I do think that people involved in cults should be given mental help. And by cult, I mean all of the people who follow any prophet or scripture word for word. If you were to follow the koran or bible word for word, you'd be committing horrifying atroceties on a daily basis.
I've been saying that for years. Yes, people in cults should be given mental help. Of course, my idea of cults include Christianity and Islam. Just because they have lots of adherents doesn't make them any less of a cult. When people stop blowing up stuff in the name of Jesus or Mohammed, then I'll stop calling them cults full of mentally ill people.
If your looking for an answer and a cult is your choice, you need mental health treatment. I think if they decided that these kinds of people have the answer, they need deep sessions of one on one therapy. This is of course considering that they did't break any laws.
Cults are difficult enough to define. Once a sufficient definition of cults is created, then the behavior of its members must be considered individually. Not everyone in a cult is a true believer. Some cult members are just there supporting family and friends. This does not make them mentally unstable. This makes them socially dependent, but that is not uncommon enough to demand therapy.