Minor problems with result from carelessness on the part of the hypnotist and can usually be prevented by the use of proper technique. They include delayed effects of posthypnotic or uncancelled hypnotic suggestions, misunderstanding by the subject of the suggestions made, and the rare difficulties encoun tered in the termination of hypnosis.

All hypnotic suggestions given during a session that are not intended to affect posthypnotic behavior should be cancelled prior to terminating hypnosis, even if the subject did not appear to accept them. Subjects should be tested in the waking state prior to being dismissed to ensure that these sug gestions have in fact been cancelled. The evidence is that in most cases the subject himself will cancel these suggestions, but it is better not to rely on his implicit understanding that the suggestions were not meant to outlast the ses sion.

Because of the literalness with which most hypnotic subjects react to sug gestions, hypnotists should always avoid the use of idiomatic expressions that, if taken literally, would produce results different from those sought. (For example, a patient told to "Let her hair down" and describe how she really feels about something may actually undo her hair arrangement.) Particular care is required when making suggestions to subjects with limited ability in English who are foreign born, uneducated, or of low intelligence. Precautions must also be taken to ensure that a child patient understands the suggestions clearly. Often very bright children give the hypnotist the illusion that he or she is dealing with a small adult; but even bright children may not understand some words in a suggestion.

Orne (1965a) notes that amateurs are the hypnotists most likely to have difficulty with subjects refusing to terminate a hypnotic state, probably because such a reaction is an ideal passive-aggressive response on the part of a subject who has become angry at the hypnotist. The reason that profes sionals using hypnosis rarely get such reactions is that they fail to reinforce them by getting upset, as does a suddenly frightened and terrified amateur hypnotist.

The possibility of problems with symptom substitution has also been pre viously discussed. It should be noted that this is not properly considered a problem of hypnosis but is a problem of any type of psychotherapy that seeks to directly remove a symptom having a dynamic value to the patient. Some symptoms may have such value; many do not. There is no general agree ment as to what percentage of symptoms fall into either category. The sig nificance of a particular symptom in an individual patient is always a matter of clinical judgment on the part of the therapist.

The remaining psychological problems to be considered here are those reactions that occur either during or immediately after hypnosis and are usually discussed under the rubric of sequelae.

Orne (1965a) finds both qualitative and quantitative differences in the types of hypnotic sequelae seen in the laboratory and in therapeutic settings. If the hypnosis is perceived by the subject as episodic and he has no expectation of permanent change, there are very few sequelae, and any that do occur of a minor nature. This is the case in laboratory research, where the emphasis is impersonal and on the phenomena studied, not the subject, or in dental treatment where effects are also perceived by the subject as temporary.

In experimental work with thousands of "normal college students," in a setting specifically de'ined as experimental and with subjects told that no treatment, however minor, would be given, Orne reports virtually no serious reactions to hypnosis. Anxiety reactions, symptom formations, depressions, or decompensations, which have occasionally been reported in clinical con texts did not occur. The complications that did appear were such minor dis-turbances as an occasional mild and transient headache, drowsiness, nausea, or dizziness. If these complications occur, they typically do so on the first induction and are easily suggested away. The incidence of such reactions was reported by Orne to be from 2% to 3%, which is in close agreement with J. Hilgard's (1965) findings. Orne points out that due to the superficial screening of his subjects and the large numbers of them, it is quite likely that some of them may have had serious psychopathology. Since these results were in an experimental context, they are more likely to reflect the effects of hypnosis per se than the effects of either a therapeutic relationship or therapeutic sug gestion, and these results suggest that hypnosis itself is a safe procedure.

Orne further notes that although minor problems experienced by amateur hypnotists might be concealed, it would be hard for them to hide major problems. Although major problems can occur, they are quite rare, in spite of the incompetence and irresponsibility of the hypnotist. This scarcity of untoward reactions is probably due to the episodic and nontherapeutic nature of the hypnotic session.

The low incidence of serious aversive reactions in experimental work is in contrast to their relatively high incidence in the reports of experienced clini cians. Levitt and Hershman (1961, 1963) surveyed 866 hypnotherapists and found that about 27% of the 301 respondents reported observing major or minor untoward reactions to hypnosis, including anxiety, panic, depression, headache, crying, vomiting, fainting, dizziness, excessive dependency, and eight cases of sexual difficulties and psychotic behavior. Forty-three percent of the psychologists (as compared to 27% of the other respondents) reported these difficulties. J. Hilgard (1974) notes that often the more experienced hypnotists reported the most problems.

Orne (1965a) and Conn(1972) interpret this finding quite differently. Conn believes the prevalence of sequelae reflects an incompetence on the part of the hypnotist, who failed either to dehypnotize subjects properly or to screen them adequately prior to hypnosis. Orne, on the other hand, suggests that only the better-trained therapists adequately observed and recorded sequelae.

Wineburg and Straker (1973) report an acute, self-limiting depersonali zation reaction in a 26-year-old female paraprofessional hospital worker. This woman was used as a demonstration subject in a hospital training course in hypnosis and was given weight reduction suggestions. They believe that the adverse reaction was due to the subject's misconceptions about hypnosis and the fear that it could weaken superego controls over her sexual fantasies. The authors recommend that to prevent reactions such as this, all patients should be observed after hypnotic treatment. Moreover, the patients' beliefs and ex pectations concerning hypnosis should be investigated beforehand, at which time they should be given an explanation of the true nature of hypnosis. This type of reaction, although certainly a risk in hypnotherapy, seems clearly to be the result not of hypnosis but of the patient's fears and inrrapersonal dy namics. It should be preventable by an adequate consideration of these fac tors prior to and during hypnosis. Straker (1973) presents two other cases in which patients developed emotional upsets during a therapeutic induction because of intrapersonal dynamic reasons. In one instance, the induction re sulted in a rapid regression and enhanced transference that flooded the pa tient with childhood memories of early fears and recurrent nightmares. In the other instance, a hypnotic induction took on the significance of a sexual at tack to a 36-year-old female patient because of her previous beliefs about hypnosis. This resonated with earlier rape fantasies, greatly upsetting her. These types of reactions are not different from those obtained in ordinary psychotherapy, but the fostering of regression and transference by hypnosis can make them occur more rapidly and dramatically and give the illusion that they are caused primarily by hypnosis.

Sometimes the unusual nature of the hypnotic state causes even an ex perienced therapist to forget that a hypnotic induction does not cause all of the usual principles of human behavior and interaction to cease to operate. As an illustration, Orne (1965a) cites the case of a dentist whose wife was constantly asking him to hypnotize her for weight reduction suggestions, which he steadfastly refused to do. Instead, he insisted that she see a physician to get diet recommendations. The dentist finally relented and hypnotized his wife, but, instead of making weight loss suggestions, he made the suggestion that she would see her doctor. This suggestion was unsuccessful and resulted In the formation of a minor symptom. The idea of consulting a doctor was unacceptable to this woman in the waking state, and it was equally unacceptable under hypnosis.

Rosen (1960a) cited clinical examples of what he considered to be very serious dangers of hypnosis. These included the development of psychoses and a suicide following the hypnotic removal of phantom limb or low back pain and pruritus. He believes that pain that persists for emotional reasons may be a depressive equivalent and hold a severe depression in check. He is quite critical of weekend hypnotic courses touting hypnosis as an uncov- ering device and believes that neither uncovering techniques nor regressions are safe in the hands of persons ignorant of psychodynamics. Although it is hard to disagree with his contention that no one should treat a patient under hypnosis beyond his competence to treat him while awake, it is equally hard to agree with his view concerning the dangers of hypnosis. The cases he cited are clinical examples and as such cannot establish the causal agency of either the hypnosis or the symptom removal in producing the sequelae claimed. The fact that a psychosis follows hypnosis does not logically demonstrate that II was caused by the hypnosis. Conn (1972), after 30 years of practicing hypnotherapy on over 3,000 patients, denies ever seeing a psychosis pre cipitated by hypnosis. Also, even if such causality could be established, It Hems clear that the cause of adverse reactions reported is less likely to be the hypnosis than the method of psychotherapy. These cases really relate to the issue of symptom substitution, not hypnosis, and the weight of the lit-erature does not support the view that symptom substitution involving new, psychotic, or life threatening symptoms is a high-risk phenomenon.