Article 1 BDNF 1 COMT 1 DNA 1 Quebec 1 adolescent 1 adult 1 allele 1 brain derived neurotrophic factor 1 brain development 1 catechol methyltransferase 1 child 1 controlled study 1 correlational study 1 disease predisposition 1 distress syndrome 1 environmental factor 1 female 1 gene-by-environment interactions 1 genetic variability 1 genotype 1 genotype environment interaction 1 heterozygote 1 hippocampal volume 1 hippocampal volumes 1 homozygote 1 human 1 ice storm male 1 maternal stress 1