THE AMERICAN JOURNAL OF CLINICAL HYPNOSIS Volume 20, Number 3 , January 1978

Printed in U . S . A .

A Six-month Follow-up of the Use of Hypnosis and Biofeedback Procedures in Essential Hypertension

HOWARD FRIEDMAN, Ph.D. and HARVEY A. TAUB, Ph.D. Syracuse Veterans Administration and State University of New York

Upstate Medical Center at Syracuse

This study, presenting follow-up data over a six-month period, continues a previous investigation (Friedman & Taub, 1977) which dealt with the effects of three procedures, hypnosis alone (HO), biofeedback alone (BO), and hypnosis and biofeedback combined (HB) upon essential hypertensive patients during a training period and brief follow-up. Although both HO and BO were capable of producing decrements in blood pressure, the former, HO, appeared somewhat more effective. The HB procedure continued to offer no advantage over the control “measurement only” (MO) group.

A previous study (Friedman & Taub, 1977) reported upon the relative effective- ness of three procedures, hypnosis alone (HO), biofeedback alone (BO), and hyp- nosis and biofeedback combined (HB), upon essential hypertensive patients over training and brief follow-up periods. Al- though both HO and BO procedures produced decrements in diastolic pressure, the targeted dependent variable, the HO procedure exhibited the more impressive effect, with similar findings in systolic pressure. The HB procedure offered no ad- vantage over a control “measurement only” (MO) group.

The current study continues the investi- gation, reporting on all follow-up data with as many of the same subjects as were avail- able over a six-month period, and involved no further training procedures.

METHOD

Since the technique of measurement, subjects, and procedure for the baseline and

Supported by the Medical Research Service of the Vet- erans Administration.

seven training sessions were fully described in the previous study, they will not be de- tailed again. For the follow-up study, sub- jects returned one week, one month, and thereafter monthly for a total of six months after the last training period. As in a train- ing session, 15 measurements were made automatically with the London Pressureometer, but with no use of hyp- nosis or biofeedback in any subject. Readings were taken at the same time of day as the baseline and training sessions, and each subject waited approximately five minutes prior to the session.

Losses of patients were minimized through the use of telephone and letter con- tacts. Thus only one HO, two BO, and one MO subjects dropped out after the initial investigation, leaving 12 HO, 1 1 BO, 10 HB, and 11 MO subjects for the current study. In the entire group only three sub.- jects had baseline diastolic pressures as low as 85: two HB and one HO. Within the final sample, six subjects missed a total of 12 follow-up sessions, with only one occurring at the six-month period. To permit analyses using the maximum number of subjects, the

184

ESSENTIAL HYPERTENSION 185

12 missing readings were included in the total 352 data points by estimating their values with the technique described in Kirk (1968).

Table 1 provides descriptive data about the subjects,, of the current study. Simple analysis of variance (ANOVA) showed no significant differences between the groups in mean age or in the mean of median dias- tolic or systolic pressures (F < 1 .O).

RESULTS

In order to provide a clear picture of per- sistence of experimental effects beyond the laboratory, the current analyses include the last set of training trials in addition to all follow-up periods. The same type of statis- tical tests as described in the previous study were used. Thus overall effects were examined by ANOVA for repeated meas- ures with one “between groups” variable (treatments) and one “within groups” vari- able (time periods), with a score represent- ing the difference between a subject’s me- dian blood pressure during a session and his baseline pressure. Duncan’s new multiple range test (Kirk, 1968) clarified intergroup differences; and simple ANOVA for re- peated measures assessed changes in any single group from its baseline to subsequent measures with Dunnett’s test examining the significance at each point.

For diastolic pressure there was a sig-

nificant difference between groups (F = 3.21, df = 3,40, p <0.05) with no changes over time. A non-significant interaction ef- fect indicated that the group differences present at the last training session persisted throughout. The HO group with a mean re- duction of 8.5 in median pressure differed significantly ( p <0.05) from the MO group (mean reduction = 2.9). The HB group (mean reduction = 4.0) and the BO group (mean reduction = 7.4) were not significantly different from any other group. Only the HO group changed sig- nificantly (F = 4.65, df = 8 , 8 1 , p <0.001) from baseline, with each point examined showing a significant drop (p <0.01 or p <0.05). The BO group had only a trend toward significant decrement (F = 1.97, df = 8 , 79, p < 0.10). Figure 1 presents the mean of median diastolic pressures at each measurement period.

For systolic pressures, overall ANOVA showed only a trend toward significant “within groups’’ differences (F = 1.87, df = 7 , 268, p <0.10). Only HO and BO groups had significant (p c0.05) decre- ments from respective baselines, with the HO group showing significant drops at the last training session, one week, four months, five months, and six months; and the BO group exhibiting significant de- creases at one through five months. Figure 2 presents the mean of median systolic pressures at each period.

TABLE 1 Age, Sex, Baseline Diastolic and Systolic Pressures, Percent Medicated,

and Hypnotic Susceptibility of Subjects

Mean of Median

Group N Age Males Diastolic Systolic Medicated Hypnotic Susceptibility Range Mean Range Mean

HO 12 35-60 49.1 10 93.5 140.6 62% 7-12 9.8 HB 10 32-53 48.2 8 91.8 139.8 60% a 1 2 10.3 BO 1 1 2%54 47.1 8 95.9 147.3 64% 1-9 3.8 MO 1 1 31-59 48.7 9 95.1 140.8 81% 0-8 3.3

No. Baseline Pressure Percent

186

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95.0

94.0

3 93.0

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88.0- 9 8 87.0

ZE 86.0- LL

850 0 z

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83.0

82.0

FRIEDMAN AND TAUB

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-

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Figure 1

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Baseline Last I I 2 3 4 5 6 training week MONTHS period

MEASUREMENT PERIODS Figure 1 . Means of Median Diastolic Pressure at Each Measurement Period.

DISCUSSION With the initial report (Friedman &

Taub, 1977) oriented primarily toward in- vestigating the effectiveness of the various procedures “within laboratory” and in a brief follow-up, the current study places emphasis upon the follow-up measurement periods. The last training session is also considered within the analyses in order to provide a reference point for persistence of effect beyond the laboratory. The results indicate such persistence most clearly in the HO group. This group showed the only statistically significant overall difference from the control MO group and, further, was the only one that exhibited a consist- ently significant decrement in diastolic

pressure when compared to baseline value. As in the initial investigation, systolic

pressures, though not the dependent vari- able under study, offered findings similar to the diastolic data. Though no overall sig- nificant differences appeared between groups, there were, for the HO and BO groups, statistically significant decrements from baseline.

Although the findings indicate that either HO or BO may be of value in lowering blood pressure, it appears that the former may be somewhat more effective. The magnitude of HO changes, generally in keeping with findings of studies using other psychological procedures, raises the issue of clinical value since the maximum mean

ESSENTIAL HYPERTENSION

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187

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Figure 2.

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MEASUREMENT PERIODS Figure 2. Means of Median Systolic Pressure at Each Measurement Period.

decrease in diastolic pressure was 12% (1 1 . 1 mm Hg.) at five months, with lesser decreases of 9% (8.5 mm Hg.) at four and six months. (Systolic pressures showed comparable results with 1 1 %, 15.9 mm Hg., decrease at five months, and 9%, 13.3 mm Hg. at six months.) These begin to ap- proach, but certainly not reach, the strin- gent criterion (approximately 20%) that Blanchard and Young (1973) have set for clinically significant changes in cardiovas- cular functioning. It is possible, however, that changes of the order of magnitude ob- served in the current study may have clini- cal meaning. Freis (1975), in commenting on the problem of the poorly responsive pa- tient in the treatment of hypertension,

pointed out that the findings of the Veterans Administration Cooperative Studies on An- tihypertensive Agents showed no sig- nificant difference in major cardiovascular complications between poor responders (mean drop of 7 mm Hg. to a diastolic pressure of 98) and good responders (drop of 27 mm Hg. to a diastolic pressure of 76), with a control group of untreated patients showing significantly greater incidence of morbid events than either treated group.

With the HO group showing (a) sig- nificant decrements in blood pressure dur- ing a six-month follow-up with but brief daily practice periods of about three min- utes each, (b) persistence beyond the laboratory training without elaborate in-

188 FRIEDMAN AND TAUB

strumentation or technical devices, and (c) an effect upon diastolic pressure, a depend- ent variable considered relatively refractory to change by psychological methods, the current study invites attention to a poten- tially clinically useful tool which may offer advantages over other procedures. It may well share, however, what could be the common constituent in the broad spectrum of “psychological procedures, ” namely, physical and mental relaxation. This point has already been made by Shapiro and Surwit (1974), and Blanchard and Young (1974) offered the possibility that even biofeedback procedures “. . . may be only elaborate methods for teaching relaxation. ” However, few of the studies in these areas, including those using Benson’s “relaxation response” (Benson, Rosner, Marzetta, & Klemchuk, 1974a, 1974b) have dealt with extensive follow-up periods, particularly with sample sizes and low drop-out rates comparable to those in the current investi- gation, and seem to offer no significant ad- vantage in effect and convenience over hypnosis as used here. Paul (1 969), how- ever, in comparing the relative effects of hypnotic suggestion and brief relaxation training upon reduction of subjective ten- sion and distress and several measures of physiological arousal, found relaxation training superior in affecting response sys- tems not under voluntary control.

The direction of future research would then lie in sharpening the promising tool of hypnosis by determining first whether it is simply another relaxation procedure, albeit an efficient one, or if it has some intrinsic value beyond that of relaxation per se. This issue has been raised by Edmonston ( 1972, 1977). The challenge ultimately, then, is to determine a strategy embodying hypnosis which provides lasting changes of greater magnitude without sacrificing the minimal investment of patient time and effort. Al- though such a strategy may of necessity be limited to that population of hypertensives

with high hypnotic susceptibility, biofeed- back procedures, with effects in the current study similar to that observed in the HO group, offer promise to those individuals not suitable for hypnotic procedures.

Veterans Administration Hospital Irving Avenue & University Place Syracuse, New York 13210

REFERENCES

BENSON, H., ROSNER, B. A., MARZETTA, B. R., & KLEMCHUK, H. M. Decreased blood pressure in borderline hypertensive subjects who practiced meditation. Journal of Chronic Diseases, 1974, 27, 163-169. (a)

BENSON, H., ROSNER, B. A., MARZETTA, B. R., & KLEMCHUK, H. M. Decreased blood-pressure in pharmacologically treated hypertensive patients who regularly elicited the relaxation response. Lancet, Feb. 23, 1974, 289291. (b)

BLANCHARD, E. B ., & YOUNG, L. D. Self-control of cardiac functioning: A promise as yet unfulfilled. Psychological Bulletin, 1973, 79, (3), 145-163.

BLANCHARD, E. B., & YOUNG, L. D. Clinical appli- cations of biofeedback training: A review of evi- dence. Archives of General Psychiatry, 1974, 30, 573-589.

EDMONSTON, W. E., JR. Relaxation as an appropriate experimental control in hypnosis studies. Ameri- can Journal of Clinical Hypnosis, 1972, 14, 218- 229.

EDMONSTON, W. E. , JR. Neutral hypnosis as relaxa- tion. American Journal of Clinical Hypnosis, 1977, 20, 6P-75.

FREIS, E. D. How far should blood pressure be low- ered in treating hypertension? Journal of the American Medical Associat ion, 1975, 232,

FRIEDMAN, H., & TAUB, H. A. The use of hypnosis and biofeedback procedures for essential hyperten- sion. International Journal of Clinical and Ex- perimental Hypnosis, 1977, 25, 335-347.

KIRK, R . E. Experimental Design: Procedures for the behavioral sciences. Belmont, California: BrookdCole, 1968.

PAUL, G. L. Physiological effects of relaxation train- ing and hypnotic suggestion. Journal of Abnormal Psychology, 1969, 4, 42-37.

SHAPIRO, D., & SURWIT, R. S. Operant condition- ing: A new theoretical approach in psychosomatic medicine. International Journal of Psychiatry in Medicine, 1974, 5 , 377-387.

10 17- 101 8.