Is BDNF destiny or just a small risk factor?

BDNF (brain-derived neurotrophic factor) is a gene involved in neuroplasticity. The common Val66Met (rs6265) variant is associated with a slightly increased risk for depression and memory decline, but the effect size is small. GWAS and meta-analyses show that BDNF explains only a tiny fraction of the variance; environment, lifestyle, and other genes matter far more. Calling BDNF 'destiny' would be misleading. A DNA test for this SNP is informational, not diagnostic. Even carriers of the risk allele can upregulate BDNF through exercise, diet, and stress reduction. The evidence is moderate (human-moderate), not strong enough for clinical decisions. Bottom line: BDNF is a small risk factor, not a deterministic fate.