From Wikipedia Religious Cult:
While most scholars no longer refer to any new religious movements as cults, some sociologists still favor retaining the word as it was used in church-sect typologies. For this value-neutral use of the word, please refer to new religious movements. Other scholars and non-academic researchers who use the word do so from explicitly critical perspectives which focus on the relationship between cult groups and the individual people who join them. These perspectives share the assumption that some form of coercive persuasion or mind control is used to recruit and maintain members by suppressing their ability to reason, think critically, and make choices in their own best interest. However, most social scientists believe that mind control theories have no scientific merit in relation to religious movements.

Mind control
Studies performed by those who believe that some religious groups do practice mind control have identified a number of key steps in coercive persuasion:
1. People are put in physical or emotionally distressing situations;
2. Their problems are reduced to one simple explanation, which is repeatedly emphasized;
3. They receive what seems to be unconditional love, acceptance, and attention from a charismatic leader or group;
4. They get a new identity based on the group;
5. They are subject to entrapment (isolation from friends, relatives and the mainstream culture) and their access to information is severely controlled.