Therapygenetics: the 5HTTLPR and response to psychological therapy

Whilst pharmacogenetic research thrives1, genetic determinants of response to purely psychotherapeutic treatments remain unexplored. In a sample of children undergoing Cognitive Behavior Therapy (CBT) for an anxiety disorder, we tested whether treatment response is associated with the serotonin transporter gene promoter region (5HTTLPR), previously shown to moderate environmental influences on depression. Children with the short-short genotype were significantly more likely to respond to CBT than those carrying a long allele. There is considerable evidence of association between anxiety/depression and the 5HTTLPR, particularly in response to stress2. Moreover, the low expression S allele, typically associated with poorer outcomes following stress, is also associated with better outcomes under low stress and may reflect sensitivity to the environment3. We hypothesized that this allele would be associated with enhanced response to psychological therapies4. We collected DNA from 584 anxiety-disordered children aged 6-13 years, undergoing manual-based CBT5 at research clinics in Sydney, Australia and Reading, UK. We focus on 359 children with 4 white European grandparents (entire sample findings similar; se