BDNF genotype moderates the relation between physical activity and depressive symptoms.
OBJECTIVE
To test whether the BDNF gene interacts with exercise to predict depressive symptoms. Physical activity is associated with a range of positive health outcomes, including fewer depressive symptoms. One plausible mechanism underlying these findings involves Brain-Derived Neurotrophic Factor (BDNF), a protein hypothesized to limit or repair the damage caused by stress. Physical activity increases expression of BDNF, which may enhance brain health. BDNF expression is controlled by the BDNF gene. Compared with individuals without a BDNF met allele, met-allele carriers have a lower expression of BDNF, which has been associated with Major Depressive Disorder.


METHODS
Eighty-two healthy adolescent girls were genotyped for the BDNF val66met polymorphism, and their depressive symptoms and physical activity were assessed using questionnaires.


METHODS
BDNF genotype, Children's Depression Inventory, and the Physical Activity Questionnaire for Older Children and Adolescents.


RESULTS
The BDNF polymorphism was found to moderate the relation between exercise and depressive symptoms: being physically active was protective for girls with a BDNF met allele (fewer depressive symptoms) but not for girls with the val/val polymorphism.


CONCLUSIONS
By integrating psychological and biological factors, the present study enhances our understanding of how physical activity contributes to resilience to psychopathology.
Department of Psychology, Stanford University, USA. jumata@stanford.edu
Jutta
J
Mata
Renee J
RJ
Thompson
Ian H
IH
Gotlib
D000293:Adolescent; D000483:Alleles; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D002648:Child; D003863:Depression / Q000235:genetics* / Q000523:psychology; D015444:Exercise / Q000523:psychology*; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D005838:Genotype; D006801:Humans; D009043:Motor Activity / Q000235:genetics*; D010555:Personality Inventory; D011110:Polymorphism, Genetic / Q000235:genetics*
D019208:Brain-Derived Neurotrophic Factor