Psychosocial stress and psychosis. A review of the neurobiological mechanisms and the evidence for gene-stress interaction

[Management of treatment resistance-Treatment-resistant schizophrenia]

Despite a very high prevalence and substantial impairments among affected individuals, treatment-resistant schizophrenia (TRS) has not been sufficiently researched in clinical research in the field of psychiatric disorders and the pathophysiology is still poorly understood. A better clinical and pathophysiological understanding of this heterogeneous and severely affected population of people with persistent symptoms in different domains is necessary in order not only to be able to intervene early but also to develop novel therapeutic strategies or individualized treatment approaches. This review article presents the state of the art criteria of the pharmacological TRS, neurobiological disease models and predictive factors for TRS as well as the phenomenon of pseudo-treatment resistance and the clinical management of TRS. In the future, not only the use of operationalized criteria and definitions of TRS in longitudinal studies and randomized-controlled trials (RCTs) are paramount, but also the observation of trajectories with the integration of multimodal longitudinal phenotyping and the longitudinal collection of clinical routine data in academic research, which will be possible in the newly created German Center for Mental Health (DZPG).

COVID-19 pandemic and emergency department visits for psychosis: Visit volume, restraint use, medication use, psychiatric hospitalization, and length of stay

BACKGROUND

Individuals with a schizophrenia spectrum disorder were at heightened risk for interruptions in psychiatric care during the coronavirus-19 (COVID 19) pandemic. There is limited work exploring the pandemic's impact on emergency department (ED) visit volume, use of restraint and parenteral medications, inpatient psychiatric (IP) hospitalization, and ED length of stay (LOS) among this population.

METHODS

We retrospectively examined 2134 ED visits with a billing code for psychosis between March 1, 2019-February 28, 2021. We used Poisson regression analysis to compare ED visit volume between the pandemic and pre-pandemic periods. Restraint use, parenteral antipsychotic or benzodiazepine use, IP hospitalization, and ED LOS were compared between the two periods using chi-square tests and independent samples t-tests.

RESULTS

Overall volume of psychosis-related ED visits during the pandemic did not differ significantly from the prior year. Rates of restraint use (16.2 % vs 11.6 %, p < .01), parenteral antipsychotic (22.6 % vs 14.9, p < .001), and parenteral benzodiazepine (22.3 % vs 16.3 %, p < .001) use were significantly higher during the pandemic. Fewer patients had an IP hospital disposition during the pandemic than the year prior (57.8 % vs. 61.9 %, p < .05). ED LOS was longer during the pandemic compared to pre-pandemic (28.37 h vs 20.26 h, p < .001).

CONCLUSIONS

Although the volume of psychosis-related ED visits remained constant, restraint and parenteral medication use rates were significantly higher during the pandemic. ED LOS increased but fewer ED visits resulted in IP hospitalization. These findings underscore the importance of planning for increased acuity of psychosis ED presentations during public health emergencies.

Validity of mental and physical stress models

Different stress models are employed to enhance our understanding of the underlying mechanisms and explore potential interventions. However, the utility of these models remains a critical concern, as their validities may be limited by the complexity of stress processes. Literature review revealed that both mental and physical stress models possess reasonable construct and criterion validities, respectively reflected in psychometrically assessed stress ratings and in activation of the sympathoadrenal system and the hypothalamic-pituitary-adrenal axis. The findings are less robust, though, in the pharmacological perturbations' domain, including such agents as adenosine or dobutamine. Likewise, stress models' convergent- and discriminant validity vary depending on the stressors' nature. Stress models share similarities, but also have important differences regarding their validities. Specific traits defined by the nature of the stressor stimulus should be taken into consideration when selecting stress models. Doing so can personalize prevention and treatment of stress-related antecedents, its acute processing, and chronic sequelae. Further work is warranted to refine stress models' validity and customize them so they commensurate diverse populations and circumstances.

Association between serum insulin-like growth factor 1 levels and the improvements of cognitive impairments in a subgroup of schizophrenia: Preliminary findings

BACKGROUND

Numerous studies have implicated abnormal insulin-like growth factor 1 (IGF-1) in the pathophysiology of schizophrenia, but findings have been inconsistent.

METHODS

We conducted a meta-analysis to compare IGF-1 levels in schizophrenia patients with healthy controls and explored factors contributing to variability between estimates. In an independent sample (58 chronic schizophrenia patients and 30 healthy controls), we investigated differences in IGF-1 levels among schizophrenia subgroups with distinct cognitive profiles, identified using k-means clustering based on five cognitive domains from The Repeatable Battery for the Assessment of Neuropsychological Status. Associations between serum IGF-1 levels and clinical and neurocognitive improvements were also examined.

RESULTS

The meta-analysis revealed significantly lower serum IGF-1 levels in schizophrenia patients compared to healthy controls, albeit with high heterogeneity. Medication status, BMI, and severity of negative symptoms were identified as potential contributors to this heterogeneity. In our independent study, antipsychotic treatment led to a significant increase in IGF-1 levels, and lower pre-treatment serum IGF-1 levels correlated with greater improvement in cognitive deficits, particularly in a subgroup with more severe cognitive symptoms.

CONCLUSIONS

Our findings support the "IGF-1 deficiency hypothesis" in the pathogenesis of schizophrenia. Further research is crucial to elucidate the role of IGF-1 in the cognitive impairments associated with schizophrenia.

Stress, Environment and Early Psychosis

Existing literature provides extended evidence of the close relationship between stress dysregulation, environmental insults, and psychosis onset. Early stress can sensitize genetically vulnerable individuals to future stress, modifying their risk for developing psychotic phenomena. Neurobiological substrate of the aberrant stress response to hypothalamic-pituitary-adrenal axis dysregulation, disrupted inflammation processes, oxidative stress increase, gut dysbiosis, and altered brain signaling, provides mechanistic links between environmental risk factors and the development of psychotic symptoms. Early-life and later-life exposures may act directly, accumulatively, and repeatedly during critical neurodevelopmental time windows. Environmental hazards, such as pre- and perinatal complications, traumatic experiences, psychosocial stressors, and cannabis use might negatively intervene with brain developmental trajectories and disturb the balance of important stress systems, which act together with recent life events to push the individual over the threshold for the manifestation of psychosis. The current review presents the dynamic and complex relationship between stress, environment, and psychosis onset, attempting to provide an insight into potentially modifiable factors, enhancing resilience and possibly influencing individual psychosis liability.

Bridging Neuroscience and Clinical Assessment in a Patient with Alcohol Use Disorder, Anxiety, and Trauma

This article presents a unique framework that combines insights from neuroscience with clinical assessment to evaluate individuals who have co-occurring alcohol use disorder, anxiety, and trauma. Through the use of a case study, the authors demonstrate the practical application of this framework and contextualize the relevant neurocircuitry associated with alcohol withdrawal, maladaptive fear and anxiety, and chronic stress. By integrating these perspectives, they provide a comprehensive approach for assessing and treating patients with complex psychiatric histories, particularly those presenting with anxiety symptoms, offering valuable insights for practitioners.

The Translational Future of Stress Neurobiology and Psychosis Vulnerability: A Review of the Evidence

Psychosocial stress is a well-established risk factor for psychosis, yet the neurobiological mechanisms underlying this relationship have yet to be fully elucidated. Much of the research in this field has investigated hypothalamic-pituitary-adrenal (HPA) axis function and immuno-inflammatory processes among individuals with established psychotic disorders. However, as such studies are limited in their ability to provide knowledge that can be used to develop preventative interventions, it is important to shift the focus to individuals with increased vulnerability for psychosis (i.e., high-risk groups). In the present article, we provide an overview of the current methods for identifying individuals at high-risk for psychosis and review the psychosocial stressors that have been most consistently associated with psychosis risk. We then describe a network of interacting physiological systems that are hypothesised to mediate the relationship between psychosocial stress and the manifestation of psychotic illness and critically review evidence that abnormalities within these systems characterise highrisk populations. We found that studies of high-risk groups have yielded highly variable findings, likely due to (i) the heterogeneity both within and across high-risk samples, (ii) the diversity of psychosocial stressors implicated in psychosis, and (iii) that most studies examine single markers of isolated neurobiological systems. We propose that to move the field forward, we require well-designed, largescale translational studies that integrate multi-domain, putative stress-related biomarkers to determine their prognostic value in high-risk samples. We advocate that such investigations are highly warranted, given that psychosocial stress is undoubtedly a relevant risk factor for psychotic disorders.

Neural response to rewards moderates the within-person association between daily positive events and positive affect during a period of stress exposure

Stress and neural responses to reward can interact to predict psychopathology, but the mechanisms of this interaction are unclear. One possibility is that the strength of neural responses to reward can affect the ability to maintain positive affect during stress. In this study, 105 participants completed a monetary reward task to elicit the reward positivity (RewP), an event-related potential sensitive to rewards. Subsequently, during a stressful period, participants reported on their affect nine times a day and on daily positive and negative events for 10 days. Even during heightened stress, experiencing more positive events was associated with increased positive affect. The RewP significantly moderated this association: Individuals with a larger RewP reported greater increases in positive affect when they experienced more positive events, relative to individuals with a smaller RewP. A blunted RewP might contribute to stress susceptibility by affecting how much individuals engage in positive emotion regulation during stress.

The impact of COVID-19 on acute psychiatric admissions for first and repeated episode psychosis

BACKGROUND

There is limited evidence of the longer-term impact of the COVID-19 pandemic on acute admissions for psychosis in the UK.

AIMS

We examined the impact of COVID-19 on rates of admissions for first and repeated episode psychosis, and changes in patient profile and seasonal patterns, over a period of 12 months.

METHOD

We conducted a retrospective case note review of all patients admitted with a primary psychosis (F20-29 ICD 10 diagnosis) to an NHS psychiatric inpatient unit. We compared the 12 months pre-COVID-19 period between 1 March 2019 and 28 February 2020, and the 12 months post-COVID-19 period between 1 March 2020 and 28 February 2021.

RESULTS

The results showed increase rates of admissions post-COVID-19 in both first and repeated episode psychosis, the patient profile had more females and older age in the repeated episode group, with increased employment rates. Combined group data for both pre- and post-COVID-19 periods showed an increased trend in spring and summer admissions, and even though not statistically significant, more pronounced post-COVID-19.

CONCLUSIONS

Our findings highlight the effect of the COVID-19 pandemic on acute psychosis admissions over a 12-month period. The results provide evidence for the 'stress-pathogenesis' in the context of genetic vulnerability in psychosis. Preventative strategies in the context of the 'stress-pathogenesis model', improved access to and responsiveness within NHS transformation efforts needs to be adjusted to fit local need and environmental changes.

Examining associations, moderators and mediators between childhood maltreatment, social functioning, and social cognition in psychotic disorders: a systematic review and meta-analysis

Childhood maltreatment (CM) has been related to social functioning and social cognition impairment in people with psychotic disorders (PD); however, evidence across different CM subtypes and social domains remains less clear. We conducted a systematic review and meta-analysis to quantify associations between CM, overall and its different subtypes (physical/emotional/sexual abuse, physical/emotional neglect), and domains of social functioning and social cognition in adults with PD. We also examined moderators and mediators of these associations. A PRISMA-compliant systematic search was performed on 24 November 2022 (PROSPERO CRD42020175244). Fifty-three studies (N = 13 635 individuals with PD) were included in qualitative synthesis, of which 51 studies (N = 13 260) with 125 effects sizes were pooled in meta-analyses. We found that CM was negatively associated with global social functioning and interpersonal relations, and positively associated with aggressive behaviour, but unrelated to independent living or occupational functioning. There was no meta-analytic evidence of associations between CM and social cognition. Meta-regression analyses did not identify any consistent moderation pattern. Narrative synthesis identified sex and timing of CM as potential moderators, and depressive symptoms and maladaptive personality traits as possible mediators between CM and social outcomes. Associations were of small magnitude and limited number of studies assessing CM subtypes and social cognition are available. Nevertheless, adults with PD are at risk of social functioning problems after CM exposure, an effect observed across multiple CM subtypes, social domains, diagnoses and illness stages. Maltreated adults with PD may thus benefit from trauma-related and psychosocial interventions targeting social relationships and functioning.

Evidence for increased DNA damage repair in the postmortem brain of the high stress-response group of schizophrenia

Background

Schizophrenia (SZ) is a disorder diagnosed by specific symptoms and duration and is highly heterogeneous, clinically and pathologically. Although there are an increasing number of studies on the association between genetic and environmental factors in the development of SZ, the actual distribution of the population with different levels of influence of these factors has not yet been fully elucidated. In this study, we focused on stress as an environmental factor and stratified SZ based on the expression levels of stress-responsive molecules in the postmortem prefrontal cortex.

Methods

We selected the following stress-responsive molecules: interleukin (IL) -1β, IL-6, IL-10, tumor necrosis factor-α, interferon-γ, glucocorticoid receptor, brain-derived neurotrophic factor, synaptophysin, S100 calcium-binding protein B, superoxide dismutase, postsynaptic density protein 95, synuclein, apolipoprotein A1 (ApoA1), ApoA2, and solute carrier family 6 member 4. We performed RNA sequencing in the prefrontal gray matter of 25 SZ cases and 21 healthy controls and conducted a hierarchical cluster analysis of SZ based on the gene expression levels of stress-responsive molecules, which yielded two clusters. After assessing the validity of the clusters, they were designated as the high stress-response SZ group and the low stress-response SZ group, respectively. Ingenuity Pathway Analysis of differentially expressed genes (DEGs) between clusters was performed, and Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining was conducted on four cases each in the high and low stress-response SZ groups to validate DNA damage.

Results

We found higher prevalence of family history of SZ in the low stress-response SZ group (0/3 vs. 5/4, p = 0.04). Pathway analysis of DEGs between clusters showed the highest enrichment for DNA double-strand break repair. TUNEL staining showed a trend toward a lower percentage of TUNEL-positive cells in the high stress-response SZ group.

Conclusion

Our results suggest that there are subgroups of SZ with different degrees of stress impact. Furthermore, the pathophysiology of these subgroups may be associated with DNA damage repair. These results provide new insights into the interactions and heterogeneity between genetic and environmental factors.

Childhood family environment predicting psychotic disorders over a 37-year follow-up - A general population cohort study

BACKGROUND

Childhood adverse effects and traumatic experiences increase the risk for several psychiatric disorders. We now investigated whether prospectively assessed childhood family environment per se contributes to increased risk for psychotic disorders in adulthood, and whether these family patterns are also relevant in the development of affective disorders.

METHODS

We used the Young Finns Data (n = 3502). Childhood family environment was assessed in 1980/1983 with previously constructed risk scores: (1) disadvantageous emotional family atmosphere (parenting practices, parents' life satisfaction, parents' mental disorder, parents' alcohol intoxication), (2) adverse socioeconomic environment (overcrowded apartment, home income, parent's employment, occupational status, educational level), and (3) stress-prone life events (home movement, school change, parental divorce, death, or hospitalization, and child's hospitalization). Psychiatric diagnoses (ICD-10 classification) over the lifespan were collected up to 2017 from the national registry of hospital care. Non-affective psychotic disorder and affective disorder groups were formed.

RESULTS

Frequent stress-prone life events predicted higher likelihood of non-affective psychotic disorders (OR = 2.401, p = 0.001). Adverse socioeconomic environment or emotional family atmosphere did not predict psychotic disorders. Only disadvantageous emotional family atmosphere predicted modestly higher likelihood of affective disorders (OR = 1.583, p = 0.013).

CONCLUSIONS

Our results suggest that childhood family environment and atmosphere patterns as such contribute to the risk for developing adulthood mental disorders with relative disorder specificity. The results emphasize the importance of both individual and public health preventive initiatives, including family support interventions.

Exploring biomedical and traditional care pathways for people with psychosis in Karachi, Pakistan

Background

Psychosis is known to have an adverse impact on an individual's quality of life, social and occupational functioning. A lack of treatment options for psychotic disorders such as schizophrenia contributes to adverse outcomes for individuals. A significant proportion of people with psychosis consult both formal and traditional routes of care. This warrants a need to explore perceptions around treatment options provided by diverse care providers, as the identification of avenues for support can improve psychiatric, alternative treatment and social outcomes.

Methods

Focus groups discussions (FGDs) and in-depth interviews (IDIs) were used. Interactive Research and Development (IRD) research staff conducted 20 IDIs and 2 FGDs to obtain information about the perspectives, treatment pathways and experiences of individuals with psychosis, their caregivers, and service providers. Questions for clinician care providers and faith healers revolved around perceptions of psychosis, service users' background, subject knowledge and treatment, feedback and referral mechanisms, and promotion of services. A thematic analysis was used to analyze the interviews and coding was conducted on NVivo.

Results

The results were categorized into five themes: perception of psychosis, experience of seeking/receiving care, assessment and diagnosis methods, promotion of services, and living with psychosis. Across service providers and patients, there was a wide variety of causes attributed to psychosis, and an overall lack of awareness regarding severe mental health conditions from both formal and informal care-providers. Biomedical treatment received mixed reviews, while some reported it as beneficial, the limited number of institutes and clinicians to cater for patients, stigma within society and care providers, the burden of caregiving, and misinformation from faith healers were all significant barriers to treatment.

Conclusion

The results highlight the use of traditional healing practices for psychosis in Pakistan, which, coupled with inadequate referral mechanisms, present an opportunity to bridge the treatment gap between clinical and traditional healing practices through integration of treatment within community structures and systems. Better awareness of psychosis and its treatment methods, alongside interventions that reduce stigma could help facilitate help-seeking behavior and reduce the burden of caregiving.

Spurious Autobiographical Memory of Psychosis: A Mechanistic Hypothesis for the Resolution, Persistence, and Recurrence of Positive Symptoms in Psychotic Disorders

Psychotic disorders are complex disorders with multiple etiologies. While increased dopamine synthesis capacity has been proposed to underlie psychotic episodes, dopamine-independent processes are also involved (less responsive to dopamine receptor-blocking medications). The underlying mechanism(s) of the reduction in antipsychotic responsiveness over time, especially after repeated relapses, remain unclear. Despite the consistent evidence of dopamine overactivity and hippocampal volume loss in schizophrenia, few accounts have been provided based on the interactive effect of dopamine on hippocampal synapse plasticity mediating autobiographical memory processes. The present hypothesis builds upon previous works showing the potential effects of dopamine overactivity on hippocampal-mediated neuroplasticity underlying autobiographical memory, alongside known patterns of autobiographical memory dysfunction in psychosis. We propose that spurious autobiographical memory of psychosis (SAMP) produced during active psychosis may be a key mechanism mediating relapses and treatment non-responsiveness. In a hyperdopaminergic state, SAMP is expected to be generated at an increased rate during active psychosis. Similar to other memories, it will undergo assimilation, accommodation, and extinction processes. However, if SAMP fails to integrate with existing memory, a discontinuity in autobiographical memory may result. Inadequate exposure to normalizing experiences and hyposalience due to overmedication or negative symptoms may also impede the resolution of SAMP. Residual SAMP is hypothesized to increase the propensity for relapse and treatment non-responsiveness. Based on recent findings on the role of dopamine in facilitating hippocampal synapse plasticity and autobiographical memory formation, the SAMP hypothesis is consistent with clinical observations of DUP effects, including the repetition of contents in psychotic relapses as well as the emergence of treatment non-responsiveness after repeated relapses. Clinical implications of the hypothesis highlight the importance of minimizing active psychosis, integrating psychosis memory, avoiding over-medication, and fostering normalizing experiences.

The moderating role of hair cortisol in the association of early and recent stress with stress-related phenotypes

Background

Increased hair cortisol concentrations (HCC) have been found in clinical samples of schizophrenia, first episode psychosis and clinical risk for psychosis, but evidence of such is scarce in schizotypy. High HCC are supposed to reflect elevated chronic stress. However, HCC were not directly associated with adversity measures and stress-related phenotypes in previous research. This study tested whether HCC moderated the association between a comprehensive range of psychosocial stressors with several stress-related phenotypes in a sample of nonclinical young adults. It was expected that stressors, either distal (i.e., early-life) or recent, would be associated with subclinical features, particularly for those with elevated HCC, reflecting the effects of a potential biological sensitization to stress.

Methods

The sample comprised 132 nonclinical young adults belonging to the Barcelona Longitudinal Investigation of Schizotypy Study (BLISS). Participants completed a questionnaire of childhood adversity and two complementary measures of recent life events, tapping threatening vs. more general life events. Both the frequency and subjective impact (positive vs. negative) of general life events were also assessed. Psychotic (i.e., schizotypy, suspiciousness) and non-psychotic (i.e., depression, anxiety) subclinical features as well as appraisals of perceived stress were examined. Hierarchical linear regressions and simple slope analyses were computed.

Results

HCC moderated the effects of both early and recent stress on suspiciousness as well as the effects of recent life events on perceived stress, such that those with higher HCC presented increased suspiciousness and perceived stress at higher levels of stress exposure. Positive, but not negative, recent life events were associated with decreased perceived stress and depression, and these associations were moderated by low HCC, indicating a buffering effect for those with a non-impaired HPA axis.

Conclusion

In line with the neural diathesis-stress model, results highlight the role of the interplay between the HPA axis and exposure to stressful experiences in exacerbating psychosis features and extend evidence to the nonclinical expression of the psychosis continuum. In addition, findings support the protective effect of positive experiences in decreasing stress appraisals and affective disturbances, which is consistent with emerging research about the relevance of positive factors in reducing the likelihood of psychopathological outcomes.

Psychosocial stress, interpersonal sensitivity, and social withdrawal in clinical high risk for psychosis: a systematic review

Stress has repeatedly been implicated in the onset and exacerbation of positive symptoms of psychosis. Increasing interest is growing for the role of psychosocial stress in the development of psychosis symptoms in individuals at Clinical High Risk (CHR) for psychosis. A systematic review was therefore conducted to summarize the existing evidence base regarding psychosocial stress, interpersonal sensitivity, and social withdrawal in individuals at CHR for psychosis. An electronic search of Ovid (PsychINFO, EMBASE, MEDLINE, and GLOBAL HEALTH) was conducted until February 2022. Studies that examined psychosocial stress in CHR were included. Twenty-nine studies were eligible for inclusion. Psychosocial stress, interpersonal sensitivity, and social withdrawal were higher in CHR individuals compared to healthy controls and there was some evidence of their association with positive symptoms of psychosis. Two types of psychosocial stressors were found to occur more frequently with CHR status, namely daily stressors, and early and recent trauma, while significant life events did not appear to be significant. Greater exposure to psychosocial stress, emotional abuse, and perceived discrimination significantly increased risk of transition to psychosis in CHR. No studies examined the role of interpersonal sensitivity on transition to psychosis in CHR. This systematic review provides evidence for the association of trauma, daily stressors, social withdrawal, and interpersonal sensitivity with CHR status. Further studies investigating the impact of psychosocial stress on psychosis symptom expression in individuals at CHR and its effects on transition to psychosis are therefore warranted.

Temperament & Character account for brain functional connectivity at rest: A diathesis-stress model of functional dysregulation in psychosis

The human brain's resting-state functional connectivity (rsFC) provides stable trait-like measures of differences in the perceptual, cognitive, emotional, and social functioning of individuals. The rsFC of the prefrontal cortex is hypothesized to mediate a person's rational self-government, as is also measured by personality, so we tested whether its connectivity networks account for vulnerability to psychosis and related personality configurations. Young adults were recruited as outpatients or controls from the same communities around psychiatric clinics. Healthy controls (n = 30) and clinically stable outpatients with bipolar disorder (n = 35) or schizophrenia (n = 27) were diagnosed by structured interviews, and then were assessed with standardized protocols of the Human Connectome Project. Data-driven clustering identified five groups of patients with distinct patterns of rsFC regardless of diagnosis. These groups were distinguished by rsFC networks that regulate specific biopsychosocial aspects of psychosis: sensory hypersensitivity, negative emotional balance, impaired attentional control, avolition, and social mistrust. The rsFc group differences were validated by independent measures of white matter microstructure, personality, and clinical features not used to identify the subjects. We confirmed that each connectivity group was organized by differential collaborative interactions among six prefrontal and eight other automatically-coactivated networks. The temperament and character traits of the members of these groups strongly accounted for the differences in rsFC between groups, indicating that configurations of rsFC are internal representations of personality organization. These representations involve weakly self-regulated emotional drives of fear, irrational desire, and mistrust, which predispose to psychopathology. However, stable outpatients with different diagnoses (bipolar or schizophrenic psychoses) were highly similar in rsFC and personality. This supports a diathesis-stress model in which different complex adaptive systems regulate predisposition (which is similar in stable outpatients despite diagnosis) and stress-induced clinical dysfunction (which differs by diagnosis).

Update on current animal models for schizophrenia: are they still useful?

PURPOSE OF REVIEW

Schizophrenia is a psychiatric disorder that has a significant socioeconomic impact worldwide. Antipsychotic drugs targeting dopamine transmission alleviate psychotic symptoms but with limited efficacy and tolerability. Animal models have long proven useful for drug discovery. The continued need for new treatment highlights the importance of animal models to study schizophrenia. The lack of new therapeutic compounds combined with the shortcomings of clinical design studies potentially decreased the enthusiasm for animal model use.

RECENT FINDINGS

In the current review, we discuss the central role of animal models for schizophrenia in providing new insights into neurobiological features and therapeutic development. The US National Institute of Mental Health released the Research Domain Criteria to guide preclinical model studies. Here, we point out the advances of this approach and debate its potential limitations when using animal models to study schizophrenia from the drug discovery perspective.

SUMMARY

Cross-validated animal models for schizophrenia are crucial to comprehend the cause, pathophysiology, and behavioral and biological features of the disease, to advance prevention and treatment, and the need to carefully evaluate and select appropriate paradigms when investigating novel therapeutic targets.

Increased parietal and occipital lobe gyrification predicts conversion to syndromal psychosis in a clinical high-risk cohort

BACKGROUND

Local gyrification index (lGI), indicative of the degree of cortical folding is a proxy marker for early cortical neurodevelopmental abnormalities. We studied the difference in lGI between those who do and do not convert to psychosis (non-converters) in a clinical high-risk (CHR) cohort, and whether lGI predicts conversion to psychosis.

METHODS

Seventy-two CHR participants with attenuated positive symptom syndrome were followed up for two years. The difference in baseline whole-brain lGI was examined on the T1-weighted MRIs between, i)CHR (N = 72) and healthy controls (N = 19), ii)Converters to psychosis (N = 24) and non-converters (N = 48), adjusting for age and sex, on Freesurfer-6.0. The significant cluster obtained in the converters versus non-converters comparison was registered as a region of interest to individual images of all 72 participants and lGI values were extracted from this region. A cox proportional hazards model was applied with these values to study whether lGI predicts conversion to psychosis.

RESULTS

lGI was not different between CHR and healthy controls. lGI was increased in converters in the right-sided inferior parietal and lateral occipital areas (corrected cluster-wise-p-value = 0.009, cohen's f = 0.42) compared to non-converters, which significantly increased the risk of onset of psychosis (p = 0.029, hazard ratio = 1.471).

CONCLUSIONS

Increased gyrification in the right-sided inferior parietal and lateral occipital area differentiates converters to psychosis in CHR, significantly increasing the risk of conversion to psychosis. This measure may reflect underlying traits in parts of the brain that develop earliest in-utero (parietal and occipital), conferring a heightened vulnerability to convert to syndromal psychosis subsequently.

Associations among psychosis, mood, anxiety, and posttraumatic stress symptoms: A network analysis

The associations among psychotic experiences (i.e., hallucinations and delusions), trauma exposure, and posttraumatic stress symptoms are complex and multidirectional. Using network analysis to understand how psychotic experiences and symptoms of posttraumatic stress disorder (PTSD) relate to one another may identify new interventional targets to treat comorbidity and its underlying pathological processes. This study aimed to use network analysis to examine the associations among psychotic experiences; negative symptoms of psychosis; and symptoms of PTSD, anxiety, and depression. In this population-based cohort study, 4,472 participants (36.7% male) were assessed for psychotic experiences, negative symptoms of psychosis, PTSD, anxiety, and depression at age 23 (M = 23.86 years, SD = 0.520) or 24 years (M = 24.03, SD = 0.848). Associations among symptoms were assessed via network analysis. Exploratory graph analysis identified three clusters of densely connected symptoms within the overall network: psychotic experiences; PTSD symptoms; and depressive and anxiety symptoms and negative symptoms of psychosis. Psychotic experiences had the strongest associations with other symptoms in the network, and symptoms of anxiety played a key role in bridging psychotic experiences, symptoms of PTSD, and depressive symptoms. Consistent with the stress reactivity and affective models for psychotic experiences, the results suggest that symptoms of anxiety and emotional distress (e.g., hyperarousal, panic) may have a key role in the development and maintenance of psychotic experiences and symptoms of PTSD. Targeting these symptoms may ameliorate symptom burden transdiagnostically.

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.

Depression Mediates the Relationships between Hallucinations, Delusions, and Social Isolation in First-Episode Psychosis

Social isolation is common among individuals with schizophrenia spectrum and other psychotic disorders. Research indicates that social isolation relates to poorer mental health outcomes, depression, and negative symptoms, with less known about its relationship with positive symptoms. This study examined depression as a mediator in the relationships between positive symptoms (i.e., hallucinations and delusions) and social isolation among an early treatment phase sample in the United States. Data were obtained from the Recovery After an Initial Schizophrenia Episode project of the National Institute of Mental Health's Early Treatment Program. Participants (N = 404) included adults between ages 15 and 40 in a first episode of psychosis. Data were analyzed using structural equation modeling in Mplus (Version 8). The study showed that delusions (b = .095, SE = 0.04, p < .05) and hallucinations (b = .076, SE = 0.03, p < .01) were directly related to depression, and that both delusions (b = .129, SE = 0.06, p < .05) and depression (b = .254, SE = 0.09, p < .05) were directly related to social isolation. Findings of this study determined that depression functioned as a mediator in the relationships between positive symptoms and social isolation. Targeting psychosis symptomatology and depression in treatment, improving social skills and social support networks, and considering the role of stigma in social isolation are of great importance in the prevention of poorer mental health outcomes.

The impact of childhood trauma and daily life experiences on emotional and psychotic symptom intensity in psychosis: An experience sampling study

Adverse childhood experiences create vulnerability to psychosis through biological and cognitive changes, and that may be observed as an increased emotional and psychotic response to daily life experiences in adulthood. This study aims to examine the effects of childhood maltreatment on psychotic patients' daily stress and emotional and psychotic intensity related to various experiences throughout the day. Daily activities and events, and emotional and psychotic intensity of forty-one psychotic patients were assessed with the Experience Sampling Method. The Childhood Trauma Questionnaire (CTQ) was used to evaluate childhood adversities. Multilevel regression analyses showed that all trauma subtypes, except for sexual abuse, were associated with increased psychosis and event-stress. Emotional maltreatment was the most associated trauma type with high negative and low positive affect and increased daily stress. Patients reported the highest stress and negative affect related to internal experiences but the lowest stress related to recreational actions. Social activities were also associated with higher positive affect and lower stress and psychosis, with the high CTQ group having greater stress in those activities. Our study demonstrates the negative impact of childhood trauma, especially emotional maltreatment, on daily stress and emotional and psychotic intensity in psychotic patients via different daily experiences.

Loneliness and psychosocial predictors of psychosis-proneness during COVID-19: Preliminary findings from Croatia

The present study investigated psychosocial predictors of psychosis-risk, depression, anxiety, and stress in Croatia during the COVID-19 pandemic. Given Croatia's recent transgenerational war trauma and the relative lack of available prodromal data, this study presents a unique opportunity to examine the impact of loneliness and other psychosocial factors on psychosis-risk and mental health in this population. 404 Croatian participants completed an anonymous online survey of physical and mental health questions. 48 participants met the criteria for elevated psychosis-risk on prodromal questionnaire (PQ-16). Loneliness had a significant impact on psychosis-risk. Exposure to trauma was associated with psychosis-risk and loneliness, while domestic abuse/violence was associated only with the distress surrounding psychotic-like symptoms. COVID concern was also associated with psychosis-risk. Lastly, the associations between psychosis-risk and depression, anxiety, and stress were robust. These findings highlight the important role of loneliness in psychosis-proneness in Croatia. Depression, anxiety, and stress were also closely related to elevated psychosis-risk. Loneliness is a highly salient issue for individuals with psychosis and it is important to target loneliness within a multi-faceted psychosocial intervention for those at risk for schizophrenia.

Schizophrenia: the new etiological synthesis

Schizophrenia has been an evolutionary paradox: it has high heritability, but it is associated with decreased reproductive success. The causal genetic variants underlying schizophrenia are thought to be under weak negative selection. To unravel this paradox, many evolutionary explanations have been suggested for schizophrenia. We critically discuss the constellation of evolutionary hypotheses for schizophrenia, highlighting the lack of empirical support for most existing evolutionary hypotheses-with the exception of the relatively well supported evolutionary mismatch hypothesis. It posits that evolutionarily novel features of contemporary environments, such as chronic stress, low-grade systemic inflammation, and gut dysbiosis, increase susceptibility to schizophrenia. Environmental factors such as microbial infections (e.g., Toxoplasma gondii) can better predict the onset of schizophrenia than polygenic risk scores. However, researchers have not been able to explain why only a small minority of infected people develop schizophrenia. The new etiological synthesis of schizophrenia indicates that an interaction between host genotype, microbe infection, and chronic stress causes schizophrenia, with neuroinflammation and gut dysbiosis mediating this etiological pathway. Instead of just alleviating symptoms with drugs, the parasite x genotype x stress model emphasizes that schizophrenia treatment should focus on detecting and treating possible underlying microbial infection(s), neuroinflammation, gut dysbiosis, and chronic stress.

Childhood adversity and psychotic disorders: Epidemiological evidence, theoretical models and clinical considerations

While genetic factors play a critical role in the risk for schizophrenia and other psychotic disorders, increasing evidence points to the role of childhood adversity as one of several environmental factors that can significantly impact the development, manifestations and outcome of these disorders. This paper reviews the epidemiological evidence linking childhood adversity and psychotic disorders and explores various theoretical models that seek to explain the connection. We discuss neurobiological parallels between the impact of childhood trauma and psychosis on the brain and then explore the impact of childhood adversity on different domains of clinical presentation. Finally, implications for prevention and treatment are considered, both on individual and structural levels.

Psychotic Symptoms After SARS-CoV-2 Infection

ABSTRACT

This case series reports three middle-aged male patients with no prior history of psychiatric disorders who developed psychotic symptoms with manic characteristics after COVID-19 infection. They presented mystic and paranoid delusions associated with euphoria, logorrheic, insomnia, and bizarre behaviors. Two of them required psychiatric hospitalization and one received corticosteroids. Treatment with antipsychotic medication improved their symptoms in a few weeks. This case series reports the new-onset psychosis probably due to COVID-19 infection. Pathogenetic speculation about the probable causes of COVID-19 psychosis, such as inflammatory reaction and corticosteroid use, was done. Moreover, other probable causes of manic psychosis, such as late-onset bipolar disorder, were also considered and ruled out. There is a need for more research to determine the causality between psychotic symptoms and COVID-19 infection.

A systematic review and meta-analysis of the association between emotional stress reactivity and psychosis

AIM

Emotional stress reactivity may be a mediating factor in the association between trauma and psychosis. This review aimed to (i) identify, summarise and critically evaluate the link between emotional stress reactivity and psychotic experiences (ii) examine evidence for a 'dose-response' relationship between stress reactivity and psychosis in the wider psychosis phenotype (i.e., sub-clinical symptoms).

METHODS

Electronic database searches (PsychINFO, MEDLINE, EMBASE) were conducted for studies which investigated the link between stress reactivity and psychosis, psychotic symptoms, or a vulnerability to developing psychosis (wider phenotype). Cross-sectional, experimental and experience sampling method study designs were eligible for inclusion.

RESULTS

Fourty five eligible articles were identified (N participants = 8830). Narrative synthesis showed that increased emotional stress reactivity was associated with psychosis and subclinical psychotic experiences across all study designs, however, findings were inconsistent across studies. The preliminary meta-analysis (k = 4, n = 383) showed increases in emotional stress reactivity was associated with higher negative affect in response to event-related stress, in those with psychosis compared to controls (mean difference in beta coefficients = 0.05, 95% CI 0.02-0.08, p = .004). However, this difference was small with a considerable degree of heterogeneity (p = .001, I²  = 81%) so results should be interpreted with caution.

CONCLUSIONS

Overall, the evidence suggests that there is a link between emotional stress reactivity and psychosis in those with psychosis, those at high risk of developing psychosis and in relation to subclinical psychotic-like experiences in the general population.

Hippocampal circuit dysfunction in psychosis

Despite strong evidence of the neurodevelopmental origins of psychosis, current pharmacological treatment is not usually initiated until after a clinical diagnosis is made, and is focussed on antagonising striatal dopamine receptors. These drugs are only partially effective, have serious side effects, fail to alleviate the negative and cognitive symptoms of the disorder, and are not useful as a preventive treatment. In recent years, attention has turned to upstream brain regions that regulate striatal dopamine function, such as the hippocampus. This review draws together these recent data to discuss why the hippocampus may be especially vulnerable in the pathophysiology of psychosis. First, we describe the neurodevelopmental trajectory of the hippocampus and its susceptibility to dysfunction, exploring this region's proneness to structural and functional imbalances, metabolic pressures, and oxidative stress. We then examine mechanisms of hippocampal dysfunction in psychosis and in individuals at high-risk for psychosis and discuss how and when hippocampal abnormalities may be targeted in these groups. We conclude with future directions for prospective studies to unlock the discovery of novel therapeutic strategies targeting hippocampal circuit imbalances to prevent or delay the onset of psychosis.

Using animal models for the studies of schizophrenia and depression: The value of translational models for treatment and prevention

Animal models of psychiatric disorders have been highly effective in advancing the field, identifying circuits related to pathophysiology, and identifying novel therapeutic targets. In this review, we show how animal models, particularly those based on development, have provided essential information regarding circuits involved in disorders, disease progression, and novel targets for intervention and potentially prevention. Nonetheless, in recent years there has been a pushback, largely driven by the US National Institute of Mental Health (NIMH), to shift away from animal models and instead focus on circuits in normal subjects. This has been driven primarily from a lack of discovery of new effective therapeutic targets, and the failure of targets based on preclinical research to show efficacy. We discuss why animal models of complex disorders, when strongly cross-validated by clinical research, are essential to understand disease etiology as well as pathophysiology, and direct new drug discovery. Issues related to shortcomings in clinical trial design that confound translation from animal models as well as the failure to take patient pharmacological history into account are proposed to be a source of the failure of what are likely effective compounds from showing promise in clinical trials.

Impact of childhood trauma on antipsychotic effectiveness in schizophrenia spectrum disorders: A prospective, pragmatic, semi-randomized trial

Antipsychotic medications are generally effective in ameliorating psychotic symptoms in schizophrenia spectrum disorders (SSDs). Identifying predictors associated with poor treatment response is important for a personalized treatment approach. Childhood trauma (CT) may have a general and differential effect on the effectiveness of different types of antipsychotics in SSDs. The Bergen-Stavanger-Trondheim-Innsbruck (BeSt InTro) study is a pragmatic, researcher-initiated, semi-randomized trial. The present study aimed to investigate symptom change (the Positive and Negative Syndrome Scale) from baseline to 1, 3, 6, 12, 26, 39 and 52 weeks of antipsychotic treatment (amisulpride, aripiprazole and olanzapine) by group (CT/no CT). Participants (n = 98) with diagnoses within the schizophrenia spectrum (F20-29 in the International Classification of Diseases - 10th Revision) were randomized to receive amisulpride, aripiprazole or olanzapine, and for this study categorized into groups of none and low CT, and moderate to severe CT according to thresholds defined by the Childhood Trauma Questionnaire Short-Form manual. CT in SSDs predicted an overall slower treatment response and less antipsychotic effectiveness after 26 weeks of treatment, which was statistically nonsignificant at 52 weeks. Secondary analyses showed a differential effect of CT related to type of antipsychotic medication: patients with SSDs and CT who received olanzapine showed less antipsychotic effectiveness throughout 52 weeks of treatment. The intention-to-treat and per-protocol analyses were convergent. Our findings indicate that in patients with SSD and CT, delayed response to antipsychotics could be expected, and a longer evaluation period before considering change of medication may be recommended.

Association between genetic and socioenvironmental risk for schizophrenia during upbringing in a UK longitudinal cohort

BACKGROUND

Associations of socioenvironmental features like urbanicity and neighborhood deprivation with psychosis are well-established. An enduring question, however, is whether these associations are causal. Genetic confounding could occur due to downward mobility of individuals at high genetic risk for psychiatric problems into disadvantaged environments.

METHODS

We examined correlations of five indices of genetic risk [polygenic risk scores (PRS) for schizophrenia and depression, maternal psychotic symptoms, family psychiatric history, and zygosity-based latent genetic risk] with multiple area-, neighborhood-, and family-level risks during upbringing. Data were from the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally-representative cohort of 2232 British twins born in 1994-1995 and followed to age 18 (93% retention). Socioenvironmental risks included urbanicity, air pollution, neighborhood deprivation, neighborhood crime, neighborhood disorder, social cohesion, residential mobility, family poverty, and a cumulative environmental risk scale. At age 18, participants were privately interviewed about psychotic experiences.

RESULTS

Higher genetic risk on all indices was associated with riskier environments during upbringing. For example, participants with higher schizophrenia PRS (OR = 1.19, 95% CI = 1.06-1.33), depression PRS (OR = 1.20, 95% CI = 1.08-1.34), family history (OR = 1.25, 95% CI = 1.11-1.40), and latent genetic risk (OR = 1.21, 95% CI = 1.07-1.38) had accumulated more socioenvironmental risks for schizophrenia by age 18. However, associations between socioenvironmental risks and psychotic experiences mostly remained significant after covariate adjustment for genetic risk.

CONCLUSION

Genetic risk is correlated with socioenvironmental risk for schizophrenia during upbringing, but the associations between socioenvironmental risk and adolescent psychotic experiences appear, at present, to exist above and beyond this gene-environment correlation.

Psychosocial Stress, Epileptic-Like Symptoms and Psychotic Experiences

Background

Current research suggests that stressful life experiences and situations create a substantive effect in the development of the initial manifestations of psychotic disorders and may influence temporo-limbic epileptic-like activity manifesting as cognitive and affective seizure-like symptoms in non-epileptic conditions.

Methods

The current study assessed trauma history, hair cortisol levels, epileptic-like manifestations and other psychopathological symptoms in 56 drug naive adult young women experiencing their initial occurrence of psychosis.

Results

Hair cortisol levels among patients experiencing their initial episode of psychosis, were significantly correlated with stress symptoms measured by Trauma Symptom Checklist-40 (r = − 0.48, p < 0.01), and complex partial seizure-like symptoms measured by the Complex Partial Seizure-Like Symptoms Inventory (r = − 0.33, p < 0.05) and LSCL-33 (r = − 0.33, p < 0.05). Hair cortisol levels were not found to be significantly correlated with symptoms of anxiety and depression measured by Beck depression Inventory and Zung Anxiety Scale.

Conclusion

These findings suggest a significant relationship between epileptic-like symptoms and stress responses demonstrated by patients in their first psychotic episode. These findings may suggest the potential for research to explore usefulness of anticonvulsant treatment in patients who do not respond to usual psychotropic medication.

The Clinical Characteristics of Patients With Borderline Personality Disorder in Different Treatment Settings

The present report from the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) Project compares patients with borderline personality disorder (BPD) in an outpatient practice (n = 390) and a partial hospital setting (n = 358) on diagnostic comorbidities, symptoms experienced, suicidality, and occupational impairment. The patients in the partial program were diagnosed with significantly more psychiatric disorders and were more frequently diagnosed with dysthymia, generalized anxiety disorder, alcohol and substance use disorders, adjustment disorders, and posttraumatic stress disorder. Those at the partial hospital had significantly higher levels of suicidal ideation than those in the outpatient practice. The samples did not differ on utilization of disability or suicide attempts. Treatment setting may have implications in the recognition of the disorder in clinical practice, the development and support of etiological theories, identification of core deficits, and evaluation of psychosocial morbidity associated with BPD.

The Moderating Role of the FKBP5 Gene Polymorphisms in the Relationship between Attachment Style, Perceived Stress and Psychotic-like Experiences in Non-Clinical Young Adults

Numerous studies have reported that stressful life experiences increase the risk of psychosis and psychotic-like experiences (PLEs). Common variations of the FKBP5 gene have been reported to impact the risk of psychosis by moderating the effects of environmental exposures. Moreover, anxious and avoidant attachment styles have been shown to increase both the level of perceived stress and the risk for psychosis development. In the present cross-sectional study, we aimed to investigate whether variants of the FKBP5 gene moderate the effects of attachment styles and the level of perceived stress on the development of PLEs. A total of 535 non-clinical undergraduates were genotyped for six FKBP5 single nucleotide polymorphisms (SNPs) (rs3800373, rs9470080, rs4713902, rs737054, rs1360780 and rs9296158). The Psychosis Attachment Measure (PAM), the Perceived Stress Scale-10 (PSS-10) and the Prodromal Questionnaire 16 (PQ-16) were administered to assess attachment styles, the level of perceived stress and PLEs, respectively. Anxious attachment style, lower levels of perceived self-efficacy and higher levels of perceived helplessness were associated with a significantly higher number of PLEs. The main effects of attachment style on the severity of PLEs were significant in models testing for the associations with perceived self-efficacy and three FKBP5 SNPs (rs1360780, rs9296158 and rs9470080). The main effect of rs38003733 on the number of PLEs was observed, with GG homozygotes reporting a significantly higher number of PLEs in comparison to T allele carriers. In individuals with dominant anxious attachment style, there was a significant effect of the interaction between the FKBP5 rs4713902 SNP and self-efficacy on the severity of PLEs. Among rs4713902 TT homozygotes, a low level of perceived self-efficacy was associated with higher severity of PLEs. In subjects with non-dominant anxious attachment, a low level of perceived self-efficacy was associated with a higher number of PLEs, regardless of the genotype. Our results indicate that the FKBP5 gene might moderate the relationship between attachment, perceived stress and PLEs.

Study on the Correlation Between Iris Characteristics and Schizophrenia

BACKGROUND

Recently, researchers have conducted many studies on the potential contribution of the retina and other eye structures on schizophrenia. This study aimed to evaluate differences in iris characteristics between patients with schizophrenia and healthy individuals so as to find more easily accessible and easily measurable biomarkers with a view to improving clinical assessments and furthering our understanding of the disease.

METHODS

Overall, 80 patients with schizophrenia and 52 healthy individuals were included in the case group and the control group, respectively. Iris images were collected from all subjects to compare differences in the structure and color of the iris. The Positive and Negative Symptom Scale (PANSS) and the Modified Overt Aggression Scale (MOAS) were used to evaluate the clinical symptoms and characteristics of 45 first-episode untreated schizophrenics, and analyzed correlations between iris characteristics and schizophrenia symptoms.

RESULTS

There were significant differences in iris crypts (P<0.05) and pigment spots (P<0.01) between the case and control group, but no significant difference was found in iris wrinkles (P<0.05). The logistic regression analysis demonstrated that the total iris crypts [odds ratio (OR) 1.166, 95% confidence interval (CI) 1.022-1.330] and total iris pigment spots (OR 1.815, 95% CI 1.186-2.775) increased the risk of suffering from schizophrenia. Furthermore, it was demonstrated that the number of iris crypts was positively associated with the MOAS score (r=0.474, P<0.01). Moreover, the number of the iris pigment spots (r=0.395, P<0.01) and wrinkles (r=0.309, P<0.05) were positively correlated with the subjects' negative symptom scores, respectively.

CONCLUSION

Iris crypts and pigment spots were identified as potential biomarkers for detecting schizophrenia. In patients with first-episode untreated schizophrenia, iris characteristics may help psychiatrists to identify the illness and its severity, and to detect characteristic clinical symptoms.

Consequences of pandemic-associated social restrictions: Role of social support and the oxytocin system

During pandemics, governments take drastic actions to prevent the spreading of the disease, as seen during the present COVID-19 crisis. Sanctions of lockdown, social distancing and quarantine urge people to exclusively work and teach at home and to restrict social contacts to a minimum; lonely people get into further isolation, while families` nerves are strained to the extreme. Overall, this results in a dramatic and chronic increase in the level of psychosocial stress over several months mainly caused by i) social isolation and ii) psychosocial stress associated with overcrowding, social tension in families, and domestic violence. Moreover, pandemic-associated social restrictions are accompanied by loss of an essential stress buffer and important parameter for general mental and physical health: social support. Chronic psychosocial stress and, in particular, social isolation and lack of social support affect not only mental health, but also the brain oxytocin system and the immune system. Hence, pandemic-associated social restrictions are expected to increase the risk of developing psychopathologies, such as depression, anxiety-related and posttraumatic stress disorders, on the one hand, but also to induce a general inflammatory state and to impair the course of infectious disorders on the other. Due to its pro-social and stress-buffering effects, resulting in an anti-inflammatory state in case of disease, the role of the neuropeptide oxytocin will be discussed and critically considered as an emerging treatment option in cases of pandemic-induced psychosocial stress, viral infection and during recovery. In this review, we aim to critically focus on possible short- and long-term consequences of social restrictions on mental health and the immune system, while discussion oxytocin as a possible treatment option.

Burnout among medical students of the University of Kerbala and its correlates

Background

Burnout is prevalent among medical students. Throughout their training, medical students face many psychosocial stresses that, if not managed, might cause burnout syndrome. Burnout could negatively impact students’ life and their academic performance. This study aims to estimate the prevalence of burnout among medical students at the College of Medicine, University of Kerbala, and assess factors associated with it.

An analytic cross-sectional study. A sample of 424 students from all academic years from the College of Medicine, University of Kerbala, was approached. Data collection was conducted from June 11 to July 3, 2020, through a self-administered online questionnaire based on the Maslach Burnout Inventory Student Survey (MBI-SS). The MBI-SS included 15 questions with a 7-point rating ranging from 0 (never) to 6 (always). The tool measures three subscales: emotional exhaustion (5 questions), Cynicism (4 questions), and professional efficacy (6 questions). Statistical Package for the Social Sciences (SPSS) program version 24 was used for data analysis. Binary logistic regression was used to assess the association between burnout and students̓ variables, P value of a level < 0.05 considered statistically significant.

Results

The prevalence of burnout syndrome among medical students was 38.2%. About 85.6% of students had high emotional exhaustion, 77.8% had high cynicism, and 32.5% exhibited low professional efficacy. Female gender, regular use of legal substances, and family history of mental diseases were associated with significantly high rates of burnout.

Conclusions

Burnout is prevalent among medical students of the University of Kerbala with quite high levels of emotional exhaustion and cynicism and lower professional efficacy levels. Faculties of medicine need to consider burnout among their students and works to reduce unnecessary stresses by modifying and upgrading the educational and clinical environments.

Gene-Environment Interactions in Schizophrenia: A Literature Review

Schizophrenia is a devastating mental illness with a strong genetic component that is the subject of extensive research. Despite the high heritability, it is well recognized that non-genetic factors such as certain infections, cannabis use, psychosocial stress, childhood adversity, urban environment, and immigrant status also play a role. Whenever genetic and non-genetic factors co-exist, interaction between the two is likely. This means that certain exposures would only be of consequence given a specific genetic makeup. Here, we provide a brief review of studies reporting evidence of such interactions, exploring genes and variants that moderate the effect of the environment to increase risk of developing psychosis. Discovering these interactions is crucial to our understanding of the pathogenesis of complex disorders. It can help in identifying individuals at high risk, in developing individualized treatments and prevention plans, and can influence clinical management.

Examining the Relationship Between Hair Cortisol With Stress-Related and Transdiagnostic Subclinical Measures

Background: Hair cortisol concentrations (HCC) provide a retrospective examination of long-term cortisol production as a measure of the hypothalamic-pituitary-adrenal (HPA) axis functioning, one of the major neural systems implicated in mediating the effects of stress on mental illness. However, evidence about the relationship between HCC with stressors and symptoms is scattered. In the present study, we aimed to examine the association between HCC and a wide range of stress-related and transdiagnostic subclinical measures in a sample of non-clinical young adults with a wide distribution of schizotypy. Methods: A total sample of 132 non-clinical young adults recruited at college and technical schools oversampled for schizotypy scores were assessed on distal and proximal stressful experiences, appraisals of stress, traits and symptoms of the affective, psychosis and dissociation spectrums, as well as stress-buffering measures, and provided 3 cm-hair samples. Results: No significant associations were found between HCC and any of the stress-related and subclinical measures. Only suspiciousness and disorganization showed a trend for a positive association with HCC but the magnitude was small. Conclusions: The present findings support previous studies indicating an overall lack of concordance between a broad range of stress-related and (sub)clinical phenotypic measures with hair cortisol. This study examined for the first time the relationship of HCC with the non-clinical expression of the psychosis spectrum, that is, schizotypy, which complements previous studies on clinical high risk and established psychosis and offers a promising strategy for studying possible HPA dysfunctions characterizing the subclinical psychosis continuum without the confounds associated to clinical psychosis.

Is Psychopathy a Mental Disorder or an Adaptation? Evidence From a Meta-Analysis of the Association Between Psychopathy and Handedness

Psychopathy has historically been conceptualized as a mental disorder, but there is growing evidence that it may instead be an alternative, adaptive life history strategy designed by natural selection. Although the etiology of mental disorders is not fully understood, one likely contributor is perturbations affecting neurodevelopment. Nonright-handedness is a sign of such perturbations, and therefore can be used to test these competing models. If psychopathy is a mental disorder, psychopaths should show elevated rates of nonright-handedness. However, an adaptive strategy perspective expects psychopaths to be neurologically healthy and therefore predicts typical rates of nonright-handedness. We meta-analyzed 16 studies that investigated the association between psychopathy and handedness in various populations. There was no difference in the rates of nonright-handedness between community participants high and low in psychopathy. Furthermore, there was no difference between psychopathic and nonpsychopathic offenders in rates of nonright-handedness, though there was a tendency for offenders scoring higher on the Interpersonal/Affective dimension of psychopathy to have lower rates of nonright-handedness, and for offenders scoring higher on the Behavioral dimension of psychopathy to have higher rates of nonright-handedness. Lastly, there was no difference in rates of nonright-handedness between psychopathic and nonpsychopathic mental health patients. Thus, our results fail to support the mental disorder model and partly support the adaptive strategy model. We discuss limitations of the meta-analysis and implications for theories of the origins of psychopathy.

Recent stressful life events and stress sensitivity in children and adolescents at clinical risk for psychosis

Although psychosocial stress is consistently described as a casual factor for psychosis, the role of recent stressful life events (SLEs) is inconclusive. Studies with subjects with psychosis risk syndrome (PRS), fail to show a large number of SLEs but suggest greater stress sensitivity in these populations. We evaluate the presence of recent SLEs and stress sensitivity, and their relationship with symptoms and functionality in a sample consisting exclusively of help-seeking children and adolescents. Seventy-two 10- to 17-year-old help-seeking subjects who met PRS criteria and forty-two healthy control (HC) subjects participated in a naturalistic multi-site study. Measures of stress included the Stressful Life Events Schedule (SLES) and the G4 item of the Scale for Prodromal Syndromes (SOPS) scale. Child and adolescent PRS subjects presented greater number of SLEs during the previous year, greater total accumulated stress, greater sensitivity to stress, and more impaired tolerance to normal stress than did HC subjects. Stress measures showed a relationship with positive and negative attenuated symptoms, clinical variables and functionality. Our results support the role of stress in the PRS status. It reinforces the suggested differences for clinical presentation of PRS in terms of age, highlighting the importance of gathering data on the under-18 population.

BDNF in antipsychotic naive first episode psychosis: Effects of risperidone and the immune-inflammatory response system

Brain-derived neurotrophic factor (BDNF) and the immune-inflammatory response system (IRS) have been implicated in the pathophysiology of schizophrenia. However, no research examined the associations between BDNF and immune activation both before and after treatment in antipsychotic-naïve first episode psychosis (AN-FEP). This study aims to examine serum BDNF levels and their association with IRS and the compensatory immune-regulatory reflex system (CIRS) in AN-FEP before and after risperidone treatment. We included 31 AN-FEP and 22 healthy controls. AN-FEP showed reduced levels of BDNF as compared to controls, and BDNF levels normalized after treatment with risperidone. BDNF levels were inversely correlated with a greater IRS response. Higher levels of IRS/CIRS biomarkers were associated with lower levels of BDNF including M1 macrophage, T-helper (Th)-1, Th-2, and Th-17, and T-regulatory (Treg) cell responses. Our findings indicate that AN-FEP is characterized by decreased levels of BDNF, which are normalized after treatment with risperidone. BDNF levels were inversely associated with activated immune-inflammatory pathways. The findings support the hypothesis that, increased IRS is linked to neurotoxicity, and that a decrease in BDNF may be part of the IRS/CIRS responses in FEP and, thus, be involved in the development of psychosis.

THC-induced behavioral stereotypy in zebrafish as a model of psychosis-like behavior

High doses of the Cannabis constituent Δ9-tetrahydrocannabinol (THC) increase the risk of psychosis in humans. Highly accessible animal models are needed to address underlying mechanisms. Using zebrafish with a conserved endocannabinoid system, this study investigates the acute effects of THC on adult zebrafish behavior and the mechanisms involved. A concentration-dependent THC-induced behavioral stereotypy akin to THC's effect in rats and the psychotropics phencyclidine and ketamine in zebrafish was established. Distinctive circular swimming during THC-exposure was measured using a novel analytical method that we developed, which detected an elevated Repetition Index (RI) compared to vehicle controls. This was reduced upon co-administration of N-methyl-D-aspartate (NMDA) receptor agonist NMDA, suggesting that THC exerts its effects via biochemical or neurobiological mechanisms associated with NMDA receptor antagonism. Co-treatment of γ-aminobutyric acid receptor antagonist pentylenetetrazol also showed signs of reducing the RI. Since THC-induced repetitive behavior remained in co-administrations with cannabinoid receptor 1 inverse agonist AM251, the phenotype may be cannabinoid receptor 1-independent. Conversely, the inverse cannabinoid receptor 2 agonist AM630 significantly reduced THC-induced behavioral stereotypy, indicating cannabinoid receptor 2 as a possible mediator. A significant reduction of the THC-RI was also observed by the antipsychotic sulpiride. Together, these findings highlight this model's potential for elucidating the mechanistic relationship between Cannabis and psychosis.

Induced pluripotent stem cells for 2D and 3D modelling the biological basis of schizophrenia and screening possible therapeutics

Induced pluripotent stem cells (iPSCs) are providing unprecedented insight into complex neuropsychiatric disorders such as schizophrenia (SZ). Here we review the use of iPSCs for investigating the etiopathology and treatment of SZ, beginning with conventional in vitro two-dimensional (2D; monolayer) cell modelling, through to more advanced 3D tissue studies. With the advent of 3D modelling, utilising advanced differentiation paradigms and additive manufacturing technologies, inclusive of patient-specific cerebral/neural organoids and bioprinted neural tissues, such live disease-relevant tissue systems better recapitulate "within-body" tissue function and pathobiology. We posit that by enabling better understanding of biological causality, these evolving strategies will yield novel therapeutic targets and accordingly, drug candidates.

Psychotic-like experiences in Chinese children and adolescents: The effect of earthquake exposure, maltreatment and negative life events

AIM

Psychotic-like experiences (PLEs) are common in adolescents who have experienced or are experiencing trauma. However, the potential relationships between exposure to a major earthquake, negative life events or maltreatment and PLEs in Chinese adolescents are poorly understood. Therefore, this study explored the prevalence of PLEs and the psychosocial correlates in adolescent earthquake survivors.

METHODS

A total of 6132 adolescents from 11 primary and high schools in the areas most severely affected by the Ya'an earthquake completed questionnaires on earthquake exposure, maltreatment, negative life events and PLEs, which included paranoid ideation and psychoticism.

RESULTS

It was found that earthquake exposure significantly contributed to the PLEs, child maltreatment explained a significant amount of the PLE variances, emotional abuse had the most important PLE role and negative life events also explained a large amount of the PLE variances, of which interpersonal difficulties and academic pressure had the greatest effects.

CONCLUSIONS

Interventions should seek to reduce parental emotional abuse, reduce academic performance pressure, improve interpersonal skills and resolve interpersonal difficulties, and specific interventions should target children and adolescents exposed to the earthquake to prevent PLEs, schizophrenia or other mental illnesses arising from multiple traumas.

The FKBP5 genotype and childhood trauma effects on FKBP5 DNA methylation in patients with psychosis, their unaffected siblings, and healthy controls

Hypothalamic-pituitary-adrenal (HPA) axis activity mediates the relationship between childhood trauma (CT) and psychosis. The FKBP5 gene, one of the key regulators of HPA axis activity after stress exposure, has been found associated with psychosis. Allele-specific and CT related FKBP5 demethylation in intron 7 was revealed in different psychiatric disorders. However, no studies have investigated FKBP5 methylation in subjects with different genetic liability for psychosis. A total of 144 participants were included in the study: 48 patients with psychotic disorders, 50 unaffected siblings, and 46 healthy controls. CT was assessed by Childhood Trauma Questionnaire. The FKBP5 rs1360780 was genotyped and FKBP5 methylation analyses were performed using bisulfite conversion followed by Sanger sequencing at three CpG sites in intron 7. Mixed linear model was used to assess group differences depending on rs1360780 T allele and CT. Results showed a significant T allele-dependent decrease of FKBP5 methylation in patients compared to unaffected siblings and controls. Effect of interaction between T allele and CT exposure on FKBP5 demethylation was found in controls. No effect of both risk factors (T allele and CT) on FKBP5 methylation level was found in unaffected siblings. We confirmed previous evidence of the association between the FKBP5 rs1360780 T allele, CT, and decreased FKBP5 methylation in intron 7. Allele-specific FKBP5 demethylation found in patients could shed a light on altered HPA axis activity in a subgroup of patients related to stress-induced psychosis. FKBP5 methylation and potential protective mechanisms in unaffected siblings after trauma exposure require further investigation.

The effect of effort-reward imbalance on brain structure and resting-state functional connectivity in individuals with high levels of schizotypal traits

INTRODUCTION

Effort-reward imbalance (ERI) is a typical psychosocial stress. Schizotypal traits are attenuated features of schizophrenia in the general population. According to the diathesis-stress model, schizotypal traits and psychosocial stress contribute to the onset of schizophrenia. However, few studies examined the effects of these factors on brain alterations. This study aimed to examine relationships between ERI, schizotypal traits and brain structures and functions.

METHODS

We recruited 37 (13 male, 24 female) participants with high levels of schizotypal traits and 36 (12 male, 24 female) participants with low levels of schizotypal traits by the Schizotypal Personality Questionnaire (SPQ). The Chinese school version of the effort-reward imbalance questionnaire (C-ERI-S) was used to measure ERI. We conducted the voxel-based morphometry (VBM) and whole brain resting-state functional connectivity (rsFC) analysis using reward or stress-related regions as seeds.

RESULTS

Participants with high levels of schizotypal traits were more likely to perceive ERI. The severity of ERI was correlated with grey matter volume (GMV) reduction of the left pallidum and altered rsFC among the prefrontal, striatum and cerebellum in participants with high levels of schizotypal traits.

CONCLUSION

ERI is associated with GMV reduction and altered rsFC in individuals with high levels of schizotypal traits.