Catalepsy is a condition characterized most often by rigidity of the extremities and by decreased sensitivity to pain.

Professionals once believed this disorder was the result of (controllable) mental states that had no basis in physiology. Researchers now know, however, that catalepsy does not appear of its own accord; instead, it often manifests as one in a constellation of symptoms caused by disorders that have physical causes. Catalepsy can be produced by conditions as varied as Schizophrenia and Epilepsy, for example.

In some cases, isolated cataleptic instances can also be precipitated by extreme emotional shock.