Background: Lack of social support is an established risk factor across health outcomes, making it important to examine its family environmental and genetic determinants.

Methods: In a 27-year follow-up of the Young Finns Study (N = 2341), we examined with a latent growth curve model whether genes involved in the oxytocin signaling pathway namely, oxytocin receptor gene (OXTR) variants rs1042778, rs2254298, and rs53576-moderate the effect of early-life social experiences on perceived social support across the life span. Mothers reported the emotional warmth and acceptance towards their children at baseline when the participants were from 3 to 18 years old (1980). Perceived family support and support from friends and peripheral sources were assessed in five follow-ups 18 years apart (1989-2007).

Results: Maternal emotional warmth and acceptance predicted the initial level of perceived social support across subscales, while the rate of change in family support was affected by the family environment only if participants carried the T-allele of OXTR rsl 042778. This gene-environment interaction was not found for the rate of change in support from friends and peripheral sources and we also did not find associations between latent growth in perceived social support and OXTR variants rs53576 and rs2254298.

Limitations: Selective attrition in perceived social support, maternal emotional warmth and acceptance, gender, and SES. Family environment was assessed by a non-standardized measure.

Conclusions: OXTR rs1042778 polymorphism seems to contribute to changes in perceived family support in that way that some individuals (T-allele carriers) 'recover', to some extent, from the effects of early-life social experiences, whereas others (G/G genotype carriers) do not.