An excellent introductory study of new religious movements in the United States (in the 1970s), by the sociologists Anson Shupe and David Bromley.

Their contention is that the so-called "cults" that they studied are really quite different from each other, and that there isn't a monolithic phenomenon known as "mind control" or "brainwashing" that attracts seekers to these movements. Indeed, they point out that the rates of attrition are so high that, even if they were all using "mind control," it is an ineffective technique.

A good job of sociological debunking.