These quotes from one of the most respected therapists in ritual abuse, Alison Miller, give a good overview of this subject, from her book ― Healing the Unimaginable: Treating Ritual Abuse and Mind Control:

“What daily life is like for “a multiple”

Imagine that you have periods of “lost time.” You may find writings or drawings which you must have done, but do not remember producing. Perhaps you find child-sized clothing or toys in your home but have no children. You might also hear voices or babies crying in your head.

Imagine that you can never predict when you will be able to have certain knowledge or social skills, and your emotions and your energy level seem to change at the drop of a hat, and for no apparent reason.

You cannot understand why you feel what you feel, and, if you are in therapy, you cannot explore those feelings when asked. Your life feels disjointed and often confusing. It is a frightening experience. It feels out of control, and you probably think you are going crazy. That is what it is like to be multiple, and all of it is experienced by the ANPs.  [Alternate Personality]

A multiple may also experience very concrete problems, even life-threatening ones.”

…

“Since the 1980s, therapists have reported encountering clients or patients who had experienced extreme abuses featuring physical, sexual, emotional, spiritual, and cognitive aspects, along with a premeditated structure of torture-enforced lessons. The phenomena was first labeled “ritual abuse,” and, later, as our understanding developed, “mind control.”

“Those who are aware of their condition and experience themselves as “multiple” might refer to themselves as “we” rather than “I.” I shall use the term “multiple” at times, in respect for their internal experience. It is important to point out, however, that I recognize that someone who is multiple is actually a single fragmented person rather than many people. On the outside, a multiple is probably not visibly different from anyone else. But that image is only an imitation: people who are multiple cannot think like the rest of us, and we cannot think like them. (In fact, since it is difficult for the multiple to understand how singletons think, some of them might think that is is you who are strange).

Just as a singleton cannot become a multiple at will, a multiple cannot become a singleton until and unless the barriers between the parts of the self are removed. Those barriers were put up to enable the child to tolerate, and so survive, unavoidable abuse.

[Multiple: a person with dissociative identity disorder (DID) or DDNOS.
Singleton: a person without DID or DDNOS, i.e with a single, unified personality]”

…

“Programming is the act of installing internal, pre-established reactions to external stimuli so that a person will automatically react in a predetermined manner to things like an auditory, visual or tactile signal or perform a specific set of actions according to a date and/or time.”

…

“The first generation of therapists doing this work were told by their clients that the one massive cult was everywhere, knew everything, had access to state-of-the-art technology, and was willing to kill both clients and therapists to stop the information from getting out.”

“The reality is that even before stories of ritual abuse and mind control began coming out to therapists, the groups had agreed on what kind of disinformation to spread, so that clients would be afraid to tell their therapists what had happened to them, and therapists would be afraid to work with these clients.”

“Because the problem of ritual abuse and mind control has not gone away – the survivors are still there – many more therapists have learnt about it. Survivors have spoken out and written their stories, and therapists have learnt a great deal from those brave survivors who have discovered what was done to them. There is a large special interest group on Ritual Abuse and Mind Control within the International Society for the Study of Dissociation. Those therapists who have learnt in isolation or in small private online forums are once again sharing their knowledge widely, and books such as this one are beginning to be published again. The work is still very difficult and challenging, but we now know so much more than we did. We know that there is not one massive Satanic cult, but many different interrelated groups, including religious, military/political, and organized crime, using mind control on children and adult survivors. We know that there are effective treatments. We know that many of the paralyzing beliefs our clients lived by are the results of lies and tricks perpetrated by their abusers. And we know that, as therapists, we can combat this evil with wise and compassionate therapy.”

…

“A child who is being abused on an ongoing basis needs to be able to function despite the trauma that dominates his or her daily life. That becomes the job of at least one ANP [alternate personality], whom the child creates to be unaware of the abuse and also of the multiplicity, and to “pass as normal” in the real world. The ANP is just an alter specialized for handling the adult world—in other words, the “front person” for the system.”

…

“In fact, rather than being “more” than the others, the ANP is generally one that is very limited, with little power in the system, little memory of what happened, and limited energy or emotions.”

…

“It is unlikely that one ANP will serve as a constant throughout the person’s life. Your client is, therefore, likely to have others besides the ones you know, or several who you might think of as “the host”. Adults with dissociative disorders often have several ANPs from earlier stages of life inside. They usually have the same name but are of different ages. Sometimes, there are several current ANPs, each of whom assumes she or he is the “real” person and is amnesiac for the existence of the others. Their current knowledge and experience may overlap, while their other characteristics differ somewhat. This makes them glide easily from one to the other, and the therapist can easily miss the switch.”

…

“I remember one of my first ritually abused clients confessing to me that for a long time she had remembered being abducted by aliens, but had not told me because she did not want me to disbelieve her other memories because of it. We worked through the “alien abduction” memory and discovered that the “spaceship” was parked in the courtyard of the cult training center.”

…

“Besides stage magic props and settings, ritually abusing groups use technology, such as that described by Katz and Fotheringham. Military/political groups have the most sophisticated technologies, and much training or programming is now done with virtual reality equipment. Movies and holograms are used to deceive a child into believing in things that are unreal.

When a client says to you “I don’t know if it’s real; how can it be real?” remember that there are several options, not just two: (1) It happened just as s/he remembers; (2) it did not happen at all; (3) something happened, but due to technology and/or trickery it was not what s/he thinks it was; (4) the thought that the memory must be unreal is itself a program, as described in Chapter Twelve, “Maybe I made it up.”

…

“In my client who had confessed her “alien abduction” experience, an alter had been instructed that if she began to remember the ritual abuse she was to remember the alien abduction, so that nobody would believe her account of the ritual abuse. This program did not work with us, but you can imagine the larger consequences of such a ruse.”

― Alison Miller, Healing the Unimaginable: Treating Ritual Abuse and Mind Control