Two patients present in a profound stupor, barely responsive to their surroundings. Before revealing the answer, name the bedside features you would check to tell catatonic stupor apart from depressive stupor.

Check facial expression (deadpan and blank in catatonic stupor, versus a depressed, miserable expression in depressive stupor), muscle tone (altered — increased, fluctuating, or in rare cases flaccid — in catatonic stupor, versus normal tone in depressive stupor), the presence of catalepsy or stereotypies (typical of catatonic stupor, not of depressive stupor), and incontinence (common in catatonic stupor, not typical of depressive stupor). Taken together, these four bedside observations reliably separate the two.