Hunting genes, hunting endophenotypes.

Identifying specific genetic contributions to psychopathology has proved to be much more difficult than anticipated. In pursuit of this goal, Iacono and colleagues provide a remarkable set of studies that are important for the methods showcased as well as the findings reported. The immediate yield of positive findings is somewhat limited, but such an outcome is in fact quite informative. These papers will inspire further innovation and ambition in efforts to identify causal pathways to psychopathology and, more specifically, will increase emphasis on endophenotypes, a perspective highly compatible with the NIMH Research Domain Criteria (RDoC) initiative.