We have found support for the hypothesis that the interaction between the serotonin transporter gene and childhood maltreatment is specific to persistent forms of depression. Our results recommend attention to matching theory, methods, and measurements in the study of G×E, in the service of advancing knowledge about the origins of disease. We hope that the research reported here will stimulate further studies on this topic, including other genetic markers and novel designs. In particular, investigations focusing on G×E in the first onset of depression and assessing its predictive potential for future clinical course and response to treatment are needed to advance the current knowledge on the determinants of the individual differences in clinical course and outcomes of depression.
