Genetic influences on anxiety in children: what we've learned and where we're heading.

Anxiety is a common problem, typically beginning early in life. This article explores reasons for individual differences in levels of anxiety among children, by reviewing the genetic literature. The plethora of research to date has demonstrated clearly that both genes and environmental influences play important roles in explaining differences in levels of anxiety of various types among children. This has encouraged researchers to search for specific genes and environmental influences upon anxiety. Despite important progress in identifying links between anxiety and specific genes--including associations between serotonin and dopamine genes and different symptoms of anxiety--overall, progress has been slow because multiple genes of small effect size are likely to influence anxiety. This article explains how the hunt for genes involved in anxiety is likely to benefit from genetically sensitive research, which examines the co-occurrence of symptoms; includes measures of the environment; and examines endophenotypes and risk pathways.