I’m not sure to what degree this counts as history of psychology, but it stuck me as an important psychology-related finding none the less. From a short article in the latest issue of the APA’s Monitor on Psychology (June, 2008, p. 12):
In a study of 62 police officers, researchers at Rosalind Franklin University of Medical Science in Chicago and the University of Illinois found that police officers who had been “tased” during training drills fared worse than a control group in attention, processing speed, and memory…. “It is a provocative finding because the kinds of dificulties that were observed… are the same kinds of changes we see in people who have suffered electrical shocks from accidents involving domestic power sources,” [co-author Neil] Pliskin says.
I suppose the exact same questions might be asked about electro-convulsive therapy, about which there has been heated debate concerning its cognitive side-effects for decades (and there is the connection with history of psychology, if you still yearned for one). If psychiatry was ultimately motivated to turn down the power with respect to ECT in order to avoid dramatic side-effects, perhaps the same considerations should go into an evaluation of the safety of stun guns as well.