Use the adjective catatonic to describe someone who is in an unresponsive stupor, as if suffering from a mental disorder. Sometimes in the summer it gets so hot that people lose all their energy and get catatonic.
Catatonic can also be used to describe something that is related to psychiatric problems. Catatonic schizophrenia, for example, has symptoms that can include physical immobility, unresponsiveness, or strange movements. The weird thing about the word catatonic is that it can either mean not moving at all or moving in a frenzy — or it can mean having totally rigid muscles or having totally relaxed muscles.