This may sound contradictory but the nature of your dreams may be changing because you are improving psychologically. From a psychoanalytic perspective, the unconscious mind blocks memories that are too psychologically painful. This is a defense mechanism called repression. Repression protects an individual from thoughts or memories that are too painful to deal with consciously. As M. Scott Peck explains, we “have a conscious mind that is so often unwilling to face [difficult feelings and memories] and tolerate the pain of dealing with them, and that is so willing to sweep them under the rug.”
Now that you are making progress in therapy, the unconscious mind may be revealing these painful memories because you are better able to psychologically handle them.
Repression of painful memories is a protective mechanism but it is also a costly process, very much like a tourniquet. If you have severely cut your leg, a tourniquet will stop you from bleeding to death. However, if you leave it on too long it will continue to stop the blood flow to the point where your tissues will die, resulting in the need for amputation of the leg. Painful memories can be repressed from the conscious mind but it should be a temporary process. Eventually, when the individual is able to handle these memories, they should be returned to the conscious mind.
The psychotherapeutic process can be painful. Part of why it’s difficult is because one is often forced to deal with aspects of their life that they would rather avoid. The dreams may be an attempt to force your attention on painful memories. Once properly addressed your nightmares may stop.
Historically dream analysis was an integral part of the psychotherapeutic process. It is believed that dreams reveal important information about ourselves. They are produced by the unconscious mind. The unconscious mind knows the truth about ourselves even when we are unwilling or unable to see it for ourselves. Dr. Carl Jung said it best: “The dream shows the inner truth and reality of the patient as it really is: not as I conjecture it to be, and not as he would like it to be, but as it is.”
Your doctor and therapist are correct. It is difficult to verify the validity of dreams. Whether or not the abuse occurred will have little bearing on your current treatment. Either way, your task remains the same. You’ll need to learn how to deal with the emotional triggers relating to the mention of abuse. It is good that you are in treatment. This is an area that your treatment providers can assist you with.
If you want to learn more about the nature of dreams a great place to start is with Carl Jung’s autobiography Memories, Dreams, Reflections. He is considered by many to be the foremost authority on dreams.
I would encourage you to keep track of your dreams and to try and understand their meaning. I wish you continued therapeutic success. Please take care.