZ.

CONCLUSIONS

Our findings suggest that childhood abuse and neglect are more common in patients with schizophrenia than their siblings and healthy controls, and have different impacts on clinical domains which we searched. The relationship between CT and positive symptoms seems to be mediated by negative cognitive schemas about self in schizophrenia.

Adolescent Stress-Induced Ventral Hippocampus Redox Dysregulation Underlies Behavioral Deficits and Excitatory/Inhibitory Imbalance Related to Schizophrenia

BACKGROUND AND HYPOTHESIS

Redox dysregulation has been proposed as a convergent point of childhood trauma and the emergence of psychiatric disorders, such as schizophrenia (SCZ). A critical region particularly vulnerable to environmental insults during adolescence is the ventral hippocampus (vHip). However, the impact of severe stress on vHip redox states and their functional consequences, including behavioral and electrophysiological changes related to SCZ, are not entirely understood.

STUDY DESIGN

After exposing adolescent animals to physical stress (postnatal day, PND31-40), we explored social and cognitive behaviors (PND47-49), the basal activity of pyramidal glutamate neurons, the number of parvalbumin (PV) interneurons, and the transcriptomic signature of the vHip (PND51). We also evaluated the impact of stress on the redox system, including mitochondrial respiratory function, reactive oxygen species (ROS) production, and glutathione (GSH) levels in the vHip and serum.

STUDY RESULTS

Adolescent-stressed animals exhibited loss of sociability, cognitive impairment, and vHip excitatory/inhibitory (E/I) imbalance. Genome-wide transcriptional profiling unveiled the impact of stress on redox system- and synaptic-related genes. Stress impacted mitochondrial respiratory function and changes in ROS levels in the vHip. GSH and glutathione disulfide (GSSG) levels were elevated in the serum of stressed animals, while GSSG was also increased in the vHip and negatively correlated with sociability. Additionally, PV interneuron deficits in the vHip caused by adolescent stress were associated with oxidative stress.

CONCLUSIONS

Our results highlight the negative impact of adolescent stress on vHip redox regulation and mitochondrial function, which are partially associated with E/I imbalance and behavioral abnormalities related to SCZ.

Modelling the effects of the exposome score within the extended psychosis phenotype

It has been reported that cumulative measures of risk factors for psychosis might help to predict its development. However, it remains unknown as to whether these measures are also associated with the extended psychosis phenotype that refers to a continuum of features bridging subclinical symptoms with clinically relevant outcomes. In this study, we aimed to investigate the association of the exposome score (ES) with psychosis risk in a non-clinical population. A total of 1100 non-clinical adults (aged 18-35 years, 51.4% females) with a negative history of psychiatric treatment were recruited. The Prodromal Questionnaire-16 (PQ-16) was used to screen for psychosis risk. Self-reports were used to record environmental exposures. The ES was significantly higher in participants with the positive PQ-16 screening. Specifically, the prevalence of obstetric complications, non-right handedness, all categories of childhood trauma, and problematic cannabis use was significantly higher in this group of participants. A network analysis demonstrated that the ES was directly connected not only to items representing psychotic experiences ("paranoid thoughts", "a lack of control over own ideas or thoughts", "thought echo", and "being distracted by distant sounds") but also those covering depressive or anxiety symptoms ("uninterested in things used to enjoy" and "feeling anxious when meeting people for the first time"). In conclusion, the ES is associated with the extended psychosis phenotype, suggesting its potential to identify individuals who may benefit from further psychosis risk assessment. The ES appears to contribute to non-specific psychopathology, which may, in some cases, progress to psychosis.

Evaluation of reliability and validity of the Persian version of Peters et al. delusions inventory (PDI-40) in iranian non-clinical and clinical samples

BACKGROUND

Some individuals may manifest psychotic symptoms that do not fulfill the requisite clinical criteria for a formal diagnosis of psychosis. The assessment of susceptibility to delusions, encompassing both clinical and non-clinical cohorts, frequently makes use of the Peters et al. Delusions Inventory (PDI-40). This study aimed to evaluate the reliability and validity of the Persian version of Peters et al. Delusions Inventory (PDI-40) in Iranian non-clinical and clinical samples.

METHODS

The present study employed a cross-sectional, correlational design in 2020. A total of 1402 Iranian participants were recruited for the study, which consisted of three distinct stages. The first stage involved an Exploratory Factor Analysis (EFA) conducted on a non-clinical sample of 512 participants. The second stage comprising different non-clinical sample 764 participants to perform a Confirmatory Factor Analysis (CFA). In the third stage, a clinical sample of 126 psychotic patients was compared to a non-clinical sample. All participants completed the PDI-40, the Community Assessment of Psychotic Experiences (CAPE-42), and the Depression, Anxiety, and Stress Scale (DASS-21). The internal structure of PDI-40 was examined through the analysis of its factor structure using LISREL 8.8.

RESULTS

The EFA analysis unveiled nine components within Persian version of PDI-40. The CFA analysis demonstrated an excellent fit of the nine-factor structure of Persian PDI-40 to the data. The total score exhibited high internal reliability, as indicated by Cronbach's alpha coefficient of 0.92. Moreover, Persian PDI-40 exhibited satisfactory evidence of convergent validity, as significant correlations were observed between dimensions of PDI-40 and subscales of CAPE-42 and DASS-21. Lastly, findings indicated that psychotic participants scored higher than non-clinical participants in all components of the PDI-40(p < 0.05).

CONCLUSION

Persian version of the PDI-40 demonstrates strong reliability and validity for assessing delusion proneness in both non-clinical and clinical samples in Iran. The observed distinctions between psychotic and non-clinical participants underscore its potential as a valuable tool for discerning delusion proneness in diverse contexts.

Relationships between childhood trauma and dimensional schizotypy: A network analysis and replication

OBJECTIVES

Childhood trauma (CT) has been found to increase the risk of developing schizophrenia and other psychiatric disorders. Little is known regarding the complex interplay between CT, subclinical psychotic, and affective symptoms in the general population. This cross-sectional study adopted network analysis to examine such a complex relationship. We hypothesized that CT would show strong connections with schizotypy dimensions, and the high schizotypy subgroup would show a network with higher global strength compared with the low schizotypy subgroup.

METHODS

A total of 1813 college students completed a set of self-report questionnaires measuring CT, schizotypal features, bipolar traits, and depressive symptoms. The subscales of these questionnaires were used as nodes, and the partial correlations between nodes were used as edges to construct a network. Network Comparison Tests were used to investigate the differences between participants with high schizotypy and low schizotypy. An independent sample (n = 427) was used to examine the replicability of the results.

RESULTS

Findings from the main dataset showed that CT was closely connected with schizotypy and motivation, after controlling for the inter-relationships between all nodes in the network. Relative to the low schizotypy subgroup, the network of the high schizotypy subgroup showed higher global strength. The two subgroups did not differ in network structure. Network analysis using the replication dataset showed comparable global strength and network structure.

CONCLUSIONS

Our findings support specific links between CT and schizotypy dimensions in healthy youth populations, and such links appear to become stronger in those with high schizotypy.

Psychosocial factors associated with the risk of developing psychosis in a Mexican general population sample

Epidemiological evidence has linked an array of sociodemographic and psychosocial factors with an increased risk of developing psychosis. However, research in samples from low- and middle-income countries is still scarce. This study used a Mexican sample to explore (i) sociodemographic and psychosocial differences between individuals with and without a positive screen for Clinical High-Risk for psychosis (CHR), and (ii) sociodemographic and psychosocial factors associated with screening positive for CHR. The sample consisted of 822 individuals from the general population who completed an online survey. Of the participants, 17.3% (n = 142) met the CHR screening criteria. Comparisons between those who screened positive (CHR-positive group) and those who did not (Non-CHR group) showed that participants in the CHR-positive group were younger, had a lower educational level, and reported more mental health problems than the Non-CHR group. Furthermore, relative to the Non-CHR group, the CHR-positive group had a greater prevalence of medium/high risk associated with cannabis use, a higher prevalence of adverse experiences (bullying, intimate partner violence, and experiencing a violent or unexpected death of a relative or friend), as well as higher levels of childhood maltreatment, poorer family functioning, and more distress associated with the COVID-19 pandemic. Groups did not differ in sex, marital/relationship status, occupation, and socio-economic status. Finally, when examined in multivariate analyses, the variables associated with screening positive for CHR were: having an unhealthy family functioning (OR = 2.75, 95%CI 1.69-4.46), a higher risk associated with cannabis use (OR = 2.75, 95%CI 1.63-4.64), a lower level of education (OR = 1.55, 95%CI 1.003-2.54), having experienced a major natural disaster (OR = 1.94, 95%CI 1.18-3.16), having experienced a violent or unexpected death of a relative or friend (OR = 1.85, 95%CI 1.22-2.81), higher levels of childhood emotional abuse (OR = 1.88, 95%CI 1.09-3.25), physical neglect (OR = 1.68, 95%CI 1.08-2.61), and physical abuse (OR = 1.66, 95%CI 1.05-2.61), and higher COVID-related distress (OR = 1.10, 95%CI 1.01-1.20). An older age was a protective factor for screening positive for CHR (OR = 0.96, 95%CI 0.92-0.99). Overall, the findings highlight the importance of examining potential psychosocial contributors to psychosis vulnerability across different sociocultural contexts to delineate risk and protective processes relevant to specific populations and better target preventive intervention efforts.