The normalized change in BDNF plasma level (natural log of BDNF post-retreat minus natural log of BDNF pre-retreat) was inversely correlated with BSI-18 anxiety scores at both the pre-retreat (r = 0.40, p < 0.05) and post-retreat (r = 0.52, p < 0.005) such that those with greater anxiety scores tended to evidence a smaller pre- to post-retreat increase in plasma BDNF levels. This evidence concerns the gene BDNF and Anxiety.