The study of PCDH17 in the basal ganglia circuits has highlighted that PCDH17 KO mice show an antidepressant-like phenotype when challenged with a battery of behavioral tests aimed at evaluating cognition, anxiety, and depression [61], suggesting that this protein could play an important role not only in disease states conceptualized as neurodevelopmental disorders, such as the bipolar disorder, but also in depression that is a comorbid condition in people with neurodevelopmental disorders. This evidence concerns the gene PCDH17 and bipolar disorder.