Yet despite this stigma, shock therapy – more properly known as electroconvulsive therapy or ECT – remains an accepted psychiatric treatment to this day, and has proven highly effective in cases of severe depression and bipolar disorder which have not responded to other treatments. But how was ECT invented in the first place, and how does it actually work? But while Insulin Shock Therapy boasted a success rate of 80%, it was a time and labour-intensive treatment, requiring a dedicated unit of doctors and nurses to administer. Thus, unlike Insulin Coma Therapy, a round of Metrazol therapy could be performed by a single doctor with a handful of nurses or orderlies to hold the patient still. By the 1940s Metrazol therapy had all but replaced Insulin in British psychiatric hospitals.