Peripheral brain-derived neurotrophic factor in stable love relationships: a study in healthy humans

The study aimed to investigate whether involvement in a stable romantic partnership is associated with differences in peripheral brain-derived neurotrophic factor (BDNF) levels.

In a cross-sectional study, 60 healthy adults (32 women; mean age 27.4 ± 4.1 years) were classified as in a stable relationship (n = 31) or not (n = 29) after a clinical interview. Morning fasting blood was collected to quantify serum and platelet BDNF using a mature-BDNF sandwich ELISA. Data were analysed with t-tests and two-way ANOVA (group, sex), reporting effect sizes.

Participants in a relationship showed higher PLT-BDNF (4.36 ± 1.22 vs 2.85 ± 0.67 ng/mg; t(58) = 5.90, p < 0.001, d = 1.52) and higher serum BDNF (36.83 ± 6.95 vs 25.47 ± 5.23 ng/ml; t(58) = 7.12, p < 0.001, d = 1.84) than participants without a current stable romantic relationship. Two-way ANOVA confirmed a main effect of group for PLT-BDNF (F = 35.35, p < 0.001, η² = 0.39) and serum BDNF (F ≈ 50, p < 0.001, η²≈0.47), while the sex and group × sex interactions were not statistically significant for both PLT-BDNF and serum BDNF.

Our results would indicate that a stable romantic partnership is associated with higher intraplatelet and serum BDNF levels. These findings support an association between current committed romantic relationship status and peripheral BDNF measures in healthy adults.