What is the disease Stiles have in Teen Wolf?

In "Teen Wolf," Stiles Stilinski is revealed to have a form of obsessive-compulsive disorder (OCD), which significantly affects his behavior and thought processes throughout the series. Additionally, in later seasons, he is possessed by the Nogitsune, a dark spirit that exacerbates his mental struggles and leads to chaotic and dangerous situations. This possession showcases the intertwining of his psychological issues with supernatural elements in the show's narrative.