Effects of Hypnotic, Placebo, and Salicylic Acid Treaments on Wart Regression NICHOLAS P. SPANOS, VICTORIA WILLIAMS, AND MAXWELL I. GWYNN Subjects with warts on their hands and/or feet were randomly assigned to a hypnotic suggestion, topical salicylic acid, placebo, or no treatment control condition. Subjects in the three treated groups developed equivalent expectations of treatment success. Nevertheless, at the six-week follow-up interval only the hypnotic subjects had lost significantly more warts than the no treatment controls. Theoretical implications are discussed.
INTRODUCTION
Human warts are benign, infectious tumors of the skin that are produced by members of the papillomaviruses genus (1). Numerous uncontrolled clinical reports (cf. Ref. 2) have long implicated suggestive factors (broadly defined) in the remission of warts, and three experiments now indicate that subjects administered imagery-based suggestions exhibit significantly greater wart regression than untreated controls (3, 4]. In one of these experiments (Ref. 3, Experiment 2) imagery-based suggestions given without a prior hypnotic induction procedure were as effective as imagery-based hypnotic suggestions at inducing wart regression. Both the hypnotic and nonhypnotic suggestion treatments were more effective in this regard than a no treatment control procedure. In another experiment (Ref. 3, Experiment 1) hypnotic suggestions were
From the Department of Psychology, Carleton University, Ottawa, Canada. Address reprint requests to: Nicholas P. Spanos, Department of Psychology, Carleton University, Ottawa K14 5B6, Canada. Received April 14, 1989; revision received October 12, 1989.
Psychosomatic Medicine 52:109-114 (1990) 0033-3174/90/5201-0109S02 00/0 Copyright 1990 by the American Psychosomatic Society
more effective at inducing wart regression than either a placebo treatment or a no treatment control procedure. Subjects in the placebo and control conditions did not differ significantly in degree of wart regression. The latter finding was somewhat surprising because an early study (5) reported significantly greater wart regression in placebo subjects than in no treatment controls. The effective components in suggestive procedures have yet to be clearly delineated. For example, one hypothesis (6) holds that expectations of treatment success constitute the direct psychological cause of wart regression in all suggestive treatments. According to this hypothesis imagery strategies play no special role in wart regression beyond enhancing subjects' expectations of treatment success. Therefore, imagery-based suggestions and placebo treatments that generate equivalent expectations of treatment success should yield similar outcomes. Unfortunately, Spanos et al. (3) did not assess the efficacy expectations of the hypnotic or placebo subjects in their first experiment and, therefore, were unable to test this hypothesis. Several investigators (7,8) have hypothesized that suggestion-induced imagery is important for wart regression above and 109
SPANOS et al.
beyond its role in enhancing efficacy expectations. Along these lines it has been found (3) that the vividness with which subjects rated their suggested imagery correlated significantly with wart regression, while efficacy expectations failed to correlate significantly with wart regression. The present study compared the effects of hypnotic suggestion and placebo treatments while assessing efficacy expectations for subjects in each treatment. When adults are treated with suggestion it usually takes from several days to several weeks before evidence of wart regression becomes manifest. A lack of close observation during this period is common, and raises the possibility that suggestion-induced wart regression may involve surreptitious self-medication with nonprescription salicylic acid compounds that are available in most drug stores. Some subjects, wishing both to eliminate their warts and to please the experimenter, may resort to surreptitious self-medication when their warts do not clear up in what they consider to be a reasonable period of time. The present study compared the pattern of wart loss found in subjects administered hypnotic suggestions with the patterns found in subjects who self-applied a nonprescription salicylic acid treatment, subjects who self-applied a placebo treatment, and no treatment control subjects. METHODS
Subjects Fifteen females and 25 males (ages 18-35 years) with warts on at least one hand or foot were recruited through posters and from newspaper advertisements. Subjects were asked to abstain from any other wart treatment for the duration of the study, and were either paid 20 dollars or given course credit for their participation.
110
Procedure Subjects were randomly assigned to a hypnotic suggestion, topical salicylic acid, topical placebo, or no treatment control condition with an equal number of subjects (N = 10) in each condition. There were 6 males and 4 females in each of the acid, placebo, and control groups, while the hypnosis group contained 7 males and 3 females. Each subject was seen individually by a technician who counted the warts on each of their hands and/or feet. Hypnotic, acid, and placebo subjects were administered their respective treatments by 1he same female therapist and scheduled to return in six weeks for followup evaluation. Control subjects were informed that they were on a waiting list and were asked to return in six weeks to receive treatment. Immediately after the administration of their treatment, subjects in the hypnotic, acid, and placebo conditions rated their expectations of treatment success on the following item taken from Ref. 3: "How effective do you think this treatment will be at removing your warts?" Alternatives ranged from "not at all effective" (scored zero) to "extremely effective" (scored 10). Subjects in the three treated groups were then instructed in how to apply their respective treatment once every day, and informed that their treatment was likely to be associated with the sensations of warmth, tingling, shrinking, and prickling in the skin around their warts. They were instructed to rate in a diary the extent to which they experienced each of these sensations during their daily treatment self-administration on a scale taken from (3). Each sensation was rated on a seven-point intensity subscale, and the four subscale scores were summed to yield a single intensity of suggested sensations score for each subject. At the end of the six-week follow-up period all subjects had their warts recounted by a technician who was blind to their treatment. Next, subjects were tested in groups of 2 to 5 individuals for hypnotizability using the Carleton University Responsiveness to Suggestion Scale (CURSS) (Ref. 9). This scale assessed both overt responsiveness to hypnotic suggestions (CURSS:O) and subjective responsiveness to suggestions (CURSS:S).
Hypnotic Treatment After being comfortably seated and asked to close their eyes, subjects were orally administered a 10minute hypnotic induction procedure modified from
Psychosomatic Medicine 52:109-114 (1990)
TREATMENT OF WARTS Ref. 10. The induction included interrelated suggestions for sleep, drowsiness, and entering hypnosis. Following the induction procedure, and without a break in continuity, subjects were given a suggestion for wart regression that was 2 minutes in duration. The suggestion was taken verbatim from Ref. 3 and informed subjects that the skin around their warts was beginning to tingle and grow warm, and then asked subjects to vividly imagine their warts shrinking and dissolving away. Following a 30-second break the suggestion was repeated. For subjects with warts on more than one limb the complete suggestion procedure was repeated for each wart-infected limb. Subjects were then "awakened," rated their expectancies, and were instructed to practice their wart regression imagery once each day. They were asked to spend approximately 1 minute per wartinfected limb imagining their warts shrinking and disappearing. Finally, they were instructed in the use of their daily wart diary and scheduled for their 6-week follow-up session.
Salicylic Acid Treatment Subjects in this treatment were informed that they would be treated with a new, topically applied wart-killing compound called "Dermacyl." They were further informed that preliminary tests indicated that the compound was highly effective. The experimenter applied the compound to subjects' warts and instructed subjects as to the correct method of application. Subjects were then instructed in the use of their daily diary and scheduled for their follow-up appointment. The "Dermacyl" administered to these subjects was a nonprescription salicylic acid compound marketed under the trade name "Compound W." The instructions given to subjects were taken verbatim from those supplied with the compound by the manufacturer. The two week limit on application of the compound was also taken from the manufacturer's instructions.
Placebo Treatment The treatment given to subjects in this group was the same as that given to those in the salicylic acid condition except that the "Dermacyl" given to the placebo subjects contained no medicinal properties.
Psychosomatic Medicine 52:109-114 (1990)
No Treatment Control After having their warts counted these subjects were informed that they would receive treatment in six weeks, and were then scheduled to return to the laboratory at that time These subjects were not instructed to count their warts or keep a daily diary.
RESULTS
Age, Wart Duration, and Warts at Baseline Separate one-way analyses of variance (ANOVAs) compared the ages (in years) of subjects in the four conditions and their estimates of wart duration. Neither analysis approached significance. A 4 X 2 (conditions x sex) ANOVA indicated that females (M = 3.07, SD = 2.05) had significantly more warts at baseline than did males, (M = 1.96, SD = 1.24; F (1,32) = 4.55; p < 0.05). However, there were no significant differences between conditions in warts at baseline, and the sex X x conditions interaction was also nonsignificant.
Treatment Effects Wart loss. The majority of subjects in this experiment (77.5%, N = 31) had three or fewer warts at baseline. Consequently we employed both a continuous index of wart loss (the number of warts at followup minus the number at baseline) and a dichotomous index (no warts lost/one or more warts lost). A 4 X 2 (conditions X sex) ANOVA on the number of warts lost indicated a significant main effect for conditions, F (3,32) 5.13, p > 0.01. Post hoc analysis (Newman-Keuls) indicated that the hypnotic 111
SPANOS et al.
subjects lost significantly more warts than subjects in the remaining three conditions. No other comparisons attained significance, and the relevant means are given in Table 1. Neither the main effect for sex nor the interaction was significant. Table 2 shows the number of subjects in each condition who lost one or more warts or who did not lost warts. The four conditions differed significantly in this regard, (3) = 11.20, p < 0.05. Further analysis indicated that the acid, placebo, and control conditions failed to differ significantly from one another in the number of subjects who lost warts x2 (12) = 4.03, p > 0.10. Therefore, these three groups were combined and compared to the hypnotic condition. Hypnotic subjects were significantly more likely to lose warts than were subjects In the combined conditions, x2 (1) = 8.71, p < 0.01. Expectancy and suggested sensation diary ratings. There were no significant differences between treatments in the extent to which subjects expected their treatment to be effective, F (2,27) < 1. Subjects in the three treated groups rated the intensity of the sensations they TABLE 1.
were Instructed to look for in their daily diaries. We restricted our analysis of this dimension to subjects' first day diary entries because complete data were available from all subjects at this point. Furthermore, none of the subjects had noted changes in their warts at this point and, therefore, they could not infer the intensity of their sensations from loss or change in their warts. Subjects in the three treatments differed significantly in their intensity ratings of the suggested sensations, F (2,27) = 17.22, p > 0.01. Post hoc tests indicated that hypnotic subjects rated their suggested sensations as significantly more intense than did subjects In the acid or placebo conditions. No other differences were significant. Hypnotizability. There were no significant differences on the CURSS:O index. However, significant differences were found on the CURSS:S, F (3,36) 4.01, p < 0.05. Post hoc tests indicated that hypnotic subjects (M = 11.20, SD = 5.90) attained significantly higher CURSS:S scores than controls (M = 4.80, SD = 3.88). The CURSS:S scores of Acid, M = 5.10, SD = 4.28, and Placebo, M = 4.80, SD = 2.62,
Means for Number of Warts at Baseline and Number of Warts Lost for Subjects in Each Condition Hypr1OSIS
Baseline warts Wart loss
Acid
Plaicebo
C o i Urol
M
SD
M
SD
M
SD
M
SD
2.40" 1.30"
1.35 1.57
2.70a 0"
1.70 0
2.9Oa -0.20b
2.23 1.23
1.50* O.3O6
0.97 0.48
Within-row means sharing a common superscript letter fail to differ significantly at alpha = 0.05.
TABLE 2.
Number of Subjects in Each Condition Who Lost One or More Weirts or Who Did Not Lose Warts
Lost warts No wart loss
112
Hypnosis
Acid
Placebo
Control
6 4
0 10
1 9
3 7
Psychosomatic Medicine 52:109-114 (1990)
TREATMENT OF WARTS TABLE 3. Means for Expectancy of Treatment Success Ratings and Intensity of Suggested Sensations Ratings for Subjects in the Hypnosis, Acid and Placebo Treatments Acid
Hypnosis
Expectancy Sensation intensity
Placebo
M
SD
M
SD
M
SD
6.4a 18.30a
1.58 7.48
6.6a 6.90"
1.78 2.51
6.23 7.70 "
1.62 2.87
Within-row means sharing a common superscript letter fail to differ significantly at alpha = 0.05.
Hypnotic subjects attained significantly higher CURSS:S scores than did control subjects. Nevertheless, it is unlikely that between group differences in hypnotizabillty accounted for the group differences in wart regression. Two previous experiDISCUSSION ments (3) that used the CURSS found that The hypnotic suggestion treatment pro- hypnotizability failed to predict wart loss duced significantly more wart regression in either hypnotic suggestion, nonhypthan the acid or placebo treatment or than notic suggestion, or placebo treatments, no treatment. These results replicate and and even in the present study the hypextend those of earlier controlled experi- notic treatment failed to differ from either ments (3, 4), and support the hypothesis the real or placebo treatment on CURSS:S that psychological factors can substan- scores, and none of the treatments diftially influence the course of at least some fered significantly on CURSS:O scores. virally produced disorders (e.g., Ref. 11). Our finding and earlier findings that hypThe superiority of the hypnotic treatment notic subjects reported more intense sugover the acid treatment provides strong gested sensations than placebo subjects is evidence against the hypothesis that sug- consistent with the hypothesis that vivid gestion-induced wart regression can be suggested imagery facilitates wart loss (7, explained away in terms of surreptitious 8). self-medicating. An alternative hypothesis emphasizes There were no significant differences that only our hypnotic suggestion treatbetween conditions in subjects' ages or In ment encouraged subjects to see themtheir estimates of wart duration. Further- selves as developing cognitive control more, subjects in the three treated groups over their own wart regression. This hyfailed to differ in their ratings of expected pothesis suggests that subjects' subjective treatment success. The latter findings, sense of cognitive Involvement in and along with an earlier failure to find a control over treatment outcome (as opsignificant correlation between suggested posed to the vividness of their suggested wart loss and expectancy (3), contradicts imagery) may have been the Important the hypothesis that expectation of treat- psychological factor in wart regression, it ment success is the most important vari- would be of Interest in a future study to able in psychologically induced wart manipulate subjects' sense of cognitive regression. involvement in their treatment independsubjects failed to differ significantly from each other or from those of the hypnotic and control groups.
Psychosomatic Medicine 52:109-114 (1990)
113
SPANOS et al. ently of suggested imagery in order to assess the relative contributions of these variables to wart regression.
This research was supported by a grant to the N.P.S. from the Natural Sciences and Engineering Research Council of Canada.
REFERENCES 1. White DO, Fenner F: Medical Virology. New York, Academic Press 1986 2. Johnson RFQ: Hypnosis, suggestion, and dermatological changes: A consideration of the production and diminution of dermatological entities. In NP Spanos JF Chaves (Eds), Hypnosis: Cognitive-behavioral perspectives pp 297-312. Buffalo, NY, Prometheus 1989 3. Spanos NP, Stenstrom RJ, Johnston JC: Hypnosis, placebo and suggestion In the treatment of warts. Psychosom Med 50:245-260 1988 4. Surman OS, Gottlieb SK, Hackett TP, Silverberg EL: Hypnosis in the treatment of warts. Arch Gen Psychiatry 28:439-441 1973 5. Memmesheimer AM, Eisenlohr E: Unterschungen uber die suggestive behandlung der warzen. Dermato] Z 62:63-68 1931 6. Kirsch I: Response expectancy as a determinant of experience and behavior. Am Psychol 40:1189-1202 1985 7. Achterberg J: Imagery in Healing. Boston, New Sciences Library 1985 8. Barber TX: Changing "unchangeable" bodily processes by (hypnotic) suggestions: A new look at hypnosis, cognitions, imagining, and the mind-body problem. In AA Sheikh (ed), Imagination and Healing. New York, Baywood, 1984, pp 69-128 9. Spanos NP, Radtke HL, Hodgins DC, Stam HJ, Bertrand LD: The Carleton University Responsiveness to Suggestion Scale: Normative data and psychometric properties. Psychol Rep 53:523-535,1983 10. Barber TX:. Hypnosis: A Scientific Approach. New York, Van Nostrand Reinhold, 1969 11. Longo DJ, Clum GA, Yaeger NJ: Psychosocial treatment for recurrent genital herpes. J Consult Clin Psychol 56:61-66 1988
114
Psychosomatic Medicine 52:109-114 (1990)
INTRODUCTION
Human warts are benign, infectious tumors of the skin that are produced by members of the papillomaviruses genus (1). Numerous uncontrolled clinical reports (cf. Ref. 2) have long implicated suggestive factors (broadly defined) in the remission of warts, and three experiments now indicate that subjects administered imagery-based suggestions exhibit significantly greater wart regression than untreated controls (3, 4]. In one of these experiments (Ref. 3, Experiment 2) imagery-based suggestions given without a prior hypnotic induction procedure were as effective as imagery-based hypnotic suggestions at inducing wart regression. Both the hypnotic and nonhypnotic suggestion treatments were more effective in this regard than a no treatment control procedure. In another experiment (Ref. 3, Experiment 1) hypnotic suggestions were
From the Department of Psychology, Carleton University, Ottawa, Canada. Address reprint requests to: Nicholas P. Spanos, Department of Psychology, Carleton University, Ottawa K14 5B6, Canada. Received April 14, 1989; revision received October 12, 1989.
Psychosomatic Medicine 52:109-114 (1990) 0033-3174/90/5201-0109S02 00/0 Copyright 1990 by the American Psychosomatic Society
more effective at inducing wart regression than either a placebo treatment or a no treatment control procedure. Subjects in the placebo and control conditions did not differ significantly in degree of wart regression. The latter finding was somewhat surprising because an early study (5) reported significantly greater wart regression in placebo subjects than in no treatment controls. The effective components in suggestive procedures have yet to be clearly delineated. For example, one hypothesis (6) holds that expectations of treatment success constitute the direct psychological cause of wart regression in all suggestive treatments. According to this hypothesis imagery strategies play no special role in wart regression beyond enhancing subjects' expectations of treatment success. Therefore, imagery-based suggestions and placebo treatments that generate equivalent expectations of treatment success should yield similar outcomes. Unfortunately, Spanos et al. (3) did not assess the efficacy expectations of the hypnotic or placebo subjects in their first experiment and, therefore, were unable to test this hypothesis. Several investigators (7,8) have hypothesized that suggestion-induced imagery is important for wart regression above and 109
SPANOS et al.
beyond its role in enhancing efficacy expectations. Along these lines it has been found (3) that the vividness with which subjects rated their suggested imagery correlated significantly with wart regression, while efficacy expectations failed to correlate significantly with wart regression. The present study compared the effects of hypnotic suggestion and placebo treatments while assessing efficacy expectations for subjects in each treatment. When adults are treated with suggestion it usually takes from several days to several weeks before evidence of wart regression becomes manifest. A lack of close observation during this period is common, and raises the possibility that suggestion-induced wart regression may involve surreptitious self-medication with nonprescription salicylic acid compounds that are available in most drug stores. Some subjects, wishing both to eliminate their warts and to please the experimenter, may resort to surreptitious self-medication when their warts do not clear up in what they consider to be a reasonable period of time. The present study compared the pattern of wart loss found in subjects administered hypnotic suggestions with the patterns found in subjects who self-applied a nonprescription salicylic acid treatment, subjects who self-applied a placebo treatment, and no treatment control subjects. METHODS
Subjects Fifteen females and 25 males (ages 18-35 years) with warts on at least one hand or foot were recruited through posters and from newspaper advertisements. Subjects were asked to abstain from any other wart treatment for the duration of the study, and were either paid 20 dollars or given course credit for their participation.
110
Procedure Subjects were randomly assigned to a hypnotic suggestion, topical salicylic acid, topical placebo, or no treatment control condition with an equal number of subjects (N = 10) in each condition. There were 6 males and 4 females in each of the acid, placebo, and control groups, while the hypnosis group contained 7 males and 3 females. Each subject was seen individually by a technician who counted the warts on each of their hands and/or feet. Hypnotic, acid, and placebo subjects were administered their respective treatments by 1he same female therapist and scheduled to return in six weeks for followup evaluation. Control subjects were informed that they were on a waiting list and were asked to return in six weeks to receive treatment. Immediately after the administration of their treatment, subjects in the hypnotic, acid, and placebo conditions rated their expectations of treatment success on the following item taken from Ref. 3: "How effective do you think this treatment will be at removing your warts?" Alternatives ranged from "not at all effective" (scored zero) to "extremely effective" (scored 10). Subjects in the three treated groups were then instructed in how to apply their respective treatment once every day, and informed that their treatment was likely to be associated with the sensations of warmth, tingling, shrinking, and prickling in the skin around their warts. They were instructed to rate in a diary the extent to which they experienced each of these sensations during their daily treatment self-administration on a scale taken from (3). Each sensation was rated on a seven-point intensity subscale, and the four subscale scores were summed to yield a single intensity of suggested sensations score for each subject. At the end of the six-week follow-up period all subjects had their warts recounted by a technician who was blind to their treatment. Next, subjects were tested in groups of 2 to 5 individuals for hypnotizability using the Carleton University Responsiveness to Suggestion Scale (CURSS) (Ref. 9). This scale assessed both overt responsiveness to hypnotic suggestions (CURSS:O) and subjective responsiveness to suggestions (CURSS:S).
Hypnotic Treatment After being comfortably seated and asked to close their eyes, subjects were orally administered a 10minute hypnotic induction procedure modified from
Psychosomatic Medicine 52:109-114 (1990)
TREATMENT OF WARTS Ref. 10. The induction included interrelated suggestions for sleep, drowsiness, and entering hypnosis. Following the induction procedure, and without a break in continuity, subjects were given a suggestion for wart regression that was 2 minutes in duration. The suggestion was taken verbatim from Ref. 3 and informed subjects that the skin around their warts was beginning to tingle and grow warm, and then asked subjects to vividly imagine their warts shrinking and dissolving away. Following a 30-second break the suggestion was repeated. For subjects with warts on more than one limb the complete suggestion procedure was repeated for each wart-infected limb. Subjects were then "awakened," rated their expectancies, and were instructed to practice their wart regression imagery once each day. They were asked to spend approximately 1 minute per wartinfected limb imagining their warts shrinking and disappearing. Finally, they were instructed in the use of their daily wart diary and scheduled for their 6-week follow-up session.
Salicylic Acid Treatment Subjects in this treatment were informed that they would be treated with a new, topically applied wart-killing compound called "Dermacyl." They were further informed that preliminary tests indicated that the compound was highly effective. The experimenter applied the compound to subjects' warts and instructed subjects as to the correct method of application. Subjects were then instructed in the use of their daily diary and scheduled for their follow-up appointment. The "Dermacyl" administered to these subjects was a nonprescription salicylic acid compound marketed under the trade name "Compound W." The instructions given to subjects were taken verbatim from those supplied with the compound by the manufacturer. The two week limit on application of the compound was also taken from the manufacturer's instructions.
Placebo Treatment The treatment given to subjects in this group was the same as that given to those in the salicylic acid condition except that the "Dermacyl" given to the placebo subjects contained no medicinal properties.
Psychosomatic Medicine 52:109-114 (1990)
No Treatment Control After having their warts counted these subjects were informed that they would receive treatment in six weeks, and were then scheduled to return to the laboratory at that time These subjects were not instructed to count their warts or keep a daily diary.
RESULTS
Age, Wart Duration, and Warts at Baseline Separate one-way analyses of variance (ANOVAs) compared the ages (in years) of subjects in the four conditions and their estimates of wart duration. Neither analysis approached significance. A 4 X 2 (conditions x sex) ANOVA indicated that females (M = 3.07, SD = 2.05) had significantly more warts at baseline than did males, (M = 1.96, SD = 1.24; F (1,32) = 4.55; p < 0.05). However, there were no significant differences between conditions in warts at baseline, and the sex X x conditions interaction was also nonsignificant.
Treatment Effects Wart loss. The majority of subjects in this experiment (77.5%, N = 31) had three or fewer warts at baseline. Consequently we employed both a continuous index of wart loss (the number of warts at followup minus the number at baseline) and a dichotomous index (no warts lost/one or more warts lost). A 4 X 2 (conditions X sex) ANOVA on the number of warts lost indicated a significant main effect for conditions, F (3,32) 5.13, p > 0.01. Post hoc analysis (Newman-Keuls) indicated that the hypnotic 111
SPANOS et al.
subjects lost significantly more warts than subjects in the remaining three conditions. No other comparisons attained significance, and the relevant means are given in Table 1. Neither the main effect for sex nor the interaction was significant. Table 2 shows the number of subjects in each condition who lost one or more warts or who did not lost warts. The four conditions differed significantly in this regard, (3) = 11.20, p < 0.05. Further analysis indicated that the acid, placebo, and control conditions failed to differ significantly from one another in the number of subjects who lost warts x2 (12) = 4.03, p > 0.10. Therefore, these three groups were combined and compared to the hypnotic condition. Hypnotic subjects were significantly more likely to lose warts than were subjects In the combined conditions, x2 (1) = 8.71, p < 0.01. Expectancy and suggested sensation diary ratings. There were no significant differences between treatments in the extent to which subjects expected their treatment to be effective, F (2,27) < 1. Subjects in the three treated groups rated the intensity of the sensations they TABLE 1.
were Instructed to look for in their daily diaries. We restricted our analysis of this dimension to subjects' first day diary entries because complete data were available from all subjects at this point. Furthermore, none of the subjects had noted changes in their warts at this point and, therefore, they could not infer the intensity of their sensations from loss or change in their warts. Subjects in the three treatments differed significantly in their intensity ratings of the suggested sensations, F (2,27) = 17.22, p > 0.01. Post hoc tests indicated that hypnotic subjects rated their suggested sensations as significantly more intense than did subjects In the acid or placebo conditions. No other differences were significant. Hypnotizability. There were no significant differences on the CURSS:O index. However, significant differences were found on the CURSS:S, F (3,36) 4.01, p < 0.05. Post hoc tests indicated that hypnotic subjects (M = 11.20, SD = 5.90) attained significantly higher CURSS:S scores than controls (M = 4.80, SD = 3.88). The CURSS:S scores of Acid, M = 5.10, SD = 4.28, and Placebo, M = 4.80, SD = 2.62,
Means for Number of Warts at Baseline and Number of Warts Lost for Subjects in Each Condition Hypr1OSIS
Baseline warts Wart loss
Acid
Plaicebo
C o i Urol
M
SD
M
SD
M
SD
M
SD
2.40" 1.30"
1.35 1.57
2.70a 0"
1.70 0
2.9Oa -0.20b
2.23 1.23
1.50* O.3O6
0.97 0.48
Within-row means sharing a common superscript letter fail to differ significantly at alpha = 0.05.
TABLE 2.
Number of Subjects in Each Condition Who Lost One or More Weirts or Who Did Not Lose Warts
Lost warts No wart loss
112
Hypnosis
Acid
Placebo
Control
6 4
0 10
1 9
3 7
Psychosomatic Medicine 52:109-114 (1990)
TREATMENT OF WARTS TABLE 3. Means for Expectancy of Treatment Success Ratings and Intensity of Suggested Sensations Ratings for Subjects in the Hypnosis, Acid and Placebo Treatments Acid
Hypnosis
Expectancy Sensation intensity
Placebo
M
SD
M
SD
M
SD
6.4a 18.30a
1.58 7.48
6.6a 6.90"
1.78 2.51
6.23 7.70 "
1.62 2.87
Within-row means sharing a common superscript letter fail to differ significantly at alpha = 0.05.
Hypnotic subjects attained significantly higher CURSS:S scores than did control subjects. Nevertheless, it is unlikely that between group differences in hypnotizabillty accounted for the group differences in wart regression. Two previous experiDISCUSSION ments (3) that used the CURSS found that The hypnotic suggestion treatment pro- hypnotizability failed to predict wart loss duced significantly more wart regression in either hypnotic suggestion, nonhypthan the acid or placebo treatment or than notic suggestion, or placebo treatments, no treatment. These results replicate and and even in the present study the hypextend those of earlier controlled experi- notic treatment failed to differ from either ments (3, 4), and support the hypothesis the real or placebo treatment on CURSS:S that psychological factors can substan- scores, and none of the treatments diftially influence the course of at least some fered significantly on CURSS:O scores. virally produced disorders (e.g., Ref. 11). Our finding and earlier findings that hypThe superiority of the hypnotic treatment notic subjects reported more intense sugover the acid treatment provides strong gested sensations than placebo subjects is evidence against the hypothesis that sug- consistent with the hypothesis that vivid gestion-induced wart regression can be suggested imagery facilitates wart loss (7, explained away in terms of surreptitious 8). self-medicating. An alternative hypothesis emphasizes There were no significant differences that only our hypnotic suggestion treatbetween conditions in subjects' ages or In ment encouraged subjects to see themtheir estimates of wart duration. Further- selves as developing cognitive control more, subjects in the three treated groups over their own wart regression. This hyfailed to differ in their ratings of expected pothesis suggests that subjects' subjective treatment success. The latter findings, sense of cognitive Involvement in and along with an earlier failure to find a control over treatment outcome (as opsignificant correlation between suggested posed to the vividness of their suggested wart loss and expectancy (3), contradicts imagery) may have been the Important the hypothesis that expectation of treat- psychological factor in wart regression, it ment success is the most important vari- would be of Interest in a future study to able in psychologically induced wart manipulate subjects' sense of cognitive regression. involvement in their treatment independsubjects failed to differ significantly from each other or from those of the hypnotic and control groups.
Psychosomatic Medicine 52:109-114 (1990)
113
SPANOS et al. ently of suggested imagery in order to assess the relative contributions of these variables to wart regression.
This research was supported by a grant to the N.P.S. from the Natural Sciences and Engineering Research Council of Canada.
REFERENCES 1. White DO, Fenner F: Medical Virology. New York, Academic Press 1986 2. Johnson RFQ: Hypnosis, suggestion, and dermatological changes: A consideration of the production and diminution of dermatological entities. In NP Spanos JF Chaves (Eds), Hypnosis: Cognitive-behavioral perspectives pp 297-312. Buffalo, NY, Prometheus 1989 3. Spanos NP, Stenstrom RJ, Johnston JC: Hypnosis, placebo and suggestion In the treatment of warts. Psychosom Med 50:245-260 1988 4. Surman OS, Gottlieb SK, Hackett TP, Silverberg EL: Hypnosis in the treatment of warts. Arch Gen Psychiatry 28:439-441 1973 5. Memmesheimer AM, Eisenlohr E: Unterschungen uber die suggestive behandlung der warzen. Dermato] Z 62:63-68 1931 6. Kirsch I: Response expectancy as a determinant of experience and behavior. Am Psychol 40:1189-1202 1985 7. Achterberg J: Imagery in Healing. Boston, New Sciences Library 1985 8. Barber TX: Changing "unchangeable" bodily processes by (hypnotic) suggestions: A new look at hypnosis, cognitions, imagining, and the mind-body problem. In AA Sheikh (ed), Imagination and Healing. New York, Baywood, 1984, pp 69-128 9. Spanos NP, Radtke HL, Hodgins DC, Stam HJ, Bertrand LD: The Carleton University Responsiveness to Suggestion Scale: Normative data and psychometric properties. Psychol Rep 53:523-535,1983 10. Barber TX:. Hypnosis: A Scientific Approach. New York, Van Nostrand Reinhold, 1969 11. Longo DJ, Clum GA, Yaeger NJ: Psychosocial treatment for recurrent genital herpes. J Consult Clin Psychol 56:61-66 1988
114
Psychosomatic Medicine 52:109-114 (1990)
