According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), catatonia is defined by the presence of three or more of the following: (1) catalepsy (i.e., fixed and rigid posture), (2) waxy flexibility (i.e., slight and even resistance to repositioning by the examiner), (3) stupor (i.e., lack of psychomotor activity or reaction to the environment), (4) agitation, (5) mutism (i.e., lack of speech), (6) negativism (i.e., an opposite or contrary response to instructions), (7) posturing (i.e., active maintenance of posture), (8) mannerism (i.e., exaggerations of ordinary actions), (9) stereotypies (i.e., repetitive non-goal-directed movements), (10) grimacing, (11) echolalia (i.e., repeating the words spoken by another person), and (12) echopraxia (i.e., repeating the movements made by another person).

The diagnosis of catatonia can be made ...