The project now has data on the temperament and adjustment of hundreds of children from infancy to adolescence, and in recent years the project has collected DNA from many participants. A goal of the project is to determine whether individual differences in temperament are associated with functional polymorphisms in genes such as the serotonin transporter gene. Polymorphisms in the regulatory region of this gene have been linked to anxiety and depression in adults. By influencing gene activity, the 'long' and 'short' variants may influence serotonin levels in the brain.
New research joins dozens of studies based on the Australian children's unique data.
Anthony Jorm, of the Australian National University in Canberra, and colleagues recently analyzed the serotonin transporter gene and data on anxiety and behavior problems in hundreds of subjects. No significant associations were found at most ages. Some teenagers who reported increased anxiety had two copies of the long variant, however. The reason for the discrepancy between the results is not clear. As with any association study, the data need to be replicated.