What you carry at this position in your DNA and what research says about it.
Brain Health and Plasticity: 10/10 evidence, 95 publications.
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Sample genotype (not yours): C/C
Typical Brain Plasticity with Higher BMI Risk
Typical activity-dependent BDNF secretion and normal brain plasticity are maintained under this genotype. However, a slightly higher body mass index and increased risk of smoking initiation are also associated with this profile.
What this genotype means: Typical activity-dependent BDNF secretion; Better response to SSRI antidepressants; Slightly higher risk of elevated BMI and body weight.
Sample genotype (not yours): C/T
Reduced Brain Plasticity and Poorer Antidepressant Response
Reduced activity-dependent BDNF secretion occurs with this genotype, which may slightly impact memory consolidation and motor learning. It is also linked to a poorer response to certain SSRI antidepressants and a slightly higher risk of cognitive decline.
What this genotype means: Reduced activity-dependent BDNF secretion; Poorer response to SSRI antidepressants; Slightly increased risk of quicker cognitive decline.
Sample genotype (not yours): T/T
Lower BMI with Reduced Brain Plasticity
Significantly reduced activity-dependent BDNF secretion is linked to slower motor learning and quicker cognitive decline under this genotype. However, a lower body mass index and lower smoking risk are also strongly associated with this profile.
What this genotype means: Significantly reduced activity-dependent BDNF secretion; Lower average body mass index and body weight; Impaired motor learning and quicker cognitive decline.
Gene function and biological role
Gene Function: BDNF encodes brain-derived neurotrophic factor, a vital protein often called Miracle-Gro for the brain [1]. It supports the survival, growth, and maintenance of neurons [1]. BDNF is essential for synaptic plasticity, which allows brain connections to strengthen or weaken in response to learning and experience [2]. It also plays a key role in regulating mood, stress resilience, and energy homeostasis [1] [2].
Variant Impact: The rs6265 variant, known as Val66Met, changes the amino acid valine to methionine at codon 66 of the BDNF protein [1]. This molecular alteration interferes with the intracellular trafficking and packaging of BDNF into secretory vesicles [1]. As a result, activity-dependent secretion of BDNF is reduced by approximately 18% to 30% in carriers of the Met (T) allele [1] [3]. This reduction in available BDNF affects synaptic plasticity, memory formation, and susceptibility to cognitive decline [1] [3].
Key Insight: The Met (T) allele reduces activity-dependent BDNF secretion by up to 30%, which can slow down motor learning but may also offer a lower body mass index.
Location: BDNF. Chromosome 11 · 11p14.1 · 27.7 Mb
Estimated prevalence by population
Global 72.7%; European 66.1%; African 92.7%; East Asian 27.7%; South Asian 63.8%; Americas 70.7%; Ashkenazi 60.5%; Finnish 72.1%; Middle Eastern 71.6%; Amish 44.2%.
Estimated CC genotype frequency.
Global 24.2%; European 30.4%; African 7.2%; East Asian 49.9%; South Asian 32.2%; Americas 26.8%; Ashkenazi 34.6%; Finnish 25.6%; Middle Eastern 26.1%; Amish 44.6%.
Estimated CT genotype frequency.
Global 3.1%; European 3.5%; African 0.1%; East Asian 22.4%; South Asian 4.1%; Americas 2.5%; Ashkenazi 5.0%; Finnish 2.3%; Middle Eastern 2.4%; Amish 11.2%.
Estimated TT genotype frequency.
Showing effects for C/C genotype
Neurology & Mental Health
Cognitive Performance
Cognitive Decline. Evidence: 3/10. Source: PMID 28498887. Typical Rate.
Memory, Learning & Attention
Motor Skill Learning. Evidence: 3/10. Source: PMID 12553913. Typical Learning.
Addiction & Reward
Smoking Initiation. Evidence: 10/10. Source: PMID 30643251. Higher Risk.
Cardiovascular & Metabolic
Obesity & Body Composition
Body Mass Index. Evidence: 10/10. Source: PMID 19079260. Higher BMI Risk.
Pharmacogenomics
Antidepressant & Psychiatric Drug Response
Antidepressant Response. Evidence: 6/10. Source: PMID 25658497. Better SSRI Response.
Showing effects for C/T genotype
Cognitive Decline. Evidence: 3/10. Source: PMID 28498887. Quicker Decline.
Motor Skill Learning. Evidence: 3/10. Source: PMID 12553913. Slightly Impaired.
Smoking Initiation. Evidence: 10/10. Source: PMID 30643251. Typical Risk.
Body Mass Index. Evidence: 10/10. Source: PMID 19079260. Typical BMI.
Antidepressant Response. Evidence: 6/10. Source: PMID 25658497. Poorer SSRI Response.
Showing effects for T/T genotype
Motor Skill Learning. Evidence: 3/10. Source: PMID 12553913. Impaired Learning.
Smoking Initiation. Evidence: 10/10. Source: PMID 30643251. Lower Risk.
Body Mass Index. Evidence: 10/10. Source: PMID 19079260. Lower BMI.
What this genotype means for the people who carry it
Sample genotype: CC (Homozygous)
Normal secretion of brain-derived neurotrophic factor (BDNF) occurs in response to neuronal activity under this genotype [1]. This supports typical synaptic plasticity, memory consolidation, and motor skills learning [1]. Clinical studies indicate a better response to common SSRI antidepressants like escitalopram and sertraline [2]. On the other hand, large-scale genetic studies have linked the C allele to a higher body mass index and increased body weight [3]. Additionally, a higher likelihood of smoking initiation and increased daily cigarette consumption are associated with this genotype [4].
Typical activity-dependent BDNF secretion; Better response to SSRI antidepressants; Slightly higher risk of elevated BMI and body weight.
Sample genotype: CT (Heterozygous)
A heterozygous genotype results in an estimated 18% to 30% reduction in the activity-dependent secretion of BDNF [1]. This reduction can alter synaptic plasticity, making short-term motor learning and memory retention slightly more challenging [1]. Clinical studies suggest that carriers of this variant may experience a quicker rate of cognitive decline in neurodegenerative conditions such as Alzheimer's disease [2]. Furthermore, you may show a poorer therapeutic response to selective serotonin reuptake inhibitors (SSRIs) like paroxetine or sertraline [3]. However, your risk for elevated body mass index and smoking initiation is typical compared to the general population [4].
Reduced activity-dependent BDNF secretion; Poorer response to SSRI antidepressants; Slightly increased risk of quicker cognitive decline.
Sample genotype: TT (Homozygous)
A pronounced reduction in the activity-dependent release of BDNF in the brain characterizes this genotype [1]. This altered neuroplasticity is associated with impaired short-term motor skills learning and a faster rate of cognitive decline in late-life neurodegenerative disorders [2]. Poorer therapeutic response to standard SSRI antidepressants is also more common [3]. On the positive side, a significantly lower body mass index and reduced body weight are consistently linked to this genotype [4]. Additionally, a lower genetic predisposition for smoking initiation and daily cigarette consumption is observed [5].
Significantly reduced activity-dependent BDNF secretion; Lower average body mass index and body weight; Impaired motor learning and quicker cognitive decline.
Variants with shared genetic architecture
rs11030104 · BDNF Gene · Chr 11 · Weight and Joint Health
rs2030323 · BDNF Gene · Chr 11 · Weight and Appetite Control
rs2049045 · BDNF Gene · Chr 11 · Weight and Alcohol Risk
Content updated August 2026.
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