Genetic Sensitivity Predicts Long-Term Psychological Benefits of a Relationship Education Program for Married Couples

Objective: Relationship education programs have proven effective in promoting relationship quality and preventing divorce among married couples. However, according to theories of Environmental Sensitivity, people differ for genetic reasons in their sensitivity to environmental influences with some more affected by both negative and positive experiences, including psychological interventions. Method: Here we test in two studies whether the positive effects of the established Prevention and Relationship Education Program (PREP) are moderated by two different polygenic scores (PGS) for environmental sensitivity, one based on nine established candidate genes and one based on several thousand variants across the genome, derived from recent genome-wide association study (GWAS) results. Analyses were conducted in a randomized controlled study on PREP (N = 242) and then repeated in an independent replication trial (N = 183). Results: Several significant PREP-X-PGS interactions indicated moderation of long-term treatment effects across the two studies, most of them involving the genome-wide score. Generally, higher genome-wide genetic sensitivity was associated with stronger intervention effects on almost all measures of relationship quality across the follow-up period. Conclusions: Findings provide further evidence that people differ substantially in their response to the positive effects of psychological intervention as a function of individual differences in genetic sensitivity, with more sensitive participants potentially benefitting more from relationship education. What is the public health significance of this article? This study provides new but preliminary evidence that people differ in their sensitivity to the positive effects of psychological intervention due to their genes. Higher genetic sensitivity was associated with a stronger positive response to an established relationship intervention. Biologically based differences in sensitivity may need to be considered as important factors in treatment response.