Background: Anxiety symptoms (AS) and depressive symptoms (DS) are associated during childhood, which could be accounted for by dynamic temporal interactions between the two sets of symptoms, as well as by shared etiological... [ view full abstract ]
Background: Anxiety symptoms (AS) and depressive symptoms (DS) are associated during childhood, which could be accounted for by dynamic temporal interactions between the two sets of symptoms, as well as by shared etiological features (Garber & Weersing, 2010). The present study aimed to document the longitudinal contributions between AS and DS by taking into account etiological factors in a normative sample of twins over the course of elementary school. Methods: 1112 twins were assessed by their teacher for AS and DS at 5 time-points from kindergarten to grade 6. A cross-lagged structural model was estimated to examine the cross-sectional associations as well as cross-lagged contributions between AS and DS. The etiology of the associations between AS and DS within and across ages was examined by fitting cross-lagged twin models (Burt, McGue, Krueger, & Iacono, 2005). Results: Most of the variance in AS (90.4%-96.6%) and DS (87.2-94.5%) was time-specific and more genetic in nature for DS (a2 = 33%/33.2%-50.5%/52.5%; e2 = 44%/44.6%-57%/56.2%) than AS (a2 = 21.7%-35.5%/35.9%; e2 = 68.7%-70.2%/70.9%). Previous DS (cross-age) best accounted for subsequent DS than cross-lag or previous common effects through both genetic and unique environmental influences, whereas AS from Kindergarten to Grade 3 was best accounted for by cross-lags from previous DS than cross-age or previous common effects through both common genetic and unique environment influences. Thereafter, previous AS contributed more to subsequent AS than cross-lag or previous common effects mainly through genetic influences. Conclusions: DS in the early school years appear central to the development of both AS and DS through cross-lag and cross-age genetic and unique environmental influences.
Burt, S. A., McGue, M., Krueger, R. F., & Iacono, W. G. (2005). How are parent-child conflict and childhood externalizing symptoms related over time? Results from a genetically informative cross-lagged study. Dev Psychopathol, 17(1), 145-165. doi:10.1017/S095457940505008X
Garber, J., & Weersing, V. R. (2010). Comorbidity of Anxiety and Depression in Youth: Implications for Treatment and Prevention. Clinical Psychology: Science and Practice, 17(4), 293-306. doi:10.1111/j.1468-2850.2010.01221.x
