NCAM1 and major depressive disorder: While the endpoint effector pathway has not yet been identified for the PFC, in the hippocampus, the expression of the cell adhesion protein PSA-NCAM has been proven to decrease in rodent models of depression-like behaviors, while the effectiveness of antidepressants correlates with increased PSA-NCAM in the hippocampus (Wainwright and Galea, 2013).