The Role of Genotype-Environment Interactions in the Development of Symptoms of Anxiety and Depression in Stress Associated with Disease in a Family Member

The relationship between the 5-HTTLPR and BDNF Val66Met marker genotypes and symptoms of depression and anxiety associated with stress resulting from severe chronic illness in a family member was studied. Genotyping was performed in groups of 214 unaffected parents of patients with schizophrenia and 100 control subjects. The Met*ss diplotype was associated with increases in depressive tendencies (MMPI test) in the parents of patients but not in the control group, while among parents this was the case in the subgroup of parents whose children had the most severe symptoms. These results suggest that the interaction of polymorphic 5-HTT and BDNF genes may mediate the relationship between objective and subjective burden of disease.