Ladouceur et al., 2007). To our knowledge, though, there have been no research studies to date that have looked at state changes in symptoms of depressed patients. Endophenotypes must also be heritable. Preliminary studies reported by Anohkin, Golosheykin, and Myers (2008) indicate that error-related brain activity is heritable, with estimates in the range of .30 to .50. Also, endophenotypes should be more evident in unaffected first-degree family members of patients compared to first-degree family members of non-patients. This has not been assessed, as of yet, and is certainly an important topic for future study.
