"Brain zaps" and sensations
Symptoms described as "brain zaps", "brain shocks," "brain shivers" or "head shocks" are a withdrawal symptom experienced during discontinuation (or reduction of dose) of antidepressant drugs.[6][7] The symptoms are widely variable in description and of unknown etiology;[7] common descriptions include dizziness, electric shock-like sensations, sweating, nausea, insomnia, tremor, confusion, and vertigo.[6][7] The MedDRA "preferred term" for coding these types of symptoms in adverse drug reaction reports (for use in pharmacovigilance databases such as under the Yellow Card Scheme), is paraesthesia.[8][9]
In a 1997 survey, a "sizable minority" of medical professionals were not confidently aware of the existence of antidepressant withdrawal symptoms.[10] A 2005 review of adverse event reporting showed that descriptions of "electric shocks" from patients on paroxetine had been reported more frequently than some other symptoms.[8]