Fifteen studies were included in the review. Two studies (n=73) assessed learning problems, 2 (n=105) assessed physiological processes, 3 (n=110) addressed general medical problems, 3 (n=93) chemotherapy distress, and 5 (n=181) acute pain.
Learning problems.
Test anxiety: in one study, the self-hypnosis group achieved significantly greater reductions on the questionnaire measure of test anxiety at post-treatment and at 6 months, compared with controls.
Learning disabilities: one study found no significant differences between the intervention and control groups in gains on measures of academic achievement or self esteem.
Basic physiological processes.
Temperature regulation: one study found that all three intervention groups were able to produce significant changes in skin temperature, but there were no significant differences among the groups in amount of warming or cooling.
Immune functioning: one study found no significant pre- to post- intervention differences among the three experimental groups on IgG levels, although the relaxation plus suggestion group (but not the self-hypnosis or attention control groups) showed a significant increase from time 2 to time 3 for IgA levels.
General medical problems.
Cystic fibrosis: one study showed that, compared with the control group, the treatment group achieved significantly greater improvements in lung function, self-esteem, state anxiety, and health and locus of control. Enuresis: one study reported that by the end of treatment, the number of wet nights per week for the induction-plus-suggestion and suggestion-only groups had decreased significantly relative to the other conditions. Across a 6-month period, all three treatments produced significantly greater reductions in wet nights than the control condition, indicating that suggestions for dry nights in or out of the context of hypnosis may be useful. Another study found that across the 3-month treatment period, the proportion of positive responders did not differ between the two groups, but at 6 months' post-treatment follow-up, there was a significant difference between the two treatments; this was accounted for by the substantial number of children in the medication (imipramine) group who had relapsed without medication.
Nausea and emesis from chemotherapy.
Compared with the control condition, one study reported significantly shorter duration of vomiting in the hypnosis condition (imagination-focused hypnosis), and significantly shorter duration of nausea in both the hypnosis and distraction/relaxation conditions. A second study found that both interventions (imagination-focused and attention diversion) were found to produce significant reductions in nausea and vomiting, but there was no difference between the two treatments in the amount of relief obtained. A third study found that following the intervention (self-hypnosis with imagination and control of anti-emetic medication, plus additional medication as needed), episodes of nausea and vomiting were equivalent between the two conditions, but the controls used significantly more anti-emetics than the children in the hypnosis group.
Acute pain.
Experimental pain: in one study, children in the hypnosis condition experienced significantly more pain reduction than the controls (no intervention). Invasive medical procedures, e.g. bone marrow aspiration: one study found that for both self-hypnosis and attention-control groups, self-reported pain decreased significantly whereas observer pain did not. However, there was no difference between hypnosis and the attention-control condition in pain or fear reduction.
Another study found that older children in the hypnosis and distraction conditions achieved significantly greater reductions in observer-rated pain and anxiety than the control (standard medical care) group. Among younger children, those in the hypnosis condition achieved significantly greater reductions in observer-rated distress than those in the other conditions. Self-report measures of pain and anxiety suggested neither intervention was more successful than standard medical practice. A fourth study found that hypnosis was significantly more effective than distraction in reducing pain and anxiety during bone marrow aspiration, and only hypnosis significantly reduced both pain and anxiety during lumbar punctures. A final study found that for self-reported pain and anxiety, highly suggestible children in the hypnosis treatment reported significantly less pain and anxiety following interventions than did those in the distraction condition, or less suggestible children in both conditions. The parents' reports of pain reduction were similar.