As rrmoderator noted earlier in the discussion here, most ACIM groups appear to be fairly benign. I'd like to add here though, that on the individual level, I personally feel that there are some psychological concerns worth noting for those that jump head first into a deep study of the text.
First off, what is A Course in Miracles
? It's a book that was a combined project of Helen Schucman and William Thetford. It's claimed that Helen Schucman "channeled" the material and that William Thetford offered assistance and editing in the process. The channeled voice is not stated to be, but clearly speaks as if it's from Jesus.
Basically it's an East meets West book, combining some aspects of Eastern non-duality philosophy with some aspects of Western religion. This is fine and great as far as I'm concerned, but things get strange in ACIM.
According the Wikipedia entry on William Thetford
from 1951 to 1953 Thetford worked on Project BLUEBIRD, an early CIA mind control program that led to Project MKULTRA. ... From 1955 to 1957 he was an assistant professor of psychology at Cornell University's CIA-funded Society for the Investigation of Human Ecology. ... From 1971 to 1978 Thetford, along with David Saunders, headed the CIA mind control Project MKULTRA Subproject 130: Personality Theory.
William Thetford's wiki page even mentions that he hired Helen Schucman!
Perhaps that's from one part of their life, and their work on ACIM is another. But before even finding out about the authors, I felt uncomfortable with the book. I received ACIM as a gift not long ago.
In some ways, it offers very nice and flowery verses on non-dual philosophy and great verses on spiritual upliftment, which are wonderful for the philosophically-minded. But then things get dark. One moment, the reader is treated as a "child of God", for whom it is an honor for the author to serve with love and gentle guidance. In the next moment, the reader is berated as the cause of all the suffering of the world because of "bad thoughts". And it goes back and forth like this, like you're being subjected to "good cop, bad cop".
I started feeling disoriented, confused, and eagerly awaiting each new page in a feeling of dependence. I had to exercise a little personal control in discontinuing my reading. To ease my agitated mind, I did some simple "watching the breath" Zen-style breathing meditation. And that helped stabilize my mental state, to such an effective degree that I wanted to mention it here.
I then looked into information on the authors, and that's when I found the above material on the thought reform work that these two (or at the very least, one of them) were involved in. That apparently credible information combined with my own uncomfortable experience with the material, leads me to believe that there very well may be concerns with this widely distributed New Age classic.
Another suspicion is how ACIM was introduced to the public. The authors were never originally mentioned. People were encourage to make copies and freely distribute them. No one was told where it had come from.
So to me, that seems like people potentially involved in an experiment on the public, definitely in line with how those early CIA programs were run, without regard for the consequences to individuals. People were given massive doses of LSD without their knowing and without regard for the consequences (for those familiar with MKULTRA). So something like this wouldn't be out of character for people involved in such work.
Also of consideration, Helen Schucman the main author, a person presented as so spiritual as to be able to channel the thoughts of Jesus, was viewed by many as quick to anger. And from the eulogy written by Fr. Benedict J. Groeschel, C.F.R. at Helen Schucman's funeral:
"This woman who had written so eloquently that suffering really did not exist spent the last two years of her life in the blackest psychotic depression I have ever witnessed."