The lie scale as a predictor of placebo response

341

NOTES AND SHORTER COMMUNICATIONS

p(.r.~on, inditid. Di~ V o l 2, pp. 341 to 342. 1981 Printed in Greal Britain. All rights reserved

0191 - 8869/81/040341-02 $02.00/~ Copyright O 1981 Pergamon Press Lid

The Lie Scale as a predictor o f placebo response T. G. CROOKES! and P. R. PEARSOS2 tSt John's Hospital, Stone, Aylesbury and "Pastures Hospital, Mickleover, Derby, England (Received 23 February 1981) Summary--Patients engaged in a trial of mepriprazole on the irritable bowel syndrome were administered the Eysenck Personality Questionnaire and the Symptom Rating Test. It was hypothesized that high Lie scorers--'lacking in insight'--would respond to treatment. There was little difference between the active drug and placebo but the results indicated that it was the low Lie scorers who showed improvement, and are interpreted in terms of a repression-sensitization dichotomy.

Lie-scale scores are subject to a number of interpretations (Eysenck and Eysenck, 1976). One such interpretation is that high Lie scorers reflect a 'lack of insight' (Crookes and Buckley, 1976). It may be hypothesized that high Lie scorers are prone to somatize their complaints and consequently are more likely to respond to physical rather than psychological methods of treatment. Furthermore, some studies have shown a relationship between social desirability response bias, acquiescence and 'yea saying' to placebo reaction (Shapiro and Morris, 1978). Therefore, there may well be a relationship between high Lie scores and the placebo effect. An opportunity to investigate the relationship between the Lie scale and response to treatment presented itself in a trial of the effect of mepriprazole on the irritable bowel syndrome (IBS) (Lee et al., 1980). The irritable bowel syndrome is of particular interest here in that a psychiatric component, notably depression, has often been reported (Hdner et al., 1978) and patients with IBS have been found to have high Lie scores (Palmer et al., 1974; Pearson and Lee, 1978). In their trial of mepriprazole, Lee et al. (1980) found that the drug was no more effective with IBS patients than placebo; if anything the subjects on placebo made rather more progress than those on the active preparation. The patients were seen and assessed on three occasions, with a four week interval in each case; between Occasions I and II there was no treatment, so any changes which occurred could be regarded as a 'waiting effect'. From Occasion II to lit, half the subjects were on the active drug and half on placebo. The Eysenck Personality Questionnaire (Eysenck and Eysenck, 1975) was completed by all subjects on Occasion I. The Symptom Rating Test (SRT) (Kellner and Sheffield, 1973) was completed by all subjects on each occasion. In all there were 49 subjects, 24 of whom (10 M, 14 F) had the drug during the second period (Activegroup) while the remaining 25 (10 M, 15 F) were on a placebo, identical in appearance (Placebo group). Table 1 shows the means and standard deviations of the group's scores on the four personality dimensions measured by the EPQ. For a group of both sexes, with a mean age of 34.7 years, their scores do not differ much from the normative values (Eysenck and Eysenck, 1975), except that they are somewhat higher than normal on N. All the personality variables were correlated with the change in SRT score over the treatment period (Occasion lI minus Occasion Ill). The correlations (r) were: P, +0.16, E, -0.08, N, +0.20, L, -0.27. Only that with L approaches significance (0.05 < P < 0.1), and being negative it means, unexpectedly, that the high L scorers showed less improvement than the low. Also this negative correlation between L and improvement was higher in the Placebo group (r = -0.35; 0.05 < P < 0.1) than in the Active group (r = -0.21, NS). To examine this further, the L scores of the whole group were divided at the nearest whole number to the median, to give a high L group, with L greater than 8 (n = 23) and a low L group, with L less than 9 (n = 26). There was no significant age difference between the two groups. Table 2 shows the chaage in SRT score during the treatment period (Occasion II minus Occasion III) for high and low L scorers, active and placebo separately. Plus values indicate an improved state. The t-values indicate the significance of the difference between the pairs of means. In the active group there is no difference between high and low L ~corers, but there is a marked difference between them in the placebo group. Considering each mean separately, i.e. whether the group shows a significant improvement, for the placebo low L group t = 3 . 1 8 , P < 0 . 0 1 ; none of the other three approaches significance. The low L group had a higher initial score on the SRT (X = 18.15) than the high L group (X = 13.48) and it might be argued that their greater improvement over the treatment period was simply that they had further to drop. However, if the waiting period is considered, i.e. before treatment commenced (Occasion I minus Occasion lI), the low L group had a mean improvement of +0.19, while the high L group had a mean of + 1.70. Neither of these is a statistically significant change, but the high L group actually improves more. Thus it is only during the period of medication that the low L group shows the marked improvement compared with the high group. Table

Mean SD

1. EPQ

scores of the total (n = 49)

group

P

E

N

L

3.04 2.09

12.71 5.04

13.37 5.12

9.08 3.56

342

NOTES AND SHORTER COMMUNICATIONS Table 2. Changein SRT during treatment period (SRT II minusSRT IIIL related to L score Group Active High L (>8l(n = II) Low L ( < 9)(n = 13) Placebo High L (>8)(n = 12) Low L (<9)(n = 13)

Mean

SD

t

P

+1.82 + 1.62

5.93 4.68

0.09

NS

+0.92 +6.62

2.68 7.49

2.50

<0.02

Although the other three personality variables showed very small correlations with improvement, they also were divided at the median into high and low scorers in the same way as L. In the active group there was no difference in improvement between high and low scorers on any of the three variables, but there was a relation in the placebo group. This is shown in Table 3, which indicates the SRT improvement scores (Occasion II minus Occasion Ill) for high and low scorers on P, E and N. It can be seen that high scorers have significantly greater improvement than low P scorers, and high N scorers tend to improve more than low. Thus high P and possibly high N are also related to placebo response as well as low L. In the total group L showed the negative correlation with P and N which has been observed elsewhere (Eysenck and Eysenck, 1975). The correlations (r) are; L/P = -0.24, L/N = -0.26. These correlations are quite small, but from the present results it appears that it is the variance which the three measures have in common which is responsible for the differential placebo effect. This may perhaps be related to the findings of Gudjonsson (1981): in response to emotional stimuli subjects were asked to indicate the degree of subjective disturbance on a visual analogue scale and their GSR response was also measured. Those with high GSR responses and low subjective responses were classed as 'repressors', those who claimed high subjective disturbance but had low GSR values as 'sensitizers', those with the two measures concordant being called 'concomitants'. The 'sensitizers' had low L scores and high N scores, (P was not measured), i.e. they resembled our placebo responders. It could be that we have here a personality pattern relevant to a tendency to maximize (or minimize) subjective change. It would represent an extension of the repression-sensitization dichotomy, which is usually thought of as referring to unpleasant experiences only. Where the Lie scale is concerned, the fact that it is the low scorers who show the greatest placebo effect is at odds not only with the 'lack of insight' hypothesis, but also with the 'social conformity' view. It may be useful to consider it in relation to this extended repression-sensitization concept. Hitherto emphasis in the interpretation of the Lie scale has been centred on the characteristics of high Lie scorers (Kirton, 1977). The present study suggests that low Lie scorers require closer scrutiny.

Table 3. Change in S R T during treatment period (SRT II minus SRT Ill),

related to P. E and N. Placebo group only Group High P (>2)(n = 14) Low P (<3)(n ~ 11) High E (> 13)(n = 131 Low E (< 141(n= 121 High N (> 13)(n = 13) Low N (< 14)(n = 12}

Mean

SD

+6.21 +0.91 +3.15 +4.67 +5.54 +2.08

7.08 3.59 6.45 6.34 6.36 5.99

t

P

2.26

<0.05

0.59

NS

1.39

NS

REFERENCES CROOKES T. G. and BUCKLEY S. J. (1976) Lie score and insight. Ir. J. Psychol. 3, 134-136. EYSENCK H. J. and EVSENCK S. B. G. (1975) Manual of the Eysenck Personality Questionnaire. Hodder & Stoughton, London. EYSENCK H. J. and EYSENCK S. B. G. (1976) The nature of the Lie scale. In Psychoticism as a Dimension of Personality. Chapter 11. Hodder & Stoughton. London. GUDJONSSON G. H. (1981) Self-reported emotional disturbance and its relation to el~trodermal reactivity, defensiveness and trait anxiety. Person. indirid. D!ff. 2, 47-52. HEFNER J. D., WILDER R. M. and WILSON I. D. (1978) Irritable colon and depression. Psychosomatics 19, 540-547. KELLNER R. and SHEFFIELDB. F. (1973) A self-rating scale of distress. Psychol. Med. 3, 88-100. KIRTON M. (1977) Characteristics of high lie scorers. Psychol. Rep. 40, 279-280. LEE F. l.. NORFOLK D. R. and PEARSON P. R. (1980) The irritable bowel syndrome: a double-blind trial of mepriprazole. Clin. Trials J. 17, 1-6. PALMER R. L., STONEHILLE., CRISP A. H., WALLER S. L. and MISIEWICZJ. J. (1974) Psychological characteristics of patients with the irritable bowel syndrome. Postgrad. reed. J. 50, 41~419. PEARSON P. R. and LEE F. I. 0978) Personality dimensions and the irritable bowel syndrome: a replication with female patients. I.R.C.S. reed. Sci. 6, 193. SHAPIRO A. K. and MORRIS U A. (1978) Placebo effects in medical and psychological therapies. In Handbook of Psychotherapy and Behat'iour Change: An Empirical Analysis, 2nd edn (Edited by GARFIELD S. L. and BERGIN A. E.). Wiley, New York.