The Hinamizawa Syndrome (雛見沢症候群, Hinamizawa Shōkōgun) is a psychiatric disease found in Hinamizawa. It can cause anxiety and paranoia which can force the person to commit strange and violent acts, including suicide and murder. It has been seen in an immunization shot in Onikakushi-hen, Meakashi-hen and Tsumihoroboshi-hen. The symptoms of this disease are an amalgamation of real symptoms, including clawing out one's throat due to the sensation of insects crawling under their skin. Such a sensation is a real symptom called formication.