Dopamine and Serotonin Transporter Genes Regulation in Highly Sensitive Individuals during Stressful Conditions: A Focus on Genetics and Epigenetics.

Background: Coping with stress is essential for mental well-being and can be critical for highly sensitive individuals, characterized by a deeper perception and processing of stimuli. So far, the molecular bases characterizing high-sensitivity traits have not been completely investigated and gene × environment interactions might play a key role in making some people more susceptible than others. Methods: In this study, 104 young adult university students, subjects that might face overwhelming experiences more than others, were evaluated for the genetics and epigenetics of dopamine (DAT1) and serotonin (SERT) transporter genes, in addition to the expression of miR-132, miR-491, miR-16, and miR-135. Results: We found an increase in DNA methylation at one specific CpG site at DAT1 5'UTR in highly sensitive students reporting high levels of perceived stress when compared to those less sensitive and/or less stressed. Moreover, considering DAT1 VNTR at 3'UTR, we observed that this effect was even more pronounced in university students having the 9/9 genotype when compared to those with the 9/10 genotype. These data are corroborated by the higher levels of miR-491, targeting DAT1, in highly sensitive subjects with high levels of perceived stress. SERT gene DNA methylation at one specific CpG site was reported to instead be higher in subjects reporting lower perceived stress when compared to more stressed subjects. Consistently, miR-135 expression, regulating SERT, was lower in subjects with higher perceived stress. Conclusions: We here suggest that the correlation of DAT1 and SERT genetic and epigenetic data with the analysis of stress and sensitivity might be useful to suggest possible biomarkers to monitor mental health wellness in vulnerable subjects.

From inner to dyadic connection: the role of mindfulness in mother-infant interaction during the first year of life.

Introduction: Mother-infant attunement is fundamental to supporting infant socio-emotional development. Based on the assumption that we connect better with others if we are aware of and connected with our own experience, mindfulness could affect the maternal ability to attune to the infant. However, little is known about this topic in the first year of life. Study 1 aimed to investigate the role of maternal dispositional mindfulness and mindful parenting in mother-infant physiological and behavioral attunement at 3 months of age. Study 2 aimed to explore the effect of a mindfulness-based intervention not specific to parenting experience on mother-infant behavioral and physiological attunement and on maternal wellbeing at 9 months of age. Methods: In Study 1, mother-infant (n = 67) behavioral and physiological attunement (i.e., co-regulation and RSA) were collected simultaneously each 20 s during face-to-face interaction. Mothers completed questionnaires about their dispositional mindfulness and mindful parenting. In Study 2, mother-infant dyads were randomly divided into a control (n = 20) and an intervention group (n = 29). The intervention group attended a 5-week mindfulness-based intervention. At T1 and T2, the same procedure described in Study 1 was applied and mothers reported about their wellbeing. Results: Results showed that maternal mindfulness was associated with high physiological and behavioral attunement at 3 months and with more positive maternal behaviors and less stress at 9 months. Analysis evidenced a slight improvement in the intervention group in maternal dispositional mindfulness and a reduction in parenting stress at T2. Discussion: Findings from both studies suggested that maternal mindfulness could represent a protective factor that could support mothers in fostering better dyadic interactions with their infants. The implementation of mindfulness-based interventions for mothers could have preventive and clinical implications.

Early, typical, and late talkers: an exploratory study on predictors of language development in the first two years of life.

Background: The consensus in scientific literature is that each child undergoes a unique linguistic development path, albeit with shared developmental stages. Some children excel or lag behind their peers in language skills. Consequently, a key challenge in language acquisition research is pinpointing factors influencing individual differences in language development. Methods: We observed children longitudinally from 3 to 24 months of life to explore early predictors of vocabulary size. Based on the productive vocabulary size of children at 24 months, 30 children met our sample selection criteria: 10 late talkers and 10 early talkers, and we compared them with 10 typical talkers. We evaluated interactive behaviors at 3, 6, 9 and 12 months, considering vocal production, gaze at mother's face, and gestural production during mother-child interactions, and we considered mothers' report of children's actions and gestures and receptive-vocabulary size at 15 and 18 months. Results: Results indicated early precursors of language outcome at 24 months identifiable as early as 3 months in vocal productions, 6 months for gaze at mother's face and 12 months for gestural productions. Conclusions: Our research highlights both theoretical and practical implications. Theoretically, identifying the early indicators of belonging to the group of late or early talkers underscores the significant role of this developmental period for future studies. On a practical note, our findings emphasize the crucial need for early investigations to identify predictors of vocabulary development before the typical age at which lexical delay is identified.

Moderate cardiac vagal tone predicts more cooperation in highly sensitive individuals.

Cooperation, as a mutual collaboration, is a defining feature of human social life. Individual characteristics can influence cooperation. Recent studies have shown a quadratic relationship between cardiac vagal tone (CVT), an index of self-regulation, and prosocial behaviors. Individual differences in cooperation might also vary as a function of people's environmental sensitivity (ES), i.e., may be influenced by individual differences in the perception and processing of inner and external stimuli. We tested the direct and interactive effect of CVT and ES on cooperative behaviors in two independent samples. We measured heart rate and engagement in cooperative acts in 80 young adults (M = 23.61; SD = 1.60) who were also asked to self-report on ES. We found an inverted-U relationship between CVT and cooperative behaviors. ES, on the other hand, did not predict differences in cooperative behaviors but moderated the relationships between CVT and cooperation, although the magnitude of this result was small. Specifically, only among individuals with higher ES cooperative behaviors change as a function of CVT. Highly sensitive individuals with lower or higher CVT, were less cooperative than low sensitive ones. Subsequently, we replicated the same study design in a second sample of 88 undergraduate students (M = 23.69; SD = 4.91). Once again, we found evidence supporting the presence of an inverted-U relationship between CVT and cooperative behaviors, and we also found that ES moderated the relationships between the quadratic CVT term and cooperation.

The role of environmental sensitivity in the experience and processing of emotions: implications for well-being.

Several theories suggest that people differ significantly in their environmental sensitivity, defined as the capacity to perceive and process information about the environment. More sensitive people, who make up between 25% and 30% of the population, are not only more negatively affected by adverse experiences but also benefit disproportionately from positive ones, in line with differential susceptibility theory. Heightened emotional reactivity has been identified as one of the key markers of sensitivity. However, the current understanding of the relationship between sensitivity and the experience and processing of emotions remains limited. In the current paper we propose a new conceptual framework for the multiple ways in which environmental sensitivity may impact on different aspects of the experience and processing of emotions. This includes heightened perception of emotions, increased emotional reactivity, as well as the important role of emotion regulation for the well-being of highly sensitive people. In addition, we also consider rearing experiences in shaping sensitivity and emotion regulation. The reviewed empirical studies largely support the conceptual model but more research is needed to explore the dynamics between sensitivity and emotions further. Finally, we discuss several implications for well-being before making a case for the inclusion of individual differences in environmental sensitivity in affective science. This article is part of the theme issue 'Sensing and feeling: an integrative approach to sensory processing and emotional experience'.

Longitudinal Profiles of Cultural Identity Processes and Associations with Psychosocial Outcomes Among Adolescents Participating in the Identity Project in Italy.

Cultural identity formation is a complex developmental task that influences adolescents' adjustment. However, less is known about individual variations in trajectories of cultural identity processes and how they relate to youth psychosocial outcomes. Using a person-centered approach, this study investigated patterns of change over a year in cultural identity exploration and resolution, respectively, among ethnically diverse adolescents in Italy. The sample included 173 high school students (Mage = 15 yrs, SD = 0.62, range = 14-17; 58.4% female; 26% immigrant background) who had participated in the Identity Project, a school-based intervention targeting ethnic-racial identity development. Longitudinal latent profile analysis revealed only one profile of change for exploration, whereas four unique profiles for resolution emerged ("stable low," "stable average," "increase low-to-average," "increase high-to-higher"). Overall, youth in the resolution-increase profiles reported the best outcomes. The findings highlight the heterogeneity of adolescents' resolution trajectories and the benefits of an increased sense of clarity concerning one's cultural identity for positive psychosocial functioning.

A Bayesian approach for exploring person × environment interaction within the environmental sensitivity meta-framework.

BACKGROUND: For investigating the individual-environment interplay and individual differences in response to environmental exposures as captured by models of environmental sensitivity including Diathesis-stress, Differential Susceptibility, and Vantage Sensitivity, over the last few years, a series of statistical guidelines have been proposed. However, available solutions suffer of computational problems especially relevant when sample size is not sufficiently large, a common condition in observational and clinical studies. METHOD: In the current contribution, we propose a Bayesian solution for estimating interaction parameters via Monte Carlo Markov Chains (MCMC), adapting Widaman et al. (Psychological Methods, 17, 2012, 615) Nonlinear Least Squares (NLS) approach. RESULTS: Findings from an applied exemplification and a simulation study showed that with relatively big samples both MCMC and NLS estimates converged on the same results. Conversely, MCMC clearly outperformed NLS, resolving estimation problems and providing more accurate estimates, particularly with small samples and greater residual variance. CONCLUSIONS: As the body of research exploring the interplay between individual and environmental variables grows, enabling predictions regarding the form of interaction and the extent of effects, the Bayesian approach could emerge as a feasible and readily applicable solution to numerous computational challenges inherent in existing frequentist methods. This approach holds promise for enhancing the trustworthiness of research outcomes, thereby impacting clinical and applied understanding.

The role of environmental sensitivity in the mental health of Syrian refugee children: a multi-level analysis.

Individuals with high environmental sensitivity have nervous systems that are disproportionately receptive to both the protective and imperilling aspects of the environment, suggesting their mental health is strongly context-dependent. However, there have been few consolidated attempts to examine putative markers of sensitivity, across different levels of analysis, within a single cohort of individuals with high-priority mental health needs. Here, we examine psychological (self-report), physiological (hair hormones) and genetic (polygenic scores) markers of sensitivity in a large cohort of 1591 Syrian refugee children across two waves of data. Child-caregiver dyads were recruited from informal tented settlements in Lebanon, and completed a battery of psychological instruments at baseline and follow-up (12 months apart). Univariate and multivariate Bayesian linear mixed models were used to examine a) the interrelationships between markers of sensitivity and b) the ability of sensitivity markers to predict anxiety, depression, post-traumatic stress disorder, and externalising behaviour. Self-reported sensitivity (using the Highly Sensitive Child Scale) significantly predicted a higher burden of all forms of mental illness across both waves, however, there were no significant cross-lagged pathways. Physiological and genetic markers were not stably predictive of self-reported sensitivity, and failed to similarly predict mental health outcomes. The measurement of environmental sensitivity may have significant implications for identifying and treating mental illness, especially amongst vulnerable populations, but clinical utility is currently limited to self-report assessment.

Maternal dispositional mindfulness and mother-child relationship: The mediating role of emotional control during parenting.

BACKGROUND: The literature supports the role of parental dispositional mindfulness on parent-child relationship quality. However, little is known about the connection between these two aspects. OBJECTIVE: The aim of this study was to investigate whether emotion regulation during parenting, that is, the ability to control negative emotions, mediated the association between parental dispositional mindfulness and parent-child relationship quality. The study also explored the moderation role of child age on the association between parental dispositional mindfulness and parent's ability to control negative emotions during parenting. METHODS: Participants were 635 mothers of children aged between 12 months and 5 years. Mothers completed self-report questionnaires to measure maternal dispositional mindfulness, mother-child relationship quality and maternal control of negative emotions during parenting. RESULTS: Results showed that maternal ability to control negative emotions during parenting partially mediated the association between maternal dispositional mindfulness and mother-child relationship quality. Moreover, the moderation role of child age indicated that the association between maternal dispositional mindfulness and maternal ability to control negative emotions during parenting was stronger for older children's mothers. CONCLUSION: Dispositional mindfulness has a protective role for the quality of parenting and the mother-child relationship. Theoretical and practical implications are discussed.

Family Functioning, Identity Commitments, and School Value among Ethnic Minority and Ethnic Majority Adolescents.

Ethnic minority youth show worse school adjustment than their ethnic majority peers. Yet, it remains unclear whether this gap can be explained by differences in family functioning and consequent identity commitments. This study examined (1) whether family functioning relates to identity commitments over time and (2) whether identity commitments impact later school value (3) among minority and majority adolescents. Minority (N = 205, Mage = 16.25 years, 31.1% girls) and majority adolescents (N = 480, Mage = 15.73 years, 47.9% girls) participated in this preregistered three-wave longitudinal study (T1: March-April 2012; T2: October 2012; T3: March-April 2013). Dynamic Panel Models revealed that most within-person cross-lagged associations were not significant in the total sample. Yet, multigroup analyses revealed differences between groups: Stronger identity commitments related to lower school value among minority adolescents, but were unrelated to school value among majority adolescents over time. Additionally, higher school value increased identity commitments among minority youth, yet it decreased identity commitments among majority youth over time. The findings highlight the differential interplay between identity commitments and school adjustment for minority and majority adolescents, with important implications for their future life chances.