a1 Department of Child and Adolescent Psychiatry, University of Manchester, Royal Manchester Children's Hospital, Pendlebury, Manchester M27 4HA, UK
a2 Department of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff CF4 4XN, UK
Although there is some evidence to suggest that depressive symptoms show age-related changes, it remains uncertain as to whether there are also developmental variations in the etiology of depression. In this article, we present findings from a population-based study of twins aged 8 to 16 years with the aim of examining the genetic etiology of depressive symptoms and the effects of age. The results suggest that environmental factors influence the transmission of depressive symptoms in childhood. However depressive symptoms in adolescence appear to be highly heritable. The etiology of depressive symptoms was further explored using factor-derived scores that again suggested the importance of genetic factors in adolescence. However there was some suggestion that genetic influences may contribute to certain types of symptoms (self-deprecation/self-esteem) even in childhood.
c1 Anita Thapar, Department of Adolescent and Child Psychiatry, University of Manchester, Royal Manchester Children's Hospital, Pendlebury, Manchester M27 4HA UK