At one time, Suzanne Segal was a teacher of Transcendental Meditation. My wife knew Suzanne when she was a TM teacher. My wife was envious of her charisma and competence.
In childhood, Suzanne had moments of psychological detachment and “vastness” which would scare her.
Suzanne experienced an emotional trauma on her TM-Sidhis course when she received a letter from her fiancé that called off their engagement and informed her that he was going to go on the Purusha course. Purusha is the celibate monk-like program of the TM organization.
After she learned the TM-Sidhis, she told Maharishi Mahesh Yogi that when transcending she sometimes experienced great fear as if she was going to die. Maharishi laughed and told her not to worry and to just let go.
Unhappy with her experiences and with the direction of the TM movement, Suzanne soon fled from the TM organization, from TM knowledge, and from the practice of TM and the TM-Sidhis.
In 1982 while getting onto a bus in Paris she had a major shift in awareness and lost her sense of self. Since she understood the witnessing experience of Cosmic Consciousness as described by Maharishi, she sometimes described her experience as witnessing. However, at first, she was having a hellish, fearful experience so she couldn’t reconcile her experience with Cosmic Consciousness.
At the urging of her brother, Suzanne met with another TM teacher who had announced his own enlightenment but was actually having his own mental health crisis. The blind leading the blind is an apt statement. The “enlightened” TM teacher at first sensed a high state of consciousness in Suzanne and thought he could help her. Weeks later their relationship ended when he stated that she was evil because she was Jewish.
As time passed, Suzanne was able to function with seeming normalcy although she still did not have a sense of self. She completed a Ph.D. in Psychology in 1991 and continued to research her own condition.
Suzanne consulted with various psychologists and psychiatrists over the years. Though she was told by one that she had Depersonalization Disorder, she did not think it was a perfect fit because she was able to function normally in everyday life despite the loss of her individual self.
She also consulted with Buddhist teachers in California. Buddhism cultivates loss of ego, and some Buddhist teachers congratulated her on attaining moksha.
About 1994 Suzanne experienced another shift in consciousness in which there was a sense of unity between herself and the world.
In 1995, Suzanne’s story spread. She was reluctant to act as a spiritual teacher, but she agreed to meet with friends of her book editor. Within a few months of subsequent gatherings, several hundred people were attending meetings to hear her story and to ask her questions.
Suzanne’s autobiography, Collision with the Infinite, came out in 1996. She began training therapists and continued weekly gatherings for dialogues with spiritual enthusiasts.
In late spring 1996, she began having intense experiences of vastness which disrupted her life and exhausted her. In fall 1996, Suzanne recovered experiences of childhood abuse and was going through counseling treatment.
In early 1997, Suzanne’s mental faculties quickly deteriorated. Doctors discovered a malignant brain tumor which they removed. Suzanne refused further treatment and died on April 1, 1997 at 42 years old.
Wikipedia has a good summary of Suzanne’s amazing life at https://en.wikipedia.org/wiki/Suzanne_Segal.
Conclusion
The supposed experiences of enlightenment are so close to psychosis that Suzanne had a hard time deciding if she was enlightened or psychotic. Similarly gurus, psychologists, and psychiatrists had difficulty assessing Suzanne; some thought she was enlightened.
I think that a state of enlightenment does not exist. However there are altered states of consciousness that make people think that they are enlightened.
My Enlightenment Delusion 