In Cults in Our Midst, chapter 12, Margaret Singer writes:
Not all former cult members encounter all the problems listed on Table 12.1, nor do most have them in severe and extended form. Some individuals need only a few months to get themselves going again. After encountering some adjustment problems to life outside the cult, they make rather rapid and undeventful reintegrations into everyday life. Generally, however, it takes individuals anywhere from six to twenty-four months to get their lives functioning again at a level commensurate with their histories and talents. Even then, however, theat functioning may not reflect what is still going on insed them. Many are still sorting out the conflicts and harms that grew out their cult experience long after two years have gone by. Each former member wrestles with a number of problems. Some need more time than others to resolve all the issues they face, and a few never get their lives going again.
Then, she wrote:
Coming out of the cult pseudo-personality is about reeducation and growth. Self-help through reading can be invaluable for those who live far from knowledgeable resources such as exit-counselors, cult information specialists, former member support groups, and mental health professionals.
According to Margaret Singer, the time of recovery depends on the person. She did not write about 20 years or longer. Instead, she wrote about several months, 2 years or longer. In addition, she did not write that is is necessary to get a counseling or a therapy in order to recover.