Castlewood Treatment Center and Hypnosis

"We don't use hypnosis," said Mark Schwartz, in an interview with ABCNews.com in 2011, but in this video featuring Schwartz, he clearly promotes the use of hypnosis in the treatment of eating disorders.

A psychologist accused of hypnotizing a woman into believing she possessed multiple personalities and participated in satanic rituals may be sued by several others who say they were also told they had been a part of a satanic cult, according to a Missouri attorney.

Lisa Nasseff, 41, of Saint Paul, Minn., is suing her former therapist, Mark Schwartz, and the Castlewood Treatment Center in St. Louis, Mo., where she received 15 months of treatment for anorexia, according to the complaint.

Instead of improving, the lawsuit alleges Nasseff suffered "great physical pain and suffering and anguish" during her time at the facility, and asserts that she will continue to suffer.

"She was hospitalized multiple times," Nasseff's lawyer, Kenneth Vuylsteke, told ABCNews.com. "One time she tried to commit suicide … she's done much better now that she's been away from there."

The complaint alleges Nasseff's therapist, Mark Schwartz, "carelessly and negligently hypnotized [Nasseff]" while she was under the influence of "various psychotropic medications" to treat depression and anxiety. The hypnosis allegedly created false memories, including the belief that she was "a member of a satanic cult and that she was involved in or perpetrated various criminal and horrific acts of abuse."

One of those acts included participating "in a ritualistic eating of babies," according to Vuylsteke.

Nasseff "was in a highly vulnerable physical and mental state due to her pre-existing eating disorder," according to the complaint.

The lawsuit also alleges Schwartz "persuaded and convinced [Nasseff] to become increasingly isolated from her family and friends by leading her to believe said persons were involved in a satanic cult and that they had been and would continue to sexually abuse her and force her to engage in criminal acts and horrific abuse of others."

But then other women receiving treatment at the facility began to realize their stories were very similar to one another's, Vuylsteke said.

"She got together with other women who had been through this with her at Castlewood. And they said, 'How can we all have been members of cults and not know it -- two years ago, three years ago? We all got brainwashed? It can't be right."

Now "multiple individuals" are speaking out about Castlewood, and backing Nasseff's account of what took place there, Vuylsteke added.

"We've got other cases we're looking at right now," Vuylsteke told ABCNews.com, adding the alleged victims' stories, all involving women, look "remarkably similar ."At this stage, he declined to say exactly how many women are claiming false memory implantation. "All I can tell you is it's several. We're in the process of evaluating them right now," he said.

Schwartz, the therapist who treated Nasseff at Castlewood and still serves as the facility's clinical co-director, denied ever hypnotizing Nasseff. "We don't use hypnosis," said Schwartz, who told ABCNews.com he has not yet retained a lawyer. "It's usually exposure therapy where the person is exposed to the memories of their trauma in various ways in order to move beyond it … A person is avoiding the memories and the feelings [associated with those memories] so you have them begin to talk about it in a safe way, that's not re-victimizing."

He also said he had never discussed satanic cults with Nasseff, and she had never told him she committed any criminal acts. "I don't know anything about all that," he said. He did confirm she had been given anti-depressants and that they had discussed "sexual trauma," but "the details I don't even remember." "She reported abuse history, we dealt with it, she got a lot better, and now she's suing us," he said. "Emotionally it hurts. You give everything you have to these clients and you really care about them. When they file a lawsuit it really stings."

On the Castlewood website, it states the treatment center's staff specializes in several areas, including hypnosis.

Castlewood Treatment Center did not respond to an interview request from ABCNews.com, but the executive director of the facility, Nancy Albus, told Courthouse News Service, "We strongly believe that all of these claims are without merit and we intend to defend these claims vigorously."

Implanted Memories at Castlewood?

According to the complaint, Nasseff stayed at Castlewood for about eight months, beginning in July of 2007. She later returned to the clinic in Mary of 2009 for an additional seven months of treatment before leaving the facility in December that same year.

In October of 2010, Schwartz allegedly contacted Nasseff, according to the lawsuit, and "told her if she did not return to Castlewood Treatment Center for additional psychological counseling and treatment she would most assuredly die from her eating disorder."

One year later, in October 2011, the complaint alleges Schwartz left Nasseff a telephone message saying her lawsuit would expose her multiple rapes, and her "membership in a satanic cult" as well as the individuals who were also members.

When asked about that phone call, Schwartz told ABCNews.com he had called Nasseff to say, "I'm worried about this because you told me a lot of information that is very, very confidential. When you file a lawsuit it all comes out, and it's a lot of secrets that you told me."

"It was really just concern," he said. "When people go to a therapist they expect confidentiality and privacy. It just breaks my heart that … she said a lot of horrible things that are going to come out."

The lawsuit claims Nasseff was "singled out and targeted" based, in part, on her "ability to pay for long-term continuous inpatient services."

She is now seeking $650,000 for the "medical, counseling and therapy treatment expenses" she incurred as a result of the alleged treatment, and $350,000 for non-economic costs, Vuylsteke said.

Vulnerable Patients Susceptible to Implanted Memories

Nasseff's lawyer, Vuylsteke, admitted he was skeptical when he first heard about Nasseff's case.

But then he met her in person.

"Lisa … is a highly intelligent individual," he said. "When I spoke with her I understood then what happened and what she had to work through to come to the realization that all of this was implanted."

He was further convinced after speaking with Bill Smoler, a prominent attorney from Madison, Wis., who is well-regarded among false memory experts. In January Smoler won a $1 million verdict for the parents of a girl who accused them of abuse after receiving inpatient therapy, and will be joining Nasseff's case as co-counsel, Vuylsteke said.

There's no credible scientific evidence that the human brain can store "repressed memories," according to University of California at Irvine professor Elizabeth Loftus, one of the country's foremost experts on false memory.

But psychologists have demonstrated it's possible to implant memories.

"In my research we plant false memories in the minds of people in order to study the process," she said. "There have been hundreds of cases … where people have gone into therapy and were led to believe they were molested."

It's a problem that emerged in the '80s and '90s, according to the False Memory Foundation, an organization founded in 1992 after a spate of cases where adults claimed to have uncovered "repressed memories" of childhood sexual abuse during therapy sessions. The revelations, however, weren't true.

"They were just exploding at that time," said False Memory Foundation co-founder Pamela Freyd, adding that the cases often involved inpatients participating in both hypnosis and support groups while on medication.

Chris Barden, a psychologist and attorney based in Minnesota was at the helm of many of those cases.

"During the 1990s I conducted more lawsuits against 'recovered memory' therapists than, I believe, any other lawyer in the world … for a total near 300 in over 30 states," he told ABCNews.com. "I won all but one of them."

The False Memory Foundation website states false memories "can result from the influence of external factors, such as the opinion of an authority figure or information repeated in the culture. An individual with an internal desire to please, to get better or to conform can easily be affected by such influences."

For intelligent, creative people with imaginations, Freyd said, "it may be easier for them to conjure up the kinds of images that develop in this kind of environment." But anyone seeking therapy is already in a vulnerable position, she added, and susceptible to persuasion.

"You believe the person you are seeing is an expert who will help you return to normal, you are going to try to do what this expert says needs to be done," said Freyd. "And if an expert says you need to recover memories, people who want to get better or be sure they're doing what the doctor says will work in that direction."

Steven Lynn, a memory expert and professor of psychology at Binghamton University in New York, told ABCNews.com it's possible to implant "all kinds of things."

"There's research showing you can implant memories of witnessing a demonic possession," he said.

Schwartz denied having implanted Nasseff's memories, but he did say he practices exposure therapy, which is typically used as treatment for people who have PTSD, according to Lynn. "The idea is that you present the person with imagined themes that have occurred in the past that tend to bring forth anxiety and symptoms of post traumatic stress disorder," Lynn said. "So by repeating exposure to the theme people learn how to not be so afraid of the situation they were formerly fearful of."

Exposure therapy can yield positive results in the right setting. But if someone has not actually been exposed to the traumatic event they're asked to re-imagine, exposure therapy can have a much different effect, Loftus said.

"If you take a group of women who have been raped and have them contemplate their legitimate rape experience then pretty soon many of them will be able to think about it without feeling as much emotion and pain," said Loftus. "But if you're exposing somebody to something that didn't happen then something completely different is going on."