Given that human trust behavior is heritable and intranasal administration of oxytocin enhances trust, the oxytocin receptor (OXTR) gene is an excellent candidate to investigate genetic contributions to individual variations in trust behavior. Although a single-nucleotide polymorphism involving an adenine (A)/guanine (G) transition (rs53576) has been associated with socio-emotional phenotypes, its link to trust behavior is unclear. We combined genotyping of healthy male students (n = 108) with the administration of a trust game experiment. Our results show that a common occurring genetic variation (rs53576) in the OXTR gene is reliably associated with trust behavior rather than a general increase in trustworthy or risk behaviors. Individuals homozygous for the G allele (GG) showed higher trust behavior than individuals with A allele carriers (AA/AG). Although the molecular functionality of this polymorphism is still unknown, future research should clarify how the OXTR gene interacts with other genes and the environment in promoting socio-emotional behaviors.

We previously demonstrated with functional magnetic resonance imaging (fMRI) that religious belief depends upon three cognitive dimensions, which can be mapped to specific brain regions. In the present study, we considered these co-activated regions as nodes of three networks each one corresponding to a particular dimension, corresponding to each dimension and examined the causal flow within and between these networks to address two important hypotheses that remained untested in our previous work. First, we hypothesized that regions involved in theory of mind (ToM) are located upstream the causal flow and drive non-ToM regions, in line with theories attributing religion to the evolution of ToM. Second, we hypothesized that differences in directional connectivity are associated with differences in religiosity. To test these hypotheses, we performed a multivariate Granger causality-based directional connectivity analysis of fMRI data to demonstrate the causal flow within religious belief-related networks. Our results supported both hypotheses. Religious subjects preferentially activated a pathway from inferolateral to dorsomedial frontal cortex to monitor the intent and involvement of supernatural agents (SAs; intent-related ToM). Perception of SAs engaged pathways involved in fear regulation and affective ToM. Religious beliefs are founded both on propositional statements for doctrine, but also on episodic memory and imagery. Beliefs based on doctrine engaged a pathway from Broca's to Wernicke's language areas. Beliefs related to everyday life experiences engaged pathways involved in imagery. Beliefs implying less involved SAs and evoking imagery activated a pathway from right lateral temporal to occipital regions. This pathway was more active in non-religious compared to religious subjects, suggesting greater difficulty and procedural demands for imagining and processing the intent of SAs. Insights gained by Granger connectivity analysis inform us about the causal binding of individual regions activated during religious belief processing.

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Ketamine, a non-competitive N-methyl-d-aspartate receptor antagonist, is commonly used as an anesthetic and analgesic but has recently shown promising research in treating certain psychiatric conditions such as depression, post-traumatic stress disorder (PTSD), suicidal ideation, and substance use disorder. Due to its euphoric, dissociative, and hallucinogenic properties, ketamine has been abused as a recreational drug, which has led to rigid regulation of medication. The COVID-19 pandemic has been an unprecedented challenge for the American population which was reflected in increased reports of problems regarding their mental health. Mood disorders have dramatically increased in the past two years. Approximately one in ten people stated that they had started or increased substance use because of the COVID-19 pandemic. Furthermore, rates of suicidal ideation have significantly increased when compared to pre-pandemic levels, with more than twice the number of adults surveyed in 2018 indicating suicidal thoughts “within the last 30 days” at the time they were surveyed. Moreover, many responders indicated they had symptoms of PTSD. The PubMed database was searched using the keyword “ketamine,” in conjunction with “depression,” “suicidal ideation,” “substance use disorder,” and “post-traumatic stress disorder.” The inclusion criteria encompassed articles from 2017 to 2022 published in the English language that addressed the relationship between ketamine and mental health disorders. With this sharp increase in the prevalence of psychiatric disorders and an increased public interest in mental health combined with the promise of the therapeutic value of ketamine for certain mental health conditions, including suicidal ideation, this narrative review sought to identify recently published studies that describe the therapeutic uses of ketamine for mental health. Results of this review indicate that ketamine’s therapeutic effects offer a potential alternative treatment for depression, suicidal ideation, substance use disorders, and PTSD.

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