These MTFS papers represent the first comprehensive effort to examine the possible etiologic relevance of common and rare genetic polymorphisms for a wide range of psychophysiological endophenotypes using genome-wide and candidate-targeted methods applied to the largest sample employed for such a purpose to date. We make no claim that it is appropriate to generalize our conclusions to every possible variable that could be considered an endophenotype. However, given our results and the current state of the literature on psychiatric endophenotypes, in the absence of contrary evidence, we believe it is fair to apply our conclusions broadly. It is also worth noting that the variables we tested ranged in neurobiological complexity from being generated by networks of brain structures (e.g., EEG power spectra and P3) to those presumed to have simple underlying circuitry (e.g., startle). Regardless of the variable tested, our conclusions were largely the same. Considering our results across the seven empirical papers in this special issue, we offer the following conclusions.
