Introduction

Anxiety disorders run in families. Children of anxious parents are prone to develop anxiety problems of their own, and parents of anxious children show more anxiety problems than parents of children without anxiety problems. This aggregation of anxiety in families can be due to common experiences as well as to common genes. Over the last two decades researchers have tried to disentangle the contributions of nature and nurture to the transmission of anxiety disorders. This chapter will review their research and their findings, as well as the new questions yielded.

The chapter has two sections. The first section, on the genetic contribution to anxiety in children, starts out with a brief review of the studies that have demonstrated that anxiety disorders aggregate in families. However, the studies show low specificity: children's anxiety disorders often do not coincide with those in the parents, and there appears to be overlap with other disorders, especially depression.

This is followed by a discussion of quantitative genetic studies, which addresses both genetic and environmental contributions to the transmission of anxiety disorders in families, and can shed light on questions of comorbidity. Most of this research has been conducted with adults, but findings from genetic research on anxiety disorders in children and adolescents are now emerging. These findings are both puzzling and intriguing – because different perspectives on the child's anxiety (parental report versus children's report) and different research designs (twin studies versus adoption studies) appear to yield contradictory findings.