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Aversion therapy: Chemical or electrical?
AVERSION THERAPY:
CHEMICAL
OR ELECTRICAL?
S. RACHMAN Institute of Psychiatry,Universityof London (Received 28 December 1964)
AFTERa period of considerable activity during the forties,* research workers appeared to lose interest in the therapeutic possibilities of aversion conditioning. The resurgence of interest in aversion therapy (in Britain at least) can partly be attributed to the publication of Raymond’s (1956) account of treatment of a fetishist by apomorphine conditioning. The response to this paper was, of course, enhanced by the growth of behaviour therapy and in the past few years many successes with aversion treatment have been reported (see reviews by Rachman, 1961; Franks, 1960, 1963; Eysenck and Rachman, 1965). Anyone who contemplates using this form of treatment must first make a decision about the type of noxious stimulus which he is going to employ. In view of the considerable and widespread interest in the practical and theoretical aspects of aversion treatment it is opportune to consider the choice available to therapists at the present time. To date most of the cases reported in the literature have been treated by chemical aversion methods but there are sound reasons for believing that electrical methods may be preferable (Eysenck, 1960; Rachman, 1961). The purpose of this paper is to consider the advantages and disadvantages of the chemical and electrical methods and to draw attention to the possible superiority of the electrical method. Aversion treatment, particularly chemical aversion, can be an unpleasant and arduous form of therapy and this fact, coupled with the often equivocal results obtained in the treatment of alcoholics, probably contributed to its decline in popularity. Franks (1960, 1963) has already drawn attention to the poor quality of much of the early work on aversion treatment of alcoholics. “. . . Unfortunately, not all modern practice is sound. . . For example, some clinicians advocate giving the alcohol after the patient reaches the height of nausea. This of course, is backward conditioning (since the unconditioned stimulus of the apomorphine or the emetine is preceeding the conditioned stimulus of the alcohol) and backward conditioning, if it occurs at all, is at best very tenuous, . . .” (Franks, 1963). In any conditioning situation, the time intervals which elapse between the presentation of the various stimuli and the response are of considerable importance and some aversion therapists appear to have been ignorant of this fact or tended to ignore it. Franks writes that “. . . under such circumstances, it is hardly surprising that reports of evaluation studies range from virtually zero success to 100 per cent success”. The choice of nausea-producing drug has also given rise to difficulty. Some of the drugs which have been used to produce nausea also act as central depressants. This type of drug would interfere with the acquisition of the conditioned response. There is, furthermore, * Miller et aI. (1964) have traced 169 references to conditioning procedures in the literature OD
alcoholism.
289
290
S. RACHMAN
some confusion about the nature of the particular response which one is attempting to attach to the sight, smell and taste of the alcohol. Tn some of the earlier studies therapists stressed the action of vomiting rather than the feeling of nausea. As Raymond (I 964) has shown, however, the action ofvomiting is not the importantevent-it is the feeling of nausea which influences the acquisition of an avoidance reaction to alcohol. The failure to distinguish between the feeling of nausea and the actual vomiting is a prominent feature of the majority of reports of chemical aversion treatment and this confusion increases the difficulty of assessing the effectiveness of numerous series of case reports. The problems involved in chemical techniques of aversion conditioning are multiplied by the existence of individual differences in reactivity to the various nausea-producing drugs. People differ in the speed and extent of their reactions to the various drugs and, furthermore, the same person may react differently to the same quantity of drug on different days or even at different times on the same day. Individual differences in reactivity, therefore, make the planning of a carefully controlled form of conditioning treatment extremely awkward, The use of chemical noxious stimuli also precludes the possibility of making accurate measurements of the unconditioned and conditioned responses which are being elicited. While it is possible, of course, to obtain measurements of reaction latency, it has proved extremely difficult, if not impossible, to obtain measures of magnitude of the responses produced. Because of the arduous, complicated and unpleasant nature of the chemical aversion conditioning sessions, it is impractical to provide frequent repetitions of the association between the conditioned stimulus and the unconditioned stimulus. The nun~ber of conditioningpresentations and the number of sessions which can be provided are, therefore, inherently restricted. These restrictions not only increase the duration of the treatment period, but they also limit the number of conditioning trials which can be carried out. The treatment is unpleasant, not only for the patient, but also for the therapist and the nursing staff. It is not uncommon for attendants to object to participating in this form of treatment and there can be no doubt that it arouses antagonism in some members of the hospital staff. Complaints about the method being unaesthetic and even harrowing are not entirely without justification-it is certainly a method which does not lend itself to popularity. The unpleasant nature of this treatment also makes it rather difficult to arrange for patients to be treated on an out-patient basis. There is also some clinical evidence to suggest that chemical aversion treatment brings about increased aggressiveness and hostiIity on the part of the patient (~orgenstern and Pearce, 1963). It should be pointed out, however, that some of these reactions to chemical aversion therapy are not entirely surprising; it has been observed experimentally that the administration of aversive stimulation of various kinds can give rise to an increase in aggressive behaviour (Martin, 1963). It may, indeed, prove necessary to develop special methods for managing the increased aggression, if and when it occurs. A second difficulty which may be anticipated in most forms of aversion therapy concerns the anxiety of the patient. It has been suggested (Eysenek and Rachman, 1965) that there is a possibility that highly anxious patients may respond unfavourably to aversion treatment. Finally, it should be mentioned that some of the drugs which have been used in chemical aversion treatment have unpleasant side-effects and can be dangerous, Certainly, chemical aversion cannot be used for the trea~ent of patients with gastric ailments or cardiac complaints. Despite the difliculties enumerated above and the indifferent quality of a great deal of the work on chemical aversion treatment, some remarkable successes have, nevertheless, been achieved. Voegtlin and his colleagues (Voegtlin and Lemere, 1942; Lemere and
AVERSION
THERAPY:
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OR ELECTRICAL?
291
Voegtlin, 1950) obtained creditable results in their treatment of over 4000 alcoholic patients. Raymond (1964) has reported successes in treating alcoholics, sexual perverts and drug addicts; Morgenstern and Pearce (I 963) have had encouraging results in their treatment of transvestites and so forth. Despite the fact that this method is often marred by a high relapse rate, there is no escaping the fact that many otherwise untreatable patients have obtained substantial benefits (and in many cases cures) from chemical aversion treatment. It should also be emphasized that the types of disorders that have yielded successes are precisely those kinds of abnormalities which are ordinarily resistant to change. Certainly, until the advent of aversion therapy there was little that could be offered to patients with sexual perversions such as fetishism, transvestism and the like. One of the earliest reports of an electrical aversion method was a brief account given by Max (1935) of the elimination of a homosexual fixation by the administration of brief electric shocks. This suggestive paper was apparently ignored however. In view of the extensive use made of electrical stimulation in avoidance conditioning experiments, it is curious that therapists have neglected to apply these findings until fairly recently. The bulk of the available laboratory evidence on avoidance conditioning (and there is a considerable amount of such evidence) concerns experiments in which the aversive stimulus was an electric shock. This is the first, and potentially the most important, of all the advantages offered by electrical methods of aversion treatment. Over the past few decades psychologists have accumulated a wealth of detailed information about the effects of electrical stimulation on behaviour, and while it is true that there are many problems which have yet to be resolved, there is also little doubt that the information which is already available can help tremendously in the design and conduct of aversion treatment. An encouraging start in this direction has already been made by Feldman and MacCullough (1965) who have demonstrated in a very clear manner how it is possible to construct a therapeutic programme from fundamental findings in the field of aversive conditioning. An importanttheoretical contribution to the understanding of the effects of aversive stimulus on behaviour was recently made by Church (1963). Summing up the position, Church writes : “In comparison with a procedure involving no aversive stimulation, the effects of punishment are varied. If punishment reinstates a condition of original training, or it elicits a response similar to the act being punished, then the procedure may produce response facilitation. Otherwise, punishment will produce response suppression”. If the aversive stimulation is not contingent upon the discriminative stimuli, “ , , . the effect of punishment is simple . . . it always produces suppression”. The effectiveness of aversive electrical stimulation depends on numerous factors, such as the intensity of the stimulus, the amount and kind of previous training, the person’s drive level, time relations between the administration of the stimulus and the occurrence of the response. Information concerning all of these (and other) relevant variables can be found in the literature on experimental psychology and employed in the design of effectiveness of aversion treatment (see the discussion in Eysenck and Rachman, 1965). Electrical stimulation can be precisely controlled. The therapist is in a position to administer a discrete stimulus of precise intensity for a precise duration of time at precisely the required moment. In this respect electrical aversion stimulation is clearly superior to chemical aversion. Each of these variables can be manipulated according to requirements and the entire treatment process becomes considerably more flexible. The greater control which is possible with electrical stimulation should ensure more effective treatment, closer definition of the treatment process and increased theoretical clarity.
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S. RACHMAN
Chemical techniques do not provide much scope for ~nodifi~ations which might be introduced on the basis of the patient’s personality. Individlia~ differences tend to be blotted out because the chemical aversion procedures cannot be ~llanipulated with precision. For example, the observation that extraverts have a greater toferance for pain than introverts (Lynn and Eysenck. 1961) could not be used to advantage. Lynn and Eysenck obtained a correlation of 0.69 between extraversion and pain tolerance in a group of 30 students and Poser (1960) reported a correlation of 0.53. Other relevant reports are quoted by Lynn and Eysenck and these, coupled with the suggestion that extraverts can tolerate more intense electric shocks than introverts (Becker, 1961), may produce useful modifications of the electrical method. Certainly, individual differences in reactivity to, and tolerance for, electric shocks can be incorporated in electrical aversion treatment. When the relationships between personality and these variables have been worked out in greater detail, it should be possible to provide treatl~~etlt schedules which will be designed to meet the needs of the individuai patient. In addition, the increased therapeutic control provided by electrical stimulation permits the therapist to make accurate measurements of the progress of treatment. For example, Rachman (1961) gives a brief account of the technique of mcasuremcnt which he used in tracing the effectiveness of electrical stimulation on the sexual images of a fetishist. It was found that as the number of associations between fetishistic-transvestite impulses and electrical stimulation was increased, the patient found it increasingly difficult to conjure up the images. The duration of the images showed a concomitant decrease. It was found possible to make exact measurements of both latency and duration of the response (image). This enabled the therapist to plot the course and progress of the treatment. Similar measurements have been reported by McGuire and Vatlance (1964) and by Feldman and Ma~C~~lfoug~~(1964f. ~eas~tren~ents of the patient’s reactions at each stage of the treatment are valuable in their own right and also because of the information which they provide about the relationship between imagery and action. With the accumulation of research on this topic it should be possible to work out in some detail the relationship between, say, images of sexual perversions and the real act. Tn particular it would be very interesting to see whether or not the reductions in frequency and duration of the images are accompanied by similar reductions in the patient’s overt activity and, if they are, whether there is any time lag in the transfer from imagery to actual behaviour. Unlike chemical aversion treatment, electrical stimulation permits frequent repetitions of the association between the unwanted behaviour and the noxious stimulus. it is perfectly feasible to present a large number of trials to the patient during one session and also to provide for nunlerous conditioning sessions within the same day. This should enable treatment to progress more quickly. It is also feasibIe to construct portable apparatus for the delivery of the shocks and this allows treatment to be carried out on an out-patient basis. In some cases the patient can even administer the noxious stimulus to himself, if and when the necessity arises. A recent example of self-administered electrical stimulation was reported by Wolpe (1965). In this report, he described the partially successful treatment of a patient who was suffering from a drug-addiction. It was possible to bring about a temporary suppression of drug craving by getting the patient to administer the electric shock to himself whenever the craving arose. The apparatus which was used in this case was that described by McCuire and Valiance (1964).
AVERSION
THERAPY
:
CHEMICAL
OR ELECTRICAL?
293
Experience with chemical aversion methods leads us to expect a rather high relapse rate in aversion treatment generally. A similar situation has, of course, been encountered in the conditioning treatment of enuresis (Gwynne Jones, 1960). In an attempt to obtain greater stability of nocturnal continence in the patients treated by the bell-and-pad method, Lovibond (1963) adniinistered his conditioning programme on an intermittent reinforcement schedule. Although it is not yet possible to reach a firm conclusion about the long term effectiveness of the intermittent reinforcement schedule used in this type of disorder, there are very strong grounds for believing that intermittent reinforcement schedules may indeed provide a key to the reduction of relapse rate in aversion treatment. Certainly, intermittent reinforcement is very much simpler to programme if one employs an electrical stimulus rather than drugs. Another possible technique for reducing the relapse rate is the use of booster treatments and these, too, are more feasible with the electrical method, especially as it is possible to construct portable apparatus. This might permit the patient to administer the booster treatments to himself when necessary. Another difficulty which can be overcome by the substitution of electrical for chemical aversion methods concerns the staff problems mentioned earlier. Electrical treatment does not require more than one therapist to be present and it is considerably less arduous and cumbersome (see McGuire and Valiance, for example). With the possible exception of patients with cardiac complaints there is virtually no danger involved in the application of electrical stimulation, providing that the equipment is well designed and constructed. Furthermore, the intensity of the electrical shock can be kept at a minimum as was done by McGuire and Valiance. Unlike drug treatment, electrical stimulation does not give rise to unpleasant sideeffects. Electrical stimulation also avoids the possibility (encountered in some drug treatments) of inducing an unwanted suppression of the developing conditioned response by depressing central nervous activity. The hypnotic effects produced by the administration of the commonly-used, nausea-producing drug, apomorphine, can be entirely avoided. Electrical techniques are likely to have a wider range of application than chemical methods. For example, it would be impossible to use chemical aversion in the treatment of writer’s cramp. Some indication of the potential usefulness of electrical aversion methods can be obtained from a consideration of the results which have been reported to date. Most of this work, which is summarized in Table 1, has been carried out during the past two years. Methods which involve the use of electric shocks in an incidental manner (e.g. Wolpe’s anxiety-relief technique, 1958) are not included. Crosby’s (1950) use of electrical stimulation in the treatment of enuresis is excluded because auditory stimulation provides a satisfactory, non-chemical alternative (Jones, 1960; Lovibond, 1963). Although the techniques which are included in the Table differ quite considerably, they all involve the use of electric shocks as the primary aversive stimulus. Assessment of their comparative therapeutic efficacy would, of course, be premature at this stage. The practical requirements of each method can be obtained in the original articles. The simplest method is described by McGuire and Valiance (1964); Feldman and MacCullough’s (1964) method is strongly inlluenced by experimental techniques and theoretical considerations. Valuable theoretical and experimental information is provided by Church (1963), Solomon and Wynne (1954), Turner and Solomon (1962), Solomon and Brush (1956), Estes (1944) and Kimble (1961). It will be obvious from an inspection of Table 1 that the information which is now available can only be regarded as suggestive. A definitive assessment of the efficacy of electrical aversion techniques will only be possible when controlled trials (with adequate
McGuire & Valiance (1964)
Thorpe et al. (1964)
Transvestism
Transvestism
Transvestism
__.____
Thorpe et al. (1964)
Homosexuality
Blakemore ei nl. (1963)
.___ ~.~__-.---.. ~_-..__~_-..--~
.-__-.-.-_-.-~-.-.
___.- _.._-
_... -._~_---_-
-...
-
0
1
1
1
1
1
2
2
____ __._ .-
2
3
.--..-... .__-
0 -___-
1
.---- ------.
0
0
0
1
0
0
0
0
1
0
1 year
._-._
-
-
-
-
2
0
0
Brief, temporary relapse
-
-
_
-
__ ________
1-14 months
1 month +
4 months
No. relapses
Follow-up Duration
._-.. _~_______
- .._-._.___i_
.__~~ 1
0
-___
5
11
0
None
16
1
Partial
3
0
Marked
(Improvement)
6
1
No. cases
_-- _.-----
Thorpe, Schmidt & Caste11 (1963)
Thorpe & Schmidt (1963) _- ----____
.-__ -
Homosexuality
Homosexuality _-____-
-.--
Feldman & McCullough (196.5)
Homosexuality
-...-. __~__~___
McGuire & Valiance (1964)
Homosexuaiity
__.__~_
Max (1935)
Author/s
Homosexuality
-
Disorder
Outcome
TABLE 1. CASESTREATED WELECTRICALAVERSIONTHERAPY
$ 5
Tz
v”
?
Meyer & Crisp (1964)
Wolpe (1965)
Drug-addiction
--___
Overeating (obesity)
--
Thorpe et al. (1964)
_.--
Thorpe et al. (1964)
_---___
Overeating (obesity)
-~-
Obsess. compulsive
--~
McGuire & Valiance (1964)
Obsess. compulsive
~~-___-.~-----
McGuire & Valiance (1964)
~.____.
McGuire & Valiance (1964)
-__. .__---_--~--.----
McGuire & Valiance (1964)
-.
Alcoholism
Sexual perversions (excl. homosexuality and transvestism) -_--__~___-_.
---.--_..--_-.~I__.._
Fetishism
___.___~
Author/s
Rachman (1961)
__~~______._~_
Transvestism and Fetishism ~..--_--
-____
Disorder
---
I
8
1
0
0
1
0
0
T
^ __-__i__
-- .-
_ .--__.
0
Marked
Outcome
2
1
_I_-~
1
5
7
8
1
1
No. cases
TABLE I-continued
1
1
0
0
1
0
1
_.___.
-
-
-
-
1%years
3 months
0
_-. .-._---~~--.
-
1
1
-
1
0
-__
.---
-
-
_.-
___~__.__.._-~
--
No. relapses
Follow-up Duration
_^._.______._.- .-_-._----
1
1
5
0
0
None
______l__
Partial
(Improvement)
57
1
3
3
114
Beech (1960)
McGuire & Valiance (1964)
Writer’s Cramp
Writer’s Cramp
Tot&
--;-\
29
39
Liversedge & Sylvester (1960)
Writer’s Cramp
I_~
7
Marked
Outcome
10
No. cases
McCuire & Vallance (1964)
Author/s
Smoking
Disorder
TABLEl-continued
-
1
0
Partial
32
0
1
10
3
None
(Improvement)
-
1 1-12 months
-
5 4% years
.--
.~-
No. relapses
Duration
Follow-up
AVERSION
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follow-ups) have been carried out. It is to be hoped that the preliminary investigations reviewed here will promote further research and eventually lead to proper field trials. The fact that these early investigations have yielded improvements in difficult disorders (such as transvestism and homosexuality) is, of course. very encouraging. It will be some time before the disadvantages of the electrical method become apparent. It is worth drawing attention, however, even at this early stage to some of the practical difficulties which have been encountered in chemical aversion treatment and which may be expected to arise when the electrical method is fully developed. As we have already mentioned, the administration of aversive stimuli in laboratory experiments can give rise to aggressive behaviour. In clinical practice, aggressiveness, negativism and hostility have already been encountered during the conduct of chemical aversion treatment. Secondly, there can be little doubt that most people have a fear of electrical shocks and that the method may prove to be exceedingly unpopular with some patients. The anxiety level of many patients can certainly be expected to increase with the introduction of electrical stimulation and this may in turn interfere with the development of conditioned avoidance reactions, An example of this type of difficulty is reported by Beech (1960) who found that some patients reacted unfavourably to the administration of the electric shocks involved in the treatment of does prove to be a stumbling writer’s cramp. If the presence of a high degree of emotionality block in the application of electrical aversion treatment, the experimental work of Turner and Solomon (1962) may be of some assistance. They concluded, on the basis of an interesting series of experiments on avoidance conditioning in human subjects, that the conditioning of “. . . a highly emotional subject will proceed most rapidly if we start off with a short CS-UCS interval and then lengthen it, at the same time that we start with an intense UCS level then lower it to produce longer latency escape responses. When these procedures are The possible application of these combined, we should be able to produce rapid learning”. findings is discussed in Eysenck and Rachman (1965). A major problem which looms in the background is that of relapses. The experience with aversion treatment so far has shown that a large number of relapses can occur when these methods are used. Here again techniques will have to be developed to overcome the relapses or to prevent their occurrence. Two possible methods which might be used, intermittent reinforcement and booster treatments, have already been mentioned. A third possibility is the use of stimulant drugs during the progress of electrical aversion treatment as there is experimental evidence that these drugs facilitate the acquisition of conditioned responses (Eysenck, 1960). Although the present paper presents comparisons of the two major methods of aversion treatment there are, of course, other possibilities which might be contemplated. These include unpleasant auditory stimulation and other forms of aversive stimulation (Eysenck and Rachman, 1965). The technique developed by Sanderson, Campbell and Laverty (1964) which employs a curare-like drug seems to the present author to be ill-advised. In this method the patient is given an injection of the drug which brings about total parafysis for between 30 and 150 sec. During this period, breathing ceases and there can be no doubt that it is an altogether terrifying experience. Although Sanderson et al. have reported a degree of success in treating alcoholics with this method, the present author has theoretical and ethical reservations about the technique. These objections are underlined by the fact that Sanderson, Campbell and Laverty apparently did not give all of their potential patients a frank explanation of the nature of the treatment which they were to undergo, There are good reasons for recommending complete candour in describing the nature of the treatment which is being offered to patients in all circumstances; in this case the reasons are more
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compelling because the experience is particularly harrowing. Moreover, as has been argued in the present paper there are good grounds for optimism about the value of electrical aversion treatment, even when mildly unpleasant stimuli are employed. REFERENCES BECKERW. C. and MATTESON H. 1-I. (1961) GSR conditioning,
auxiety and extraversion.
J. abnorm. (sot.)
Psychol. 62, 427-430.
BEECH R. (1960) The symptomatic treatment of writer’s cramp, in ~ehffvjour Therapy tmd the Neuroses (Ed. Eysenck, H. J.). Pergamon Press Oxford. BLA~EMOREC. B. ef al. (1963) Appli~tion of faradic aversion conditioning in a case of transvestism, Behav. Res. Ther. 1,26-35. CHURCHR. (1963) The varied effects of punishment, Psycho/. Rev. 70,369-402, CROSBYN. D. (1950) Essential enuresis. Med. J. Amt. 2, 533-543. ESTERW. (1944) An experimental study of punishment. Psychoi. Monogr. 57, No. 263. EYSENCKH. J. (Ed.) (1960) Behaviour Therapy and the Neuroses. Pergamon Press, Oxford. EYSENCKH. J. and RACHMANS. (I 965) Calrses and Cures of Neurosis. Routledge and Kegan Paul, London. FELDMANM. P. and MACCULLOUGHM. (1965) The application of anticipatory avoidance conditioning to the treatment of homosexuality. Behav. Res and Ther. 2, 165-184. FRANKSC. M. (1958) Alcohol, alcoholism and conditioning. J. menf. Sci. 104, 14-33. Reprinted in 1960 in Eysenck’s (Ed) Behaviour Therapy and the Neuroses. Pergamon Press, Oxford. FRANKSC. M. (1963) Behaviour therapy, the principles of conditioning and the treatment of the alcoholic. Quart. J. Stud. Alcohol 24,51 l-529.
JONES H. G. (1960) The behavioural treatment of enuresis nocturna. In Behaviour Therapy and the ,Neuroses (Ed. H. J. Eysenck). Pergamon Press, Oxford. KIMBLEG. (1961) Condjtjoning and Learning (revised ed.). Hilgard and Marquis. Methuen, London. LEMEREF. and VOEGTLINW. (1950) An evaluation of the aversion treatment of alcoholism. Quart. J. Stud. Alcohol 11,199-204. LIVERSEDGE L. and SYLVESTER J. (1960) Conditioning techniques in the treatment of writer’s cramp, in Behaviour Therapy and the Neuroses (Ed. H. J. Eysenck). Pergamon Press, Oxford. L~VIBOND S. H. (1963) Intermittent reinforcement in behaviour therapy. Behav. Res. Ther. 1, 127-132. LYNNR. and EYSENCKH. J. (1961) Tolerance for pain, extraversion and neuroticism. Percept. Mot. Skills 12, 161-162. MARTINB. (1963) Reward and punishment associated with the same goal response. Psychol. Bull. 60, 441-451. MAX L. (1935) Breaking a homosexual fixation by the conditioned reflex technique. Psychol. BUN. 32,134. MCGUIRE R. J. and VALLANCEM. (1964) Aversion therapy bv electric shock: a simnle techniaue. Brit. Med. f. 1,151-152. MEYER V. and CRISP A. H. (1964) Aversion therapy in two cases of obesity. Behuv. Res. Ther. 2,143-147. MILLERE., DVORAKB. and TURNERD. (1964) A method of creating aversion to alcohol by reflex conditioning in a group setting, in Conditioning Techniques in Cltnicai Practice and Research (Ed. C. M. Franks). Springer, New York. MORGENS~RNF., PEARCEJ. and DAVIESB. (1963) The application of aversion therapy to transvestism. Paper read at Reading Conference of British Psychological Society. F~SER E. (1960) Der Figurale After-effect als Persoenlichkeitsmerkat. XVIth International Congress of Psychology, Bonn. RACHMANS. (1961) Sexual disorders and behaviour therapy. Amer. J. Psych&. 118,235-240. RAYMOND M. (1964) The treatment of addiction by aversion conditioning with apomorphine. Behav. Res. Ther. 1, 287-292. RAYMOND M. J. (1956) Case of fetishism treated by aversion therapy. &it. Med. J. 2, 854-856. SANDER~~NR., CAMPBELLD. and LAVERTYS. (1964) An investigation of a new aversive conditioning technique for alcoholism, in Conditioning Techniques in Clinical Practice and Research (Ed. C. M. Franks). Springer, New York. SOLOMON R. and BRUSHE. (1956) Experimentally derived conceptions of anxiety and aversion, in Nebraska Symposium on Motivation (Ed. M. R. Jones). University Nebraska Press, Nebraska. SOLCI&O~~ R. L. and WYNNE L. (1954) Traumatic avoidanceieaming: the principles of anxiety conservation and partial irreversibility. Psycho!. Rev. 61,353-385. TKOWE 3. G. and SCHMIDTE. (1964) Therapeutic failure in a case of aversion therapy. Behav. Res. Ther. 1,293-296. THORPE J., SCHMIDT E. and CASTELLD. (1964) A comparison of positive and negative (aversive) conditioning in the treatment of homosexuality. Behav. Res. Ther. 1,357-362.
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THORPE J. G., SCHMIDT E., BROWN P. and CASTELL D. (1964) Aversion relief therapy: A new method for general application. Behav. Res. Ther. 1, 71-82. TURNER L. and SOLOMON R. L. (1962) Human traumatic avoidance learning. Psycho/. Monogr. 76, No. 40. VOEGTLIN W. and LEMERE F. (1942) The treatment of alcohol addiction. Quart. J. Stud. AIcohol2,717-803. WOLPE J. (1965) Conditioned inhibition of craving in drug addiction. Behav. Res. Ther. (in press).
CHEMICAL
OR ELECTRICAL?
S. RACHMAN Institute of Psychiatry,Universityof London (Received 28 December 1964)
AFTERa period of considerable activity during the forties,* research workers appeared to lose interest in the therapeutic possibilities of aversion conditioning. The resurgence of interest in aversion therapy (in Britain at least) can partly be attributed to the publication of Raymond’s (1956) account of treatment of a fetishist by apomorphine conditioning. The response to this paper was, of course, enhanced by the growth of behaviour therapy and in the past few years many successes with aversion treatment have been reported (see reviews by Rachman, 1961; Franks, 1960, 1963; Eysenck and Rachman, 1965). Anyone who contemplates using this form of treatment must first make a decision about the type of noxious stimulus which he is going to employ. In view of the considerable and widespread interest in the practical and theoretical aspects of aversion treatment it is opportune to consider the choice available to therapists at the present time. To date most of the cases reported in the literature have been treated by chemical aversion methods but there are sound reasons for believing that electrical methods may be preferable (Eysenck, 1960; Rachman, 1961). The purpose of this paper is to consider the advantages and disadvantages of the chemical and electrical methods and to draw attention to the possible superiority of the electrical method. Aversion treatment, particularly chemical aversion, can be an unpleasant and arduous form of therapy and this fact, coupled with the often equivocal results obtained in the treatment of alcoholics, probably contributed to its decline in popularity. Franks (1960, 1963) has already drawn attention to the poor quality of much of the early work on aversion treatment of alcoholics. “. . . Unfortunately, not all modern practice is sound. . . For example, some clinicians advocate giving the alcohol after the patient reaches the height of nausea. This of course, is backward conditioning (since the unconditioned stimulus of the apomorphine or the emetine is preceeding the conditioned stimulus of the alcohol) and backward conditioning, if it occurs at all, is at best very tenuous, . . .” (Franks, 1963). In any conditioning situation, the time intervals which elapse between the presentation of the various stimuli and the response are of considerable importance and some aversion therapists appear to have been ignorant of this fact or tended to ignore it. Franks writes that “. . . under such circumstances, it is hardly surprising that reports of evaluation studies range from virtually zero success to 100 per cent success”. The choice of nausea-producing drug has also given rise to difficulty. Some of the drugs which have been used to produce nausea also act as central depressants. This type of drug would interfere with the acquisition of the conditioned response. There is, furthermore, * Miller et aI. (1964) have traced 169 references to conditioning procedures in the literature OD
alcoholism.
289
290
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some confusion about the nature of the particular response which one is attempting to attach to the sight, smell and taste of the alcohol. Tn some of the earlier studies therapists stressed the action of vomiting rather than the feeling of nausea. As Raymond (I 964) has shown, however, the action ofvomiting is not the importantevent-it is the feeling of nausea which influences the acquisition of an avoidance reaction to alcohol. The failure to distinguish between the feeling of nausea and the actual vomiting is a prominent feature of the majority of reports of chemical aversion treatment and this confusion increases the difficulty of assessing the effectiveness of numerous series of case reports. The problems involved in chemical techniques of aversion conditioning are multiplied by the existence of individual differences in reactivity to the various nausea-producing drugs. People differ in the speed and extent of their reactions to the various drugs and, furthermore, the same person may react differently to the same quantity of drug on different days or even at different times on the same day. Individual differences in reactivity, therefore, make the planning of a carefully controlled form of conditioning treatment extremely awkward, The use of chemical noxious stimuli also precludes the possibility of making accurate measurements of the unconditioned and conditioned responses which are being elicited. While it is possible, of course, to obtain measurements of reaction latency, it has proved extremely difficult, if not impossible, to obtain measures of magnitude of the responses produced. Because of the arduous, complicated and unpleasant nature of the chemical aversion conditioning sessions, it is impractical to provide frequent repetitions of the association between the conditioned stimulus and the unconditioned stimulus. The nun~ber of conditioningpresentations and the number of sessions which can be provided are, therefore, inherently restricted. These restrictions not only increase the duration of the treatment period, but they also limit the number of conditioning trials which can be carried out. The treatment is unpleasant, not only for the patient, but also for the therapist and the nursing staff. It is not uncommon for attendants to object to participating in this form of treatment and there can be no doubt that it arouses antagonism in some members of the hospital staff. Complaints about the method being unaesthetic and even harrowing are not entirely without justification-it is certainly a method which does not lend itself to popularity. The unpleasant nature of this treatment also makes it rather difficult to arrange for patients to be treated on an out-patient basis. There is also some clinical evidence to suggest that chemical aversion treatment brings about increased aggressiveness and hostiIity on the part of the patient (~orgenstern and Pearce, 1963). It should be pointed out, however, that some of these reactions to chemical aversion therapy are not entirely surprising; it has been observed experimentally that the administration of aversive stimulation of various kinds can give rise to an increase in aggressive behaviour (Martin, 1963). It may, indeed, prove necessary to develop special methods for managing the increased aggression, if and when it occurs. A second difficulty which may be anticipated in most forms of aversion therapy concerns the anxiety of the patient. It has been suggested (Eysenek and Rachman, 1965) that there is a possibility that highly anxious patients may respond unfavourably to aversion treatment. Finally, it should be mentioned that some of the drugs which have been used in chemical aversion treatment have unpleasant side-effects and can be dangerous, Certainly, chemical aversion cannot be used for the trea~ent of patients with gastric ailments or cardiac complaints. Despite the difliculties enumerated above and the indifferent quality of a great deal of the work on chemical aversion treatment, some remarkable successes have, nevertheless, been achieved. Voegtlin and his colleagues (Voegtlin and Lemere, 1942; Lemere and
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Voegtlin, 1950) obtained creditable results in their treatment of over 4000 alcoholic patients. Raymond (1964) has reported successes in treating alcoholics, sexual perverts and drug addicts; Morgenstern and Pearce (I 963) have had encouraging results in their treatment of transvestites and so forth. Despite the fact that this method is often marred by a high relapse rate, there is no escaping the fact that many otherwise untreatable patients have obtained substantial benefits (and in many cases cures) from chemical aversion treatment. It should also be emphasized that the types of disorders that have yielded successes are precisely those kinds of abnormalities which are ordinarily resistant to change. Certainly, until the advent of aversion therapy there was little that could be offered to patients with sexual perversions such as fetishism, transvestism and the like. One of the earliest reports of an electrical aversion method was a brief account given by Max (1935) of the elimination of a homosexual fixation by the administration of brief electric shocks. This suggestive paper was apparently ignored however. In view of the extensive use made of electrical stimulation in avoidance conditioning experiments, it is curious that therapists have neglected to apply these findings until fairly recently. The bulk of the available laboratory evidence on avoidance conditioning (and there is a considerable amount of such evidence) concerns experiments in which the aversive stimulus was an electric shock. This is the first, and potentially the most important, of all the advantages offered by electrical methods of aversion treatment. Over the past few decades psychologists have accumulated a wealth of detailed information about the effects of electrical stimulation on behaviour, and while it is true that there are many problems which have yet to be resolved, there is also little doubt that the information which is already available can help tremendously in the design and conduct of aversion treatment. An encouraging start in this direction has already been made by Feldman and MacCullough (1965) who have demonstrated in a very clear manner how it is possible to construct a therapeutic programme from fundamental findings in the field of aversive conditioning. An importanttheoretical contribution to the understanding of the effects of aversive stimulus on behaviour was recently made by Church (1963). Summing up the position, Church writes : “In comparison with a procedure involving no aversive stimulation, the effects of punishment are varied. If punishment reinstates a condition of original training, or it elicits a response similar to the act being punished, then the procedure may produce response facilitation. Otherwise, punishment will produce response suppression”. If the aversive stimulation is not contingent upon the discriminative stimuli, “ , , . the effect of punishment is simple . . . it always produces suppression”. The effectiveness of aversive electrical stimulation depends on numerous factors, such as the intensity of the stimulus, the amount and kind of previous training, the person’s drive level, time relations between the administration of the stimulus and the occurrence of the response. Information concerning all of these (and other) relevant variables can be found in the literature on experimental psychology and employed in the design of effectiveness of aversion treatment (see the discussion in Eysenck and Rachman, 1965). Electrical stimulation can be precisely controlled. The therapist is in a position to administer a discrete stimulus of precise intensity for a precise duration of time at precisely the required moment. In this respect electrical aversion stimulation is clearly superior to chemical aversion. Each of these variables can be manipulated according to requirements and the entire treatment process becomes considerably more flexible. The greater control which is possible with electrical stimulation should ensure more effective treatment, closer definition of the treatment process and increased theoretical clarity.
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Chemical techniques do not provide much scope for ~nodifi~ations which might be introduced on the basis of the patient’s personality. Individlia~ differences tend to be blotted out because the chemical aversion procedures cannot be ~llanipulated with precision. For example, the observation that extraverts have a greater toferance for pain than introverts (Lynn and Eysenck. 1961) could not be used to advantage. Lynn and Eysenck obtained a correlation of 0.69 between extraversion and pain tolerance in a group of 30 students and Poser (1960) reported a correlation of 0.53. Other relevant reports are quoted by Lynn and Eysenck and these, coupled with the suggestion that extraverts can tolerate more intense electric shocks than introverts (Becker, 1961), may produce useful modifications of the electrical method. Certainly, individual differences in reactivity to, and tolerance for, electric shocks can be incorporated in electrical aversion treatment. When the relationships between personality and these variables have been worked out in greater detail, it should be possible to provide treatl~~etlt schedules which will be designed to meet the needs of the individuai patient. In addition, the increased therapeutic control provided by electrical stimulation permits the therapist to make accurate measurements of the progress of treatment. For example, Rachman (1961) gives a brief account of the technique of mcasuremcnt which he used in tracing the effectiveness of electrical stimulation on the sexual images of a fetishist. It was found that as the number of associations between fetishistic-transvestite impulses and electrical stimulation was increased, the patient found it increasingly difficult to conjure up the images. The duration of the images showed a concomitant decrease. It was found possible to make exact measurements of both latency and duration of the response (image). This enabled the therapist to plot the course and progress of the treatment. Similar measurements have been reported by McGuire and Vatlance (1964) and by Feldman and Ma~C~~lfoug~~(1964f. ~eas~tren~ents of the patient’s reactions at each stage of the treatment are valuable in their own right and also because of the information which they provide about the relationship between imagery and action. With the accumulation of research on this topic it should be possible to work out in some detail the relationship between, say, images of sexual perversions and the real act. Tn particular it would be very interesting to see whether or not the reductions in frequency and duration of the images are accompanied by similar reductions in the patient’s overt activity and, if they are, whether there is any time lag in the transfer from imagery to actual behaviour. Unlike chemical aversion treatment, electrical stimulation permits frequent repetitions of the association between the unwanted behaviour and the noxious stimulus. it is perfectly feasible to present a large number of trials to the patient during one session and also to provide for nunlerous conditioning sessions within the same day. This should enable treatment to progress more quickly. It is also feasibIe to construct portable apparatus for the delivery of the shocks and this allows treatment to be carried out on an out-patient basis. In some cases the patient can even administer the noxious stimulus to himself, if and when the necessity arises. A recent example of self-administered electrical stimulation was reported by Wolpe (1965). In this report, he described the partially successful treatment of a patient who was suffering from a drug-addiction. It was possible to bring about a temporary suppression of drug craving by getting the patient to administer the electric shock to himself whenever the craving arose. The apparatus which was used in this case was that described by McCuire and Valiance (1964).
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Experience with chemical aversion methods leads us to expect a rather high relapse rate in aversion treatment generally. A similar situation has, of course, been encountered in the conditioning treatment of enuresis (Gwynne Jones, 1960). In an attempt to obtain greater stability of nocturnal continence in the patients treated by the bell-and-pad method, Lovibond (1963) adniinistered his conditioning programme on an intermittent reinforcement schedule. Although it is not yet possible to reach a firm conclusion about the long term effectiveness of the intermittent reinforcement schedule used in this type of disorder, there are very strong grounds for believing that intermittent reinforcement schedules may indeed provide a key to the reduction of relapse rate in aversion treatment. Certainly, intermittent reinforcement is very much simpler to programme if one employs an electrical stimulus rather than drugs. Another possible technique for reducing the relapse rate is the use of booster treatments and these, too, are more feasible with the electrical method, especially as it is possible to construct portable apparatus. This might permit the patient to administer the booster treatments to himself when necessary. Another difficulty which can be overcome by the substitution of electrical for chemical aversion methods concerns the staff problems mentioned earlier. Electrical treatment does not require more than one therapist to be present and it is considerably less arduous and cumbersome (see McGuire and Valiance, for example). With the possible exception of patients with cardiac complaints there is virtually no danger involved in the application of electrical stimulation, providing that the equipment is well designed and constructed. Furthermore, the intensity of the electrical shock can be kept at a minimum as was done by McGuire and Valiance. Unlike drug treatment, electrical stimulation does not give rise to unpleasant sideeffects. Electrical stimulation also avoids the possibility (encountered in some drug treatments) of inducing an unwanted suppression of the developing conditioned response by depressing central nervous activity. The hypnotic effects produced by the administration of the commonly-used, nausea-producing drug, apomorphine, can be entirely avoided. Electrical techniques are likely to have a wider range of application than chemical methods. For example, it would be impossible to use chemical aversion in the treatment of writer’s cramp. Some indication of the potential usefulness of electrical aversion methods can be obtained from a consideration of the results which have been reported to date. Most of this work, which is summarized in Table 1, has been carried out during the past two years. Methods which involve the use of electric shocks in an incidental manner (e.g. Wolpe’s anxiety-relief technique, 1958) are not included. Crosby’s (1950) use of electrical stimulation in the treatment of enuresis is excluded because auditory stimulation provides a satisfactory, non-chemical alternative (Jones, 1960; Lovibond, 1963). Although the techniques which are included in the Table differ quite considerably, they all involve the use of electric shocks as the primary aversive stimulus. Assessment of their comparative therapeutic efficacy would, of course, be premature at this stage. The practical requirements of each method can be obtained in the original articles. The simplest method is described by McGuire and Valiance (1964); Feldman and MacCullough’s (1964) method is strongly inlluenced by experimental techniques and theoretical considerations. Valuable theoretical and experimental information is provided by Church (1963), Solomon and Wynne (1954), Turner and Solomon (1962), Solomon and Brush (1956), Estes (1944) and Kimble (1961). It will be obvious from an inspection of Table 1 that the information which is now available can only be regarded as suggestive. A definitive assessment of the efficacy of electrical aversion techniques will only be possible when controlled trials (with adequate
McGuire & Valiance (1964)
Thorpe et al. (1964)
Transvestism
Transvestism
Transvestism
__.____
Thorpe et al. (1964)
Homosexuality
Blakemore ei nl. (1963)
.___ ~.~__-.---.. ~_-..__~_-..--~
.-__-.-.-_-.-~-.-.
___.- _.._-
_... -._~_---_-
-...
-
0
1
1
1
1
1
2
2
____ __._ .-
2
3
.--..-... .__-
0 -___-
1
.---- ------.
0
0
0
1
0
0
0
0
1
0
1 year
._-._
-
-
-
-
2
0
0
Brief, temporary relapse
-
-
_
-
__ ________
1-14 months
1 month +
4 months
No. relapses
Follow-up Duration
._-.. _~_______
- .._-._.___i_
.__~~ 1
0
-___
5
11
0
None
16
1
Partial
3
0
Marked
(Improvement)
6
1
No. cases
_-- _.-----
Thorpe, Schmidt & Caste11 (1963)
Thorpe & Schmidt (1963) _- ----____
.-__ -
Homosexuality
Homosexuality _-____-
-.--
Feldman & McCullough (196.5)
Homosexuality
-...-. __~__~___
McGuire & Valiance (1964)
Homosexuaiity
__.__~_
Max (1935)
Author/s
Homosexuality
-
Disorder
Outcome
TABLE 1. CASESTREATED WELECTRICALAVERSIONTHERAPY
$ 5
Tz
v”
?
Meyer & Crisp (1964)
Wolpe (1965)
Drug-addiction
--___
Overeating (obesity)
--
Thorpe et al. (1964)
_.--
Thorpe et al. (1964)
_---___
Overeating (obesity)
-~-
Obsess. compulsive
--~
McGuire & Valiance (1964)
Obsess. compulsive
~~-___-.~-----
McGuire & Valiance (1964)
~.____.
McGuire & Valiance (1964)
-__. .__---_--~--.----
McGuire & Valiance (1964)
-.
Alcoholism
Sexual perversions (excl. homosexuality and transvestism) -_--__~___-_.
---.--_..--_-.~I__.._
Fetishism
___.___~
Author/s
Rachman (1961)
__~~______._~_
Transvestism and Fetishism ~..--_--
-____
Disorder
---
I
8
1
0
0
1
0
0
T
^ __-__i__
-- .-
_ .--__.
0
Marked
Outcome
2
1
_I_-~
1
5
7
8
1
1
No. cases
TABLE I-continued
1
1
0
0
1
0
1
_.___.
-
-
-
-
1%years
3 months
0
_-. .-._---~~--.
-
1
1
-
1
0
-__
.---
-
-
_.-
___~__.__.._-~
--
No. relapses
Follow-up Duration
_^._.______._.- .-_-._----
1
1
5
0
0
None
______l__
Partial
(Improvement)
57
1
3
3
114
Beech (1960)
McGuire & Valiance (1964)
Writer’s Cramp
Writer’s Cramp
Tot&
--;-\
29
39
Liversedge & Sylvester (1960)
Writer’s Cramp
I_~
7
Marked
Outcome
10
No. cases
McCuire & Vallance (1964)
Author/s
Smoking
Disorder
TABLEl-continued
-
1
0
Partial
32
0
1
10
3
None
(Improvement)
-
1 1-12 months
-
5 4% years
.--
.~-
No. relapses
Duration
Follow-up
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follow-ups) have been carried out. It is to be hoped that the preliminary investigations reviewed here will promote further research and eventually lead to proper field trials. The fact that these early investigations have yielded improvements in difficult disorders (such as transvestism and homosexuality) is, of course. very encouraging. It will be some time before the disadvantages of the electrical method become apparent. It is worth drawing attention, however, even at this early stage to some of the practical difficulties which have been encountered in chemical aversion treatment and which may be expected to arise when the electrical method is fully developed. As we have already mentioned, the administration of aversive stimuli in laboratory experiments can give rise to aggressive behaviour. In clinical practice, aggressiveness, negativism and hostility have already been encountered during the conduct of chemical aversion treatment. Secondly, there can be little doubt that most people have a fear of electrical shocks and that the method may prove to be exceedingly unpopular with some patients. The anxiety level of many patients can certainly be expected to increase with the introduction of electrical stimulation and this may in turn interfere with the development of conditioned avoidance reactions, An example of this type of difficulty is reported by Beech (1960) who found that some patients reacted unfavourably to the administration of the electric shocks involved in the treatment of does prove to be a stumbling writer’s cramp. If the presence of a high degree of emotionality block in the application of electrical aversion treatment, the experimental work of Turner and Solomon (1962) may be of some assistance. They concluded, on the basis of an interesting series of experiments on avoidance conditioning in human subjects, that the conditioning of “. . . a highly emotional subject will proceed most rapidly if we start off with a short CS-UCS interval and then lengthen it, at the same time that we start with an intense UCS level then lower it to produce longer latency escape responses. When these procedures are The possible application of these combined, we should be able to produce rapid learning”. findings is discussed in Eysenck and Rachman (1965). A major problem which looms in the background is that of relapses. The experience with aversion treatment so far has shown that a large number of relapses can occur when these methods are used. Here again techniques will have to be developed to overcome the relapses or to prevent their occurrence. Two possible methods which might be used, intermittent reinforcement and booster treatments, have already been mentioned. A third possibility is the use of stimulant drugs during the progress of electrical aversion treatment as there is experimental evidence that these drugs facilitate the acquisition of conditioned responses (Eysenck, 1960). Although the present paper presents comparisons of the two major methods of aversion treatment there are, of course, other possibilities which might be contemplated. These include unpleasant auditory stimulation and other forms of aversive stimulation (Eysenck and Rachman, 1965). The technique developed by Sanderson, Campbell and Laverty (1964) which employs a curare-like drug seems to the present author to be ill-advised. In this method the patient is given an injection of the drug which brings about total parafysis for between 30 and 150 sec. During this period, breathing ceases and there can be no doubt that it is an altogether terrifying experience. Although Sanderson et al. have reported a degree of success in treating alcoholics with this method, the present author has theoretical and ethical reservations about the technique. These objections are underlined by the fact that Sanderson, Campbell and Laverty apparently did not give all of their potential patients a frank explanation of the nature of the treatment which they were to undergo, There are good reasons for recommending complete candour in describing the nature of the treatment which is being offered to patients in all circumstances; in this case the reasons are more
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compelling because the experience is particularly harrowing. Moreover, as has been argued in the present paper there are good grounds for optimism about the value of electrical aversion treatment, even when mildly unpleasant stimuli are employed. REFERENCES BECKERW. C. and MATTESON H. 1-I. (1961) GSR conditioning,
auxiety and extraversion.
J. abnorm. (sot.)
Psychol. 62, 427-430.
BEECH R. (1960) The symptomatic treatment of writer’s cramp, in ~ehffvjour Therapy tmd the Neuroses (Ed. Eysenck, H. J.). Pergamon Press Oxford. BLA~EMOREC. B. ef al. (1963) Appli~tion of faradic aversion conditioning in a case of transvestism, Behav. Res. Ther. 1,26-35. CHURCHR. (1963) The varied effects of punishment, Psycho/. Rev. 70,369-402, CROSBYN. D. (1950) Essential enuresis. Med. J. Amt. 2, 533-543. ESTERW. (1944) An experimental study of punishment. Psychoi. Monogr. 57, No. 263. EYSENCKH. J. (Ed.) (1960) Behaviour Therapy and the Neuroses. Pergamon Press, Oxford. EYSENCKH. J. and RACHMANS. (I 965) Calrses and Cures of Neurosis. Routledge and Kegan Paul, London. FELDMANM. P. and MACCULLOUGHM. (1965) The application of anticipatory avoidance conditioning to the treatment of homosexuality. Behav. Res and Ther. 2, 165-184. FRANKSC. M. (1958) Alcohol, alcoholism and conditioning. J. menf. Sci. 104, 14-33. Reprinted in 1960 in Eysenck’s (Ed) Behaviour Therapy and the Neuroses. Pergamon Press, Oxford. FRANKSC. M. (1963) Behaviour therapy, the principles of conditioning and the treatment of the alcoholic. Quart. J. Stud. Alcohol 24,51 l-529.
JONES H. G. (1960) The behavioural treatment of enuresis nocturna. In Behaviour Therapy and the ,Neuroses (Ed. H. J. Eysenck). Pergamon Press, Oxford. KIMBLEG. (1961) Condjtjoning and Learning (revised ed.). Hilgard and Marquis. Methuen, London. LEMEREF. and VOEGTLINW. (1950) An evaluation of the aversion treatment of alcoholism. Quart. J. Stud. Alcohol 11,199-204. LIVERSEDGE L. and SYLVESTER J. (1960) Conditioning techniques in the treatment of writer’s cramp, in Behaviour Therapy and the Neuroses (Ed. H. J. Eysenck). Pergamon Press, Oxford. L~VIBOND S. H. (1963) Intermittent reinforcement in behaviour therapy. Behav. Res. Ther. 1, 127-132. LYNNR. and EYSENCKH. J. (1961) Tolerance for pain, extraversion and neuroticism. Percept. Mot. Skills 12, 161-162. MARTINB. (1963) Reward and punishment associated with the same goal response. Psychol. Bull. 60, 441-451. MAX L. (1935) Breaking a homosexual fixation by the conditioned reflex technique. Psychol. BUN. 32,134. MCGUIRE R. J. and VALLANCEM. (1964) Aversion therapy bv electric shock: a simnle techniaue. Brit. Med. f. 1,151-152. MEYER V. and CRISP A. H. (1964) Aversion therapy in two cases of obesity. Behuv. Res. Ther. 2,143-147. MILLERE., DVORAKB. and TURNERD. (1964) A method of creating aversion to alcohol by reflex conditioning in a group setting, in Conditioning Techniques in Cltnicai Practice and Research (Ed. C. M. Franks). Springer, New York. MORGENS~RNF., PEARCEJ. and DAVIESB. (1963) The application of aversion therapy to transvestism. Paper read at Reading Conference of British Psychological Society. F~SER E. (1960) Der Figurale After-effect als Persoenlichkeitsmerkat. XVIth International Congress of Psychology, Bonn. RACHMANS. (1961) Sexual disorders and behaviour therapy. Amer. J. Psych&. 118,235-240. RAYMOND M. (1964) The treatment of addiction by aversion conditioning with apomorphine. Behav. Res. Ther. 1, 287-292. RAYMOND M. J. (1956) Case of fetishism treated by aversion therapy. &it. Med. J. 2, 854-856. SANDER~~NR., CAMPBELLD. and LAVERTYS. (1964) An investigation of a new aversive conditioning technique for alcoholism, in Conditioning Techniques in Clinical Practice and Research (Ed. C. M. Franks). Springer, New York. SOLOMON R. and BRUSHE. (1956) Experimentally derived conceptions of anxiety and aversion, in Nebraska Symposium on Motivation (Ed. M. R. Jones). University Nebraska Press, Nebraska. SOLCI&O~~ R. L. and WYNNE L. (1954) Traumatic avoidanceieaming: the principles of anxiety conservation and partial irreversibility. Psycho!. Rev. 61,353-385. TKOWE 3. G. and SCHMIDTE. (1964) Therapeutic failure in a case of aversion therapy. Behav. Res. Ther. 1,293-296. THORPE J., SCHMIDT E. and CASTELLD. (1964) A comparison of positive and negative (aversive) conditioning in the treatment of homosexuality. Behav. Res. Ther. 1,357-362.
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THORPE J. G., SCHMIDT E., BROWN P. and CASTELL D. (1964) Aversion relief therapy: A new method for general application. Behav. Res. Ther. 1, 71-82. TURNER L. and SOLOMON R. L. (1962) Human traumatic avoidance learning. Psycho/. Monogr. 76, No. 40. VOEGTLIN W. and LEMERE F. (1942) The treatment of alcohol addiction. Quart. J. Stud. AIcohol2,717-803. WOLPE J. (1965) Conditioned inhibition of craving in drug addiction. Behav. Res. Ther. (in press).