Commentary: gene by environment interplay and psychopathology--in search of a paradigm.

The articles in this Special Issue (SI) extend research on G×E in multiple ways, showing the growing importance of specifying kinds of G×E models (e.g., bioecological, susceptibility, stress-diathesis), incorporation of sophisticated ways of measuring types of G×E correlations (rGE), checking effects of statistical artifact, exemplifying an impressive range of quantitative and biological methodologies, and pointing to clearly needed next-step studies such as summarizing across many genes in gene sets (Bentley et al.) or in genome-wide pathway based approaches to G×E (Winham & Biernacka) and prediction of clinical outcomes (Rapee et al.). As a group, they document nicely that gene × environment research has come of age. What is the import of this? Does it represent a major new development in our field, or merely an incremental change of a framework that remains fundamentally unchanged?