changing chronic pain experience
TRANSCRIPT
Pain, 32 (1988) 165-172 Elsevier
165
PA1 01136
Changing chronic pain experience
H.C. Philips
Department of Psychology, Shaughnessy Hospital, Vancouver, BC V6H 3Nl (Canada)
(Received 18 August 1986, revised received 22 June 1987, accepted 9 July 1987)
S- Training in relaxation is a prominent component in multi-disciplinary approaches to the management of chronic pain, although its specific potency in modulating pain has not yet been established. Using a within-session design, the specific effects of relaxation induction were evaluated in a group of benign chronic pain patients (n = 24), and compared to similar patients undergoing a control procedure (n = 22). The results indicated that irrespective of the focus of pain complaint, induction of relaxation over a 20 min period led to significant and sizeable reductions in both sensory and affective pain experience. The overall intensity of pain was significantly reduced. These effects were shown to be reliable and independent of onset level of sensory experience or depression. No significant changes occurred in the control group over a comparable period. The implications of these results were discussed with respect to the process by which relaxation reduces pain.
Key words: Relaxation; Chronic pain; Moderation of pain
Introduction
Relaxation is a common treatment component in multi-faceted approaches to the management of chronic pain. These pain management pro- grammes have proved sufficiently potent [14,15,19] to encourage analysis of the contributions made by the treatment components. Theoretical justifi- cations vary as to the reasons for the inclusion of relaxation training (muscular relaxation/reduc- tion of sensory input, control and calming of mental state, etc.), but its importance as a treat- ment technique is well established [l&24,29,32].
Despite the prominence and overall utility [34] of relaxation in managing chronic pain, its specific power in modulating chronic pain experience has not been established. Patients at a behaviourally oriented pain clinic rate a relaxation strategy
Correspondence to: H.C. Philips, Department of Psy- chology, Shaughnessy Hospital, Vancouver, BC V6H 3N1, Canada.
highest in utility over all other strategies taught in a psychologically directed outpatient service [27]. To what extent this reflects the technique’s capac- ity to lower episodes of pain experience and/or provides a greater sense of self-control of pain [10,11,27] is not clear.
The aim of the current study was to evaluate the specific effects of relaxation induction on the experience of constant, chronic, benign pain in a population of individuals attending a chronic pain clinic. Thus, the within-session effects of this pro- cedure upon pain experience could be assessed.
Operant approaches [cf., 12,291 have focused attention upon the assessment and modification of the behavioural indices of chronic pain (activity levels, complaint levels, etc.). Clinics with a pres- sure to prove themselves cost-efficient have in- cluded employment measures and analgesic use, etc. However, paramount to the applicant to the pain clinic is the extent to which he/she will be able to influence, attenuate, or modulate the pain experienced.
03043959/88/$03.50 0 1988 Elsevier Science Publishers B.V. (Biomedical Division)
166
Fortunately, in the last few years, progress has been made in the measurement of pain experience.
Working with the useful preliminary step made by Melzack and Torgerson [22] in the development of
the McGill Pain Questionnaire, a new scale has recently been produced which further dis-
tinguishes aspects of sensory and affective experi- ence [16,17] and enables the comparison of re-
peated assessments. Although developed for a
headache population, it uses adjectives from the McGill Pain Questionnaire and is suitable for any
type of pain. The scale reliably distinguishes 5
separable clusters or aspects of sensory pain expe-
rience and two clusters or aspects of affective pain
experience. This scale has been found to be relia- ble and valid 1171. With a scale of this sort, it
becomes feasible to examine the specific effects of a procedure such as relaxation on pain experience
itself. The feasibility of‘ such an approach was
demonstrated in a study of Melzack and Perry [21]. Using the McGill Pain Questionnaire, they
demonstrated significant changes in both sensory
and affective dimensions of chronic pain as a result of alpha feedback and hypnotic training.
Component analyses of psychological treat-
ment approaches have yet to be published, prob- ably because of complex statistical problems raised
by the assessment of a multi-dimensional phe- nomenon treated with a multi-faceted approach. In the meantime, it is feasible to examine individ-
ual components of the treatment approaches and
assess their strengths in controlling pain experi- ence per se. A start is made in this study by
limiting the evaluation to within-session effects of
relaxation upon constant chronic pain experience.
TABLE I
Subjects
In all, 46 chronic pain patients attending chronic pain management service were studied.
Twenty-four of these patients (experimental group) were evaluated before and after a 20 min relaxa-
tion induction, while twenty-two (control group) were evaluated before and after a 20 min period in which they listened to a didactic presentation on
the nature of chronic pain. Table I below provides
details of the age, sex distribution. pain type. pain
chronicity, and average pain intensity in the two
groups.
Design and instruments
The Headache Scale [16,17] was given to these patients before and after either the induction of
relaxation or the didactic presentation, in order to
get an evaluation by each patient of his/ her pain experience (occasion 1). This scale consists of 30
adjectives commonly utilized by those in pain, 27 being selected from the McGill Pain Question- naire [22]. Each adjective can be rated by the
subject from 0 to 3 (0 = not at all; 1 = mild; 2 = moderate; 3 = severe). Cluster analysis has re-
vealed 7 distinguishable clusters, 5 of which are sensory and the remaining 2 affective. These clus- ters have been labelled as follows: sensor)
‘ache’ (Sl), ‘sharp’ (S2). ‘tight’ (S3), ‘autonomic’
(S4). ‘dull’ (S5): affective - ‘discomfort’ (Al), ‘anxiety/depression’ (A2). This scale allows a di-
rect quantitative comparison of sensory and affec- tive components when the questionnaire is used
AGE, SEX DISTRIBUTION, CHRONICITY, SEVERITY, AND CHRONIC PAIN TYPE OF SUBJECTS (n = 46) DIVIDED
INTO RELAXATION (n = 24) AND CONTROL GROUPS (n = 22)
Age Sex dist.
(yr) (F/M)
Type
Back Head Other
chronicity
(yr)
Severity
(O-5)
Relaxation group (n = 24)
Control (n group = 22)
40.12 20/4 41% 29% 30% 1.7 2.6
(12.04) (6.80) (0.84)
38.0 18/4 31% 31% 38% 10.5 2.63
(9.3) (8.65) (@.%)
167
on repeated occasions. The latter is not possible using the McGill Pain Questionnaire.
In addition to this scale, subjects were asked to give overall pain intensity ratings using an ana- logue scale from 0 to 5 (the PPI-McGill Pain Questionnaire: 0 = no pain to 5 = intense and in- capacitating pain).
The experimental group (24) cases seen before and after the relaxation induction were assessed in an exactly replicable manner 1 week later using the same induction procedure (occasion 2). These 2 occasions will be referred to as occasion 1 and occasion 2. The control group (pre- and post-di- dactic presentation) was evaluated only on occa- sion 1 and provides the control data for this study.
Roeedure
Relaxation induction followed the guidelines of Bernstein and Borkovic [4], although a simplified 9 muscle group method was used on both occa- sions (transcript available from the author). Em- phasis was also placed on slow, regular, di- aphragmatic breathing which was to be used throughout. None of the patients had received any training in relaxation prior to this first session.
All patients, irrespective of group (control or experimental), were asked to fill in the Headache Scale at the onset in order to indicate their current pain level and its qualities. Immediately post-in- tervention (relaxation induction or didactic on pain, both of 20 min duration), they were asked again to use the scale to indicate their current pain level and its qualities. Neither group was given any expectations with respect to immediate effects of the interventions, both being presented as im- portant ingredients in a 9 week programme for the management of chronic pain.
The Headache Scale was analysed to give scores (range O-3) for each of the 5 sensory clusters and the 2 affective clusters [16].
Results
(I) Experimental and control group comparability The characteristics of the 2 groups of chronic
pain cases can be found in Table I. They are
typical of cases referred for treatment [27] both in the sex distribution, chronicity, and in pain inten- sity characteristics. The average severity estimates are obtained from 1 week of self-monitoring (O-5 ratings using the pain diaries [6]). They demon- strate the intensity of the daily chronic pain prob- lem endured by these individuals.
No significant difference was found between the two groups on any of these measures.
(2) Pre-intervention differences Below can be found a table of means (Table II)
for each of the sensory and affective clusters mea- sured by the Pain Questionnaire, and the pain intensity estimates (PPI O-5 scale) for the experi- mental groups on 2 separate occasions and for the control group.
For each occasion, the null hypothesis was tested: that the mean (vector) in the experimental group, pre-intervention, was the same as that of the control. For the sensory and affective mea- sures (considered as multi-variate vector re- sponses), 2-sample Hotelling T2 tests were per- formed. Occasion 1: sensory vector Hotelling T2 = 5.27, P = 0.45; affective vector Hotelling T2 = 4.60, P = 0.12. Occasion 2: sensory vector Hotel- ling T2 = 2.87, P = 0.76; affective vector Hotel- ling T2 = 0.85, P = 0.66). Thus, no evidence was found of any significant differences between the
TABLE II
PRE-INTERVENTION: MEANS FOR SENSORY @l-5),
AFFECTIVE CLUSTERS (Al, 2) AND PPI (pain intensity)
ON THE TWO OCCASIONS FOR THE EXPERIMENTAL
GROUP AND FOR THE CONTROLS
Means at ‘ pre’:
Experimental Control
Occasion 1 Occasion 2
Sl 1.21 0.93
s2 0.72 0.52
s3 1.26 1.17
S4 0.64 0.50
SS 0.92 0.88
Al 1.85 1.48
A2 0.86 0.75
PPI 3.05 2.40
0.90
0.46
0.84
0.50
0.82
1.32
0.58
2.43
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TABLE III
MEAN (vectors) OF DIFFERENCE BETWEEN PRE AND POST SCORES FOR THE TWO GROUPS (experiment and controls) ON OCCASION 1
hp. Control
Sensory Sl -0.400 0.064 s2 - 0.356 0.091 s3 - 0.571 - 0.107 s4 -9.211 0.062 s5 - 0.375 - 0.048
Affective Al - 0.963 0.119 A2 - 0.421 0.058
PPI -0.914 0.245
experimental and control subjects on either oCca- sion on the sensory or affective clusters.
The &in intensity (PPI) was analysed using a univariate, 2-sample t test (t = 1.479, df= 39, P = 0.09). This test also showed no evidence of any experimental/control differences pre-intervention.
(3) The eflects of relaxation induction To evaluate the experimental effect of relaxa-
tion, the experimental and control groups were compared at occasion 1, before, and after the 20 min interventions (relaxation induction versus di- dactic control). Taking a post-minus-pre vector of differences, the null hypothesis assessed that the mean vector of differences of both groups would be the same, Hotelling T2 (2 samples) were per- formed for both sensory and affective measures, while a univariate Z-sample t test evaluated PPI changes.
All tests were significant, indicating a specific shift in sensory and affective components of pain experience, as well as the overall PPI score (sensory Hotelling T2 = 24.14, P = 0.003; affective Hotel- ling T2= 26.9, P=O.OOO; PPI t =4.81, df= 29, P = 0.001 (two sided) in the experimental group).
The consistently negative differences on all measures for the experimental group (see Table III) indicate that relaxation leads to reduction in pain experience consistently across all measures. The control group shows very little change, most of which is in the direction of increased pain.
A comparison of the experimental group on occasion 2 with the controls allows an evaluation
of the repli~ability of the above results. Exactly
the same type of analyses were performed 3s pre- viously (see 3 above). Again, relaxation had a significant effect on ail 3 sets of measures (sensory
Hotelling T* = 11.36, P = 0.013: affective Hotel- ling T2 = 43.06. P = 0,000: PPI t = 4.09, Q’=- 39. P = 0.002 (two-sided)), A replication of the experi-
mental effect was evidenced.
(5) The difference between occasions in a relaxation effecr
If the magnitude of relaxation effect were the same on the 2 occasions, the difference (post minus pre) on the 2 occasions would be the same. To assess this, the difference between differences on the 2 occasions was taken. If the relaxation effect was the same in magnitude, this last mea- sure would be predicted to be zero. The Hotelling T2 tests for both sensory and affective measures were as follows: sensory Hotelling T* = 22.17, P = 0.017; affective Hotelling T2 = 1.09, P = 0.60. Thus the magnitude of effect for the sensory com- ponent differed between occasions while the affec- tive component showed no change. A comparable approach on the pain intensity (PPI) revealed the magnitude of the relaxation effect to be the same on the 2 occasions for this measure (t = 0.45, df = 15. P = 0.66 (two sided)).
(6~ Differences between pain groups with respect to the effect of relaxafion
No significant differences were found between the 3 types of pain in this population of chronic pain patients (back, headache, and other - facial, pelvic, multiple, etc. (Table I)) in their response to relaxation induction.
(7) Aspects of the pain experience The inventory used allows analysis of the vari-
ous clusters that comprise the pain experience dividing into sensory and affective aspects. Pre-in- tervention, the affective cluster was significantly higher than the sensory cluster score when occa- sions 1 and 2 were summed (F = 67.8, 1, 23. P -z 0.0000). The sensory factor total at onset was
169
TABLE IV
INTERRELATION OF CHANGE SCORES FOR SENSORY AND AFFECTIVE PAIN EXPERIENCE TOTALS OF PAIN INTENSITY RATINGS
Sensory Affective PPI
Sensory total -
Affective total
PPI
r = 0.72 r = 0.56 P < 0.000 P < 0.02
r = 0.39 ns
not significantly correlated, however, with changed scores (post-pre-relaxation). However, for the af- fective total, the association was significant (r = -0.52, P < 0.01). Thus the higher the affective scores at onset, the smaller the reduction pro- duced by relaxation induction.
The table above (Table IV) gives the correla- tions between change scores. Sensory and affective component changes have 52% of variance in com- mon. The relationship of overall intensity ratings and sensory/affective component change scores is much weaker. Pain intensity changes appear to be unrelated to the affective shift that occurs.
The mean depression score for the total group of experimental subjects was 16.17 on the Beck Depression Inventory thus placing them in the mild depression range [2]. The depression scores were significantly associated with the affective and sensory pain totals prior to occasion 1 (affective total: r = 0.67, P < 0.0000; sensory cluster: r = 0.61, P < 0.001). Higher depression scores were found with higher pain levels, as assessed on the sensory or affective dimension. However, no rela- tionships between depression scores and change scores were found for either dimension.
Discussion
The characteristics of the chronic pain patients evaluated in this study are representative of the level and type of distress found in individuals who are battling constant pain experience over ex- tended periods of time. The larger proportion of females in this study reflects the clinic’s exclusion- ary criteria which screen out all individuals cur- rently involved in litigation.
The inventory used to assess pain experience allows the differentiation of sensory and affective aspects of pain experience. These individuals show a much higher level of affective pain experience than sensory, though both are at a clinically sig- nificant level. The raised affective component em- phasizes the importance of pain management ap- proaches focusing upon, and developing, tech- niques to help individuals to deal with this emo- tional reaction to prolonged pain.
As has been noted frequently in the past [cf., 301, these chronic pain patients reveal mild levels of depression. The latter is significantly and posi- tively correlated with the level of pain experience be it affective or sensory in quality.
Irrespective of the focus of the pain complaint, the induction of relaxation over a 20 min period in previously untrained chronic pain patients led to a significant and sizeable reduction both in sensory and in affective pain experience. In addition to the lowering of the level of both of these dimensions, the overall intensity of pain (PPI) was also signifi- cantly reduced. The use of the inventory allowed this more usual and blunt evaluation of pain to be extended to the many types of experience that are incorporated in an intensity index. It appears that the reductions produced by relaxation occur across all the clusters assessed by the inventory, be they sensory or affective in quality. Gracely et al. [13] have been able to show that the common minor tranquilliser (diazepam) can affect pain experience in a specific way. The sensory component of the pain experience remains unchanged while the af- fective emotional reaction to pain was signifi- cantly reduced. In this case, with a relaxation induction, both the sensory and the affective reac- tion were significantly affected suggesting that relaxation induction entails more than a minor tranquillising effect. It appears to significantly alter the sensory/ discriminative dimension of chronic pain, influencing as it does many types of sensation: tightness, aching, sharpness, etc.
This experimental effect produced by the sim- ple induction of relaxation was shown to be relia- ble by its replication 1 week later in the experi- mental group. The size of effect on the affective component and on the pain intensity rating was comparable on these 2 occasions, although there is
170
some suggestion that there is some change in the focus of the sensory change on the second occa-
sion. Although the shift remains significant, the relevant contribution of the 5 sensory components
varied to some extent. To what extent this is a learning effect, as the subjects become more profi-
cient at relaxation induction, will need to be fur- ther investigated.
Chronic pain patients with different pain prob- lems benefitted equally from the induction of re-
laxation procedures. There is no suggestion that
one pain type benefitted more from learning to
relax. This fact has implications for those working
with chronic pain patients and wishing to utilize a
group format. It appears to be a technique which will be useful for all chronic pain patients and, as
it can readily be induced in a group, can be utilized as an important strategy which will help individuals in that group irrespective of the dif-
ferences in pain focus. The size of the response to relaxation was in-
dependent of the onset levels of sensory experi-
ence or of depression. Thus, extremely high levels of sensory experience or depressive scores, at least
in the mild range, would not appear to be ap-
propriate reasons for excluding individuals from pain management approaches that utilize a relaxa-
tion technique. On the other hand, the affective
change produced by relaxation was smaller when the affective component was higher. Individuals
with extremely high affective scores pre treatment may need more than relaxation training to manage their problems.
The high correlation between sensory and af- fective change suggests the integrated way in which relaxation influences pain experience. The failure
of pain intensity rating changes to correlate highly
with sensory or affective changes underlines the bluntness of this simple rating scale to assess the changes in experience. Interestingly, this overall rating seems to be most influenced by the sensory dimension of pain experience, and its bluntness may well be predominantly related to its inability to accurately reflect the changes in affective pain experience. Prior to the relaxation induction, the overall pain intensity (PPI) was significantly re- lated to affective total (r = 0.59; P < 0.005) and to sensory total (r = 0.65; P c 0.001). Although
reflecting to some extent sensory and ;tffective qualities, the weakness of PPI is much more evi- dent in its inability to reflect changes in the
affective emotional reaction to pain. at least in this context.
In summary, it appears that relaxation without former training can have a specific muting or attenuating effect upon persisting chronic pain experience. This suggests the importance of in-
cluding progressive relaxation techniques in the training battery for chronic pain patients, both as
a general component in training as well as a
specific episodic control strategy which can be
utilized when pain levels peak beyond a point
where they can be disregarded. Further training in
relaxation may well produce more sizeable reduc- tions as well as quicker ones. The relative potency
of relaxation at difference levels of pain experi- ence would be an interesting further investigation to clarify the relative potency of relaxation induc- tion for these patients.
To further clarify the process by which progres-
sive relaxation leads to changes in pain experience concurrent psychophysiological assessment and
ratings of subject arousal/anxiety must be in- cluded in future studies. This additional informa-
tion would help unravel the way in which such a simple intervention as relaxation modulates a
long-standing and continuing pain problem. Some researchers have presumed relaxation induction to
be effective in its capacity to reduce sensory dis- criminative input [1,32]. However, as relaxation
has been shown to reduce arousal and anxiety. it is possible that relaxation produces its effect via modulation of the affective/motivational dimen- sion of pain experience. Recently it has been shown that pain perception is significantly in-
fluenced by the induction of relevant anxieties [35]. The correlation between sensory and affec-
tive pain experience would suggest that in order to further clarify this issue, independent measures of anxiety and muscle tension would be a useful step to take in teasing out the focus of effect produced by relaxation induction.
In conclusion, this study has made clear the relevance and importance of training any type of chronic pain patient in the use of relaxation proce- dures. Relaxation produced consistent reductions
in all aspects of the pain experience, be they sensory or affective. As this study evaluated the effects of only the first 2 sessions of relaxation training, it is possible that the speed of reduction and/or its size may be further increased as train- ing continues. The demonstration to patients that they can, over a short period, modulate their dis- tress by a simple technique is of great potency at the onset of training.
Acknowledgements 16
Thanks are due to Tania Deans for preparing the manuscript, and to the Statistics Department at the University of British Columbia for their advice in data analysis.
References
1
2
3
4
5
6
7
8
9
10
11
Bakal, D.A., The Psychobiology of Chronic Headache,
Springer, New York, 1982.
Beck, A.T., Ward, C.H., Mendelson, M., Mock, J. and
Erbaugh, J., An inventory for measuring depression, Arch.
gen. Psychiat., 4 (1961) 561-571.
Beecher, H.K., The Measurement of Subjective Responses,
Oxford University Press, New York, 1959.
Bernstein, D.A. and Borkovic, T.D., Progressive Relaxation
Training. A Manual for Helping Professions, Research
Press, Illinois, 1973.
Blanchard, E.W. and Andrasik, F., Psychological assess-
ment and treatment of headache: recent developments and
emerging issues, J. consult. clin. Psychol., 50 (1982) 859-879.
Budzynski, T.H., Stoyva, J.M. and Adler, C., Subjective
assessment of pain and its relationship to the administra-
tion of analgesics in patients with advanced cancer, J.
psychosom. Res., 10 (1973) 203-308.
Chapman, C.R., Pain: the perception of noxious events. In:
R.A. Stembach (Ed.), The Psychology of Pain, Raven Press,
New York, 1979, pp. 169-202.
DeGoode, D.E., A behavioural pain management program:
expanding the psychologists’ role in the medical setting,
Prof. Psychol., August (1979) 63-78.
Dolce, J., Pain management: a reaffirmation, Behav. Ther.,
7 (1984) 38-50.
Dolce, J.J., Cracker, M.F., Moletteire, C. and Doleys, D.M., Exercise quotas, anticipatory concern and self-efficacy ex-
pectancies in chronic pain, Pain, 24 (1986) 365-372.
Dolce, J.J., Doleys, D.M., Raczynski, J.M., Lossie, J., Poole,
L. and Smith, M., The role of self-efficacy expectancies in
the prediction of pain tolerance, Pain, 27 (1986) 261-272.
12
13
14
15
17
18
19
20
21
22
23
24
25
26
27
28
29
Holroyd, K.A., Recurrent migraine and tension headache.
In: K. Holroyd and T. Creer (Eds.), Self-Management of
Physical Disease. Developments in Health, Psychology, and
Behavioural Medicine, Academic Press, New York, 1985.
Hunter, M., The headache scale: a new approach to the
assessment of headache pain based on pain descriptions,
Pain, 16 (1983) 361-373.
Jahanshahi, M., Hunter, M. and Philips, H.C., The headache
scale and examination of its reliability and validity,
Headache, 26 (1986) 76-82.
Lange, P.J., Fear reduction and fear behaviour: problems
in treating the construct. In: J.M. S&lien (Ed.), Research in
Psychotherapy, American Psychological Association,
Washington, DC, 1978.
Linton, S.J., A critical review of behaviour treatment for
chronic benign pain other than headache, Brit. J. clin.
Psychol., 20 (1986) 321-337.
Melzack, R. and Loeser, J.D., Phantom body pain in
paraplegics: evidence for a central ‘pattern generating
mechanism’ for pain, Pain, 4 (1978) 195-210.
Melzack, R. and Perry, C., Self-regulation of pain in the use
of alpha-feedback and hypnotic training for the control of
chronic pain, Exp. Neurol., 46 (1975) 252-269.
Melzack, R. and Torgerson, W.S., The language of pain,
Anesthesiology, 34 (1971) 50-79.
Melzack, R. and Wall, P.D., The Challenge of Pain, Penguin
Books, Middlesex, 1982.
Mitchell, K.R. and White, R.G., Behavioural self-manage-
ment: an application to the problem of migraine headache,
Behav. Ther., 8 (1977) 213-222.
Newman, RI., Seres, J.L., Yossep, L.P. and Garlington, B.,
Multidisciplinary treatment of chronic pain: long-term fol-
low-up of low-back pain, Pain, 4 (1978) 283-292.
Paul, G.L., Insight Versus Desensitization in Psychother-
apy, Stanford University Press, Stanford, CA, 1966.
Philips, H.C., The effects of behavioural treatment on
chronic pain, Behav. Res. Ther., 25 (1987) 365-378.
Philips, H.C. and Jahanshahi, M., The effects of persistent
pain: the chronic headache sufferer, Pain, 21 (1985)
163-176.
Roberts, A.H. and Reinhardt, L., The behavioral manage-
ment of chronic pain: long-term follow-up with comparison
groups, Pain, 8 (1980) 151-162. 30 Romano, J.M. and Turner, J.A., Chronic pain and depres-
sion: does the evidence support a relationship?, Psychol.
Bull., 97 (1985) 18-34.
31 Stembach, R.A., Pain: a Psychophysiological Analysis,
Academic Press, New York, 1978.
171
Fordyce, W.E., Behavioural Methods for Chronic Pain and
Illness, Mosby, St. Louis, MO, 1976.
Gracely, R.H., McGrath, P. and Dubner, R., Validity and
sensitivity of ratio scales or sensory and affective verbal
pain descriptors: manipulation of affect by diazepam, Pain,
5 (1978) 19-29.
Guck, T.P., Skultety, F.M., Meilman, P.W. and Dowd,
E.T., Multidisciplinary pain center follow-up study: evalua-
tion with a no-treatment control group, Pain, 21 (1985)
295-307.
172
32 Turk, DC., Meichenbaum, D. and Genest, M., Pain and 34 Turner, J.A. and Chapman, C.R., Psychological mterven-
Behavioral Medicine: a Cognitive Behavioral Perspective, tions for chronic pain: a critical review. I. Relaxation
Guilford Press, New York, 1983. training and biofeedback, Pain, 12 (1982) 1-21.
33 Turner, J.A., Comparison of group progressive relaxation 35 Weisenberg, M., Aviram, O., Wolf, Y. and Raphael;, N.,
training and cognitive behavioural group therapy for chronic Relevant and irrelevant anxiety in the reaction tn pain.
low back pain, J. consult. clin. Psychol., 50 (1983) 757-765. Pain, 20 (1984) 371-385.