Relationship between the domains of theory of mind, social dysfunction, and oxytocin in schizophrenia

The impact of childhood trauma exposure on social functioning in schizophrenia: the moderated mediation role of oxytocin and oxytocin receptor gene polymorphisms

BACKGROUND

Childhood trauma has been linked to increased risk of schizophrenia and social dysfunction, and oxytocin and its receptor gene have been implicated in regulating social behavior. This study investigated the potential role of oxytocin and oxytocin receptor gene (OXTR) in mediating the effects of childhood trauma on social functioning in schizophrenia.

METHODS

The study consisted of 382 patients with schizophrenia and 178 healthy controls who were assessed using the Taiwanese version of the Childhood Trauma Questionnaire (CTQ-SF), the Social Functioning Scale (SFS), and plasma oxytocin levels. DNA was extracted to genotype the OXTR and ten single-nucleotide polymorphisms (SNPs; rs2254298, rs237885, rs237887, rs237899, rs53576, rs9840864, rs13316193, rs7632287, rs1042778, and rs237895) were selected.

RESULTS

Patients with schizophrenia showed higher CTQ-SF scores (t = 12.549, p < 0.001), lower SFS scores (t = -46.951, p < 0.001), and lower plasma oxytocin levels (t = -5.448, p < 0.001) compared to healthy controls. The study also found significant differences in OXTR SNPs between both groups, with risk alleles being more prevalent in patients with schizophrenia (t = 2.734, p = 0.006). Results indicated a significant moderated mediation effect, with oxytocin and the OXTR SNPs partially mediating the relationship between childhood trauma exposure and social functioning in patients with schizophrenia (index of mediation = 0.038, 95% CI [0.033-0.044]).

CONCLUSIONS

The findings suggest that oxytocin and its receptor gene may be promising targets for interventions aimed at improving social functioning in patients with a history of childhood trauma and schizophrenia. However, further research is needed to fully understand these effects and the potential of oxytocin-based interventions in this population.

Linking childhood trauma to the psychopathology of schizophrenia: the role of oxytocin

Childhood trauma has been linked to schizophrenia, but underlying biological mechanisms remain elusive. This study explored the potential role of plasma oxytocin as a mediator in the relationship between childhood trauma and the psychopathology of schizophrenia. 160 patients with schizophrenia and 80 age- and sex-matched healthy controls were assessed for childhood trauma experiences using the Childhood Trauma Questionnaire and structured interviews. Psychopathology was evaluated using the Positive and Negative Syndrome Scale and plasma oxytocin levels were measured. Results showed that patients with schizophrenia had lower oxytocin levels and higher childhood trauma scores than healthy controls. There was a significant correlation between childhood trauma scores and psychopathology, with plasma oxytocin levels being inversely associated with psychopathology, except for positive symptoms. Hierarchical regression analysis indicated that both childhood trauma scores and plasma oxytocin levels significantly predicted psychopathology. Plasma oxytocin levels partially mediated the relationship between childhood trauma and schizophrenia psychopathology. This study underscores the potential role of oxytocin in bridging the gap between childhood trauma and schizophrenia.

Effects of mind-body therapies on schizophrenia: A systematic review and network meta-analysis

OBJECTIVE

The objective of this meta-analysis is to evaluate and compare the effectiveness of different mind-body therapies in reducing the symptoms of schizophrenia.

METHODS

A systematic search was performed using databases such as PubMed, Embase, Cochrane Library, Web of Science, and Scopus. Randomized controlled trials that assessed the effects of mind-body therapies on patients with schizophrenia were included. The search covered the period between the inception of each database and November 17th, 2022. The methodological quality of the trials was assessed using the Cochrane risk of bias tool. A network meta-analysis was conducted to compare the effects of various mind-body therapies, including Yoga, Mindfulness, Tai Chi, Baduanjin, and Yijinjing.

RESULTS

The analysis included 22 randomized controlled trials involving a total of 2064 subjects. The network meta-analysis revealed that Yoga and Mindfulness interventions were more effective than other mind-body therapies in reducing the symptoms of schizophrenia. Specifically, Yoga improved PANSS-positive symptom scores (SUCRA: 74.8 %) and PANSS-negative symptom scores (SUCRA: 80.4 %), whereas Mindfulness improved PANSS-positive symptom scores (SUCRA: 85.6 %).

CONCLUSION

The findings of this study indicate that Yoga may be a promising intervention for the treatment of schizophrenia. However, the small sample size and the low quality of the included studies have limited the generalizability of our findings Therefore, this study must be understood with caution, and further investigation is warranted when more relevant studies emerge.

The Interplay of Oxytocin and Attachment in Schizophrenic Patients: An fMRI Study

BACKGROUND

Attachment theory offers an important framework for understanding interpersonal interaction experiences. In the present study, we examined the neural correlates of attachment patterns and oxytocin in schizophrenic patients (SZP) compared to healthy controls (HC) using fMRI. We assumed that male SZP shows a higher proportion of insecure attachment and an altered level of oxytocin compared to HC. On a neural level, we hypothesized that SZP shows increased neural activation in memory and self-related brain regions during the activation of the attachment system compared to HC.

METHODS

We used an event-related design for the fMRI study based on stimuli that were derived from the Adult Attachment Projective Picture System to examine attachment representations and their neural and hormonal correlates in 20 male schizophrenic patients compared to 20 male healthy controls.

RESULTS

A higher proportion of insecure attachment in schizophrenic patients compared to HC could be confirmed. In line with our hypothesis, Oxytocin (OXT) levels in SZP were significantly lower than in HC. We found increasing brain activations in SZP when confronted with personal relevant sentences before attachment relevant pictures in the precuneus, TPJ, insula, and frontal areas compared to HC. Moreover, we found positive correlations between OXT and bilateral dlPFC, precuneus, and left ACC in SZP only.

CONCLUSION

Despite the small sample sizes, the patients' response might be considered as a mode of dysregulation when confronted with this kind of personalized attachment-related material. In the patient group, we found positive correlations between OXT and three brain areas (bilateral dlPFC, precuneus, left ACC) and may conclude that OXT might modulate within this neural network in SZP.

Mentalization, Oxytocin, and Cortisol in the General Population

Although evidence suggests the role of oxytocin and cortisol in social cognition and emotion regulation, it is less known how their peripheral levels are related to social perception (biological motion detection) and mentalization (self-reflection, emotional awareness, and affect regulation) in the general population. We assessed 150 healthy individuals from the general community on a mentalization questionnaire, a scale measuring the intensity of positive and negative emotions, and measured oxytocin and cortisol levels in the saliva. Oxytocin but not cortisol level and biological motion detection predicted mentalization abilities. There was a positive correlation between mentalization and positive emotions and between mentalization and biological motion detection. These results suggest that oxytocin, but not cortisol, plays a role in low-level perceptual and self-reflective aspects of social cognition.

Exploring a Possible Interplay between Schizophrenia, Oxytocin, and Estrogens: A Narrative Review

Schizophrenia is characterized by symptoms of psychosis and sociocognitive deficits. Considering oxytocin’s antipsychotic and prosocial properties, numerous clinical, and preclinical studies have explored the neuropeptide’s therapeutic efficacy. Sex differences in the clinical course of schizophrenia, as well as in oxytocin-mediated behaviors, indicate the involvement of gonadal steroid hormones. The current narrative review aimed to explore empirical evidence on the interplay between schizophrenia psychopathology and oxytocin’s therapeutic potential in consideration of female gonadal steroid interactions, with a focus on estrogens. The review was conducted using the PubMed and PsychINFO databases and conforms to the Scale for the Assessment of Narrative Review Articles (SANRA) guidelines. The results suggest a potential synergistic effect of the combined antipsychotic effect of oxytocin and neuroprotective effect of estrogen on schizophrenia. Consideration of typical menstrual cycle-related hormonal changes is warranted and further research is needed to confirm this assumption.