Shock Treatment, more correctly known as ECT
or Electroconvulsive Therapy
is the process of passing electricity through a patient's brain, simulating/causing a small epileptic seizure
. The rationale behind this treatment is that certain mentally ill epileptics seemed to have a cessation of their mental symptoms after a seizure.
Literary links to this now largely discredited therapy are One Flew Over The Cuckoo's Nest by Ken Kesey and Zen and the Art of Motorcyle Maintenance by Robert M. Pirsig.