Recent research has suggested that a person can reprogram scary dreams when awake, by relaxing and thinking of pleasant things they want to dream about instead. They are to deliberately say "Here is what I would like to dream about," and then envisualize flowers, or animals, or beautiful scenes of nature, or whatever is soothing to them. Apparently it works.
It is a bit controversial, because (as iam1butterfly explains well) some therapists feel that dreams reflect the unconscious and therefore should be assessed for what clues they provide into our feelings, and it seems very strange to them that someone would simply ignore all of that information and attempt to reprogram the dream to something pleasant. But for a person with recurring nightmares, this can be a simple and surprisingly effective way to make a change for the better.
Dreams are the contents of the collective unconscious mind and reflect the hopes, wishes, stress factors and anxieties that we experience during our waking state. And, in a sense, they serve as vents... which helps us process deeply seeded emotions, thoughts and ideas. Since your wife's dreams appear to be in the form of nightmares (i.e. "horror and "fear"), I think that your wife might want to analyze what's going on in her life. Is she worried about something or someone? Is there frustration, a struggle or a conflict that's weighing on her? ... because, what's occurring in her waking state might be triggering these dreams.
hi this is not the doctor forums, we are people who have a bit of knowledge and advice, my advice would be to see a doctor and they will refer her to a phyciatrist this will help demolish these dreams