Endophenotypes were originally described as internal phenotypes that mediate on the path between genes and the diseases genes moderate.16, 17 Their fundamental relevance was related to, but not necessarily dependent on, the assumption that endophenotypes represent less complex clues to genetic underpinnings than the disease syndrome itself, promoting the view that psychiatric diagnoses can be optimally deconstructed, resulting in more straightforward and successful genetic analysis.17, 18
