Genetics tied to emotional reactivity under stressful situations

A recent study published in The Scientific Reports examined the link between genetic variations in the CD38 gene cluster and heightened distress during emotionally charged situations

Oxytocin is a peptide neurohormone that is actively involved in social behavior, including parent-infant bonding, particularly in the immediate period following childbirth, relationships, and group dynamics. Oxytocin-related genetic variants have been associated with various effects on empathy, brain activation during emotion recognition tasks, responses to trauma, and the risk of autism.

Researchers have identified that A allele carriers of the CD38 single nucleotide polymorphism (SNP) had higher plasma oxytocin levels, a more sensitive approach to parenting, and stronger empathic responses. However, other studies have reported that individuals with the AA genotype of the CD38 SNP reported higher levels of suicide ideation, depressive symptoms, and greater alienation from parents and peers.

For the study, university students aged 18 and older with the AA, AC, and CC genotypes of the CD38 SNP were recruited and were asked to watch a three-minute video in which a father shared the story of his child's battle with terminal cancer. The participants were then required to complete a questionnaire designed to assess their emotional responses to 12 emotions, six involving feelings of empathic concern and the remaining six encompassing feelings of personal distress. The responses were rated on a scale from one to five, with higher scores indicating higher endorsement of the emotional response.

Two Interpersonal Reactivity Index (IRI) subscales, including the personal distress and empathic concern subscales, were used to explore whether the CD38 genotype related to dispositional measures of emotional responses.

The findings revealed that the average distress-related response ratings were higher for females or AA/AC genotypes than for males or CC genotypes, thus suggesting that sex and CD38 genotype affected these responses but not their interaction. Females also scored higher than males on empathy-related responses; however, these scores were not significantly different among the different genotypes.

Reference: Procyshyn, T. L., Leclerc Bédard, L., Crespi, B. J., & Bartz, J. A. (2024). CD38 genetic variation is associated with increased personal distress to an emotional stimulus. Scientific Reports 14(1); 1-7. doi:10.1038/s41598-024-53081-5