The differences in developmental stages in genetic and environmental influences on family social support and depression in late childhood and adolescence

Depression is the second leading cause of disability in the world (Ferrari et al., 2013) and is the top cause of illness and disability among adolescents (WHO, 2016). Studies have shown the protective role of social support in... [ view full abstract ]

Depression is the second leading cause of disability in the world (Ferrari et al., 2013) and is the top cause of illness and disability among adolescents (WHO, 2016). Studies have shown the protective role of social support in helping prevent occurrence of depression in adolescence (Dingfelder et al., 2010). In order to prevent depression among children, it is necessary to pay attention to them even before they reach puberty. In this study, we examined the differences in developmental stages in genetic and environmental influences on maternal or paternal support and depression. A total of 530 twins took part in this study, and we divided them into late childhood (age 9–12 years) and adolescence (age 13–18 years) to compare the two developmental stages. The results of the correlated factor model showed that the magnitude of genetic effect seemed to be more important in adolescence than in late childhood, in the relationship between maternal support and depression. Moreover, the most interesting results were that in late childhood the phenotypic correlation (r = -.42, p < .01) between maternal support and depression was explained by shared common and unique environmental factors (r_c = -.53, which explains 60% of covariation; r_e = -.31, which explains 40% of covariation, respectively). In contrast, the phenotypic correlation (r = -.47, p < .01) between paternal support and depression was explained by shared genetic (r_g = -1.00, which explains 69% of covariation) and unique environmental (r_e = -.25, which explains 31% of covariation) factors. The present findings showed that genetic factors had a greater influence than did environmental factors on the relationship between maternal or paternal support and depression in adolescence. In late childhood, however, environmental factors had a greater influence than did genetic factors on the correlations between the variables of maternal support and depression. These results suggest that according to stages of development, it might be necessary to change contents and quality of support provided by mother and father for prevention of children's depression.