up on meta-analysis 47,48. The reasons for these discrepancies are presently unknown, much debated, and critical to resolve. One important possibility is that current diagnostic categories pool genetically heterogeneous phenocopies, as has specifically been proposed in depression 49. If so, the use of biological endophenotypes, such as in the present study, can potentially aid the dissection of these populations into genetically and pathophysiologically more homogenous categories.
