Hypnotically induced dreams can be generated either under Hypnosis or subsequent to it, in which case they are just a specific type of Posthypnotic phenomenon. The subject may be told to have and remember a dream, or the theme of the dream can be suggested with varying degrees of specificity. If the dream is produced under Hypnosis, the subject can be asked to describe it as he is experiencing it. However, since dreams are predominantly visual experiences and one picture will take much more than the proverbial 1,000 words to describe it in all of its details, such simultaneous verbal reports must of necessity be gross abstractions and therefore distortions of the ongoing dream process. What will be reported is a function of the subject's expectations and mental set and what he perceives the experimenter expects.

There is a general agreement that Hypnotic and Posthypnotic dreams, especially the former, tend to differ from naturally occurring nocturnal dreams. Specifically, they tend to be shorter, more verbal, less bizarre, and contain less symbolism. Barber (1962) says that they are often difficult to distinguish from simple verbal associations to the dream topic suggested. They resemble non-rem nocturnal dreams, which are often described by subjects in dream studies as thinking rather than dreaming. In a review of the literature on Hypnotic and Posthypnotic dreams Barber concluded that:

Hypnotic dreams typically contain very little evidence of the operation of the dream work; that is, they are not distorted or symbolic representations and good Hypnotic subjects often describe their imaginative products as dreams in order to comply with the expectations of the experimenter.
When Hypnotic dreams are reported involving predominantly pictorial images and a high degree of symbolic material, they do not differ significantly from reports of some nonhypnotized subjects instructed to make up symbolic dreamlike material.
Some subjects who report dreaming about the Hypnotic situation the following night in response to a posthypnotic suggestions might have done so without the suggestion since the interesting experimental situation could have functioned as an ordinary day residue.
Evidence was found in some studies that both Hypnotic and control subjects given posthypnotic suggestions to dream at night did not sleep normally and actually awakened during the night and purposely created dreams that they were motivated to produce.
The notion that subjects are better able to interpret dreams under Hypnosis in the absence of the familiarity with psychology has not been demonstrated.

Barrett (1979), on the other hand, in comparing the Hypnotic dreams of 16 medium-to high-susceptibility male and female subjects with the non Hypnotic nocturnal dreams and daydreams of the same subjects, found a clear relationship between depth of trance and the characteristics of Hypnotic dreams. She found that the Hypnotic dreams of deeply Hypnotized subjects were quite similar to nocturnal dreams and concluded that it was therefore appropriate to use them in therapy as though they were nocturnal dreams; but for medium-susceptibility subjects, content difference were found between Hypnotic and nocturnal dreams.

Dave (1979) reports a study demonstrating the value of hypnotically induced dreams, not in psychotherapy but to aid in the development of creative solutions to problems of an academic, vocational, avocational, or personal nature about which subjects were at an impasse prior to dream manipulation.

Six out of eight subjects in the Hypnotic dream group were successful in solving their problem, as compared to one out of eight in a rational-cognitive treatment group and none out of eight in a control group given only a personal interview.

Torda (1975) used posthypnotic suggestions creating emotional states to study the effects of these emotions on naturally occurring nocturnal dreams in subjects sleeping in her laboratory. Subjects were awakened after each REM period with instructions to verbalize their dreams. The effectiveness of the posthypnotic suggestions in generating the emotional states was confirmed by various physiological measures made on the subjects. This study, although more typical of ordinary dream research than research on Hypnotically induced dreams, suggests that future Hypnotic dream studies ought to adopt the methodology of monitoring sleep continuously with an EEG and waking subjects for dream reports after each REM period. In addition to answering Barbers questions concerning the reality of the reported dream experience, EEG research is capable of producing a greater yield of dreams and hence could pick up dreams compliant with posthypnotic suggestions that were forgotten in spite of suggestions to remember them. Most research on posthypnotic dreams relies on the memory of the subjects the following morning

----Five subjects were given suggestions to make an effort not to dream, eight were given suggestions to facilitate dreaming, and four were given a posthyhpnotic suggestion unrelated to sleep or dreaming. Suggestions to inhibit or facilitate dreaming had a marked effect in the expected direction, based on subjective reports of the subjects the following morning. In addition EEG tracings made on the subjects throughout the night showed that two of the five dream-inhibition subjects had a dramatic reduction in REM sleep. This reduction demonstrated that there was more than the demand characteristics of the experimental situation involved in the subjective effects. No increase in REM sleep was found for the dream <ETH>facilitation subjects, and subjects in the three groups did not differ significantly in NREM sleep.