catalepsy is a symptom of certain nervous disorders or conditions such as parkinson's disease and epilepsy. it is also a characteristic symptom of cocaine withdrawal. it may be caused by schizophrenia treatment with anti-psychotics such as haloperidol. it may be caused by the anaesthetic ketamine. in some cases, catalepsy may be started by an extreme emotional shock – one well known example of this was the reaction of 1968 olympic long jump medalist bob beamon on finding he had broken the previous world record by over 0.5 meters (2 feet). protein kinase a has been suggested as a mediator of cataleptic behavior.