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Cognitions related to anxiety: a pilot study of treatment
Behsv.
Rcs. & Therapy.
1977. Vol. Ii
pp. 503-505.
CASE HISTORIES
Pergamon
Press.
Printed
m Great
Bnta~n
AND SHORTER
COMMUNICATIONS
Cogoitions related to anxiety: a pibt study of treatment* (Received 12 May 1977)
In general, where anxiety appears to have a specific external focus, such as the situations which are avoided by phobic patients, treatment involving systematic exposure to those situations seems to be effective. This is less appropriate, or even impossible, where anxiety is not dependent on any external circumstance, but is described by the patient as occurring at any time or place, either chronically over long periods, or acutely in the form of ‘panic attacks’. These patients with ‘general&d’ anxiety often describe internal cues for anxiety either in the form of thoughts (e.g. worry over a current problem) or somatic (e.g. chest sensations interpreted as possible heart disease). Beck et al. (1974) has suggested that on interview, al1 patients diagnosed as suffering from diffuse or general&d anxiety can report specific ideas or other cognitive cues which are associated with anxiety. These usually concern possible traumatic events, such as illness and death, or social rejection. Clearly Beck has in mind the possibility that these cognitions have the effect of inducing anxiety, although even if the validity of the subjective reports were to be accepted, the problem remains of whether the relationship between mood state and cognitions is causal and if so, in which direction it operates. Obviously a causal relationship may also operate in both directions simultaneously, to form a ‘vicious circle’ in which each exacerbates the other. To establish whether there is a sense in which particular cognitions contribute causally to anxious mood, it would be necessary to find a method of manipulating the type or frequency of cognitions thought to be operating in this way. One obvious possibility is that of ‘thought-stopping’: that is, patients could be taught to identify thoughts which are associated with anxiety and stop them in the usual way (Woipe, 1973, p. 211) e.g. by ‘shouting stop, and substituting an alternative thought. The present study was planned as a pilot experiment to determine (i) if appropriate anxiety related cognitions could be elicited from a series of patients with generalised anxiety, (ii) if the reported frequency of such thoughts could be modified by a thought-stopping technique, and (iii) if any changes in thought frequency were associated with improvements in mood. Clearly there are many ‘non-specific’ features involved in thought-stopping which could also have therapeutic effects on mood. For this reason it was necessary to include an alternative procedure, not directed at reducing thought frequency, but having the same degree of plausibility to patients, and preferably to therapists. The control procedure chosen for this purpose was modelled on desensitisation, in which patients were encouraged to allow the supposedly anxiety-provoking thoughts into their mind and tolerate them, rather than attempt to stop them. In summary, the study employed a relaxation training phase as a base-line, followed by a cross-over design in which the two treatment phases of thought-stopping and ‘cognitive desensitisation’ were given to each patient, in balanced order.
METHOD
Subjects Psychiatric out-patients referred to the University Department of Psychiatry were assessed and accepted into the study if they met the following criteria: the diagnosis was that of general anxiety in the absence of either phobic avoidance or obsessional rituals, they were not receiving any treatment other than maintainance medication which could be held constant, and they agreed to participate in a time-Iimited course of psychological treatment after this had been described to them. A total of 14 such patients were accepted into the study, but one dropped out before treatment started, two did not complete all planned sessions as they felt they were ‘cured’, and results from one were not anaiysed because of beneficial changes in life circumstances during treatment. This left 10 patients in the study, four women and six men.
Treatment took the form of eight weekly sessions, excluding assessment interviews with the screening psychiatrist (P.S) at pre-treatment, post-treatment, and one month follow-up. Before treatment proper began, all patients were handed a booklet in which a general explanatory model of anxiety was described, emphasising the dual role of worry and bodily tension. Instructions were given that treatment took the form of training in self-help techniques; initially muscular relaxation, and subsequently in the two methods of dealing with upsetting or worrying thoughts. They were then asked to list any thoughts which they associated with periods of increased anxiety, and to rate the likelihood of benefit from each of the training components. The booklet was discussed in the first therapy session, and after any questions arising had been dealt with, treatment began with a demonstratjon of simple relaxation exercises for daily practice at home. At this point patients were atso instructed in the use of a diary record of anxious mood and thought frequency, described below. Relaxation training continued in the second and third sessions. following the usual progression employed prior to systematic desensitisation. After this, patients were randomly allocated to thought-stopping first or ‘desensitisation’ first, two weeks being allowed for each. In thought-stopping, patients were instructed to relax for five minutes, and then * This research was supported by a grant from the Medicai Research Council, U.K. 503
504
CASE
HISTORIES
AND
SHORTER
COMMUNICATIONS
to begin concentrating on a designated anxiety thought which was to be signalled as soon as it was clear. At this point the therapist shouted ‘stop’ and instructed the patient to substitute a pre-arranged alternative thought. After this the procedure followed the usual sequence of increasing patient responsibility for terminating the thought without intervention by the therapist, until the induction and termination of thoughts could be performed by the patient alone. Emphasis was placed on daily home practice between sessions, and patients were encouraged to experiment with variations (such as snapping a rubber band round the wrist) to find the most effective way of stopping the designated thought. As well as daily practice sessions, they were also asked to apply the method as appropriate to any spontaneously arising thoughts throughout the day. In ‘cognitive desensitisation’ the procedure applied was identical until the point at which the patient signalled that a thought was clear, at which time they were not instructed to stop it, but instead to tolerate it, and allow it to remain for as long as it seemed clear. When patients became anxious they were encouraged to wait until the anxiety subsided, but if the reaction was excessive, or the patient refused to continue, a less intense form of the anxiety thought was found; that is, a simple hierarchy was constructed. As a rule any anxiety rapidly dissipated and after one to two minutes the patient signalled that the thought had faded. After a brief pause for relaxation, the sequence was then repeated. Equivalent instructions were given for dealing with anxiety thoughts arising between sessions. When crossing over from one treatment to the other, that is on the sixth treatment session, a rationale was given for the change. This took the form of an explanation that the inethod used to date, whether thou~t-stopping or d~sit~ation, would probably prove best in some circumstances, but not ah. For this reason, training would be given in an alternative procedure, and for these next two weeks the patient should concentrate completely on this new method. At the end of the cross-over sequence patients would thus be in a position to choose when to apply each method as appropriate. The final (eighth) session was used to gather reports on the previous weeks progress, and to discuss future self-help practice. Assessmerzt At the screening interview, and at the follow-up interviews, patients were questioned by the independent assessor as to the intensity and frequency of anxiety. Clinical ratings of severity were made in order to assess overali change in clinical anxiety, although this was not ‘blind’ since the assessor knew that patients would have received both treatments, remaining in ignorance only of the order in which they were given. Measures discriminating between the two procedures given in balanced order, thought-stopping and desensitisation, were thus confined to patients self-report. This was available from two sources, a weekly mood male (McNair and Lorr, 1964). and the detailed diary records made by patients every three hours through the day. At 9.OOan-1,12.OOam, 3.oOpm, 6.OOpm and 9.oOpm, they recorded anxious mood on a O-10 scale, estimated time in minutes spent thinking the specified target thoughts in the preceding three hours, and ratings of the effect (if any) which those thoughts had on their mood. RESULTS
All patients entering the study were able to specify some thought content which they associated with anxiety. although some found this much less easy to verbalise than others. In two cases the thoughts were cued by real or anticipated noises (e.g. ‘they are doing it to annoy me’), somatic cues interpreted as indications of possible illness or death figured prominently in five cases, in two cases worries also inciuded pessimistic thoughts about the future in general, and one patient (the least responsive) was preoccupied with the thought that buildings might collapse. In terms of changes in clinically rated anxiety, all patients except this one were rated to have improved in varying degrees, although only two could be judged virtually symptom free on follow-up, and the average rated change was small (0.8 points on the assessors five point anxiety scale, and patients average self-rating of improvement was just above ‘slightly better’). The main analysis of self-report scores during and following each of the two treatment periods intended to modify anxiety-related thoughts, was carried out using analysis of variance on mean scores during the two weeks following intr~uction of each procedure. Analysis of anxiety ratings and effect of thoughts on mood were based on average scores over each two week treatment period, but due to a markedly skewed distribution of estimated time spent engaged in anxiety-associated thoughts, this latter score was re-analysed after conversion to a ratio score by dividing by levels recorded in the first base-line week. In each analysis, however, no significant differences were found. and mean scores were very similar (see Table 1). Analysis of weekly mood estimates from the adjective mood scale was confined to anxiety/tension and depression scores: again no differences were found. A finai series of analyses concerned the comparison of scores during each two week block of cognitive treatment with the equivalent scores averaged over the second and third weeks of treatment, that is, during the latter part of relaxation training. Significant reductions over time were found for all measures except the mean ratings of anxiety derived from the diary ratings made every three hours. Clearly, however, this comparison confounds type of treatment with other changes over time, and only serves to show that the observed changes cannot be attributed to random error of measurement.
Thought duration mm/3 hr ratw to base-bne Thought impact (O-IO) Mood scale ratings anxiety/tension (C-24) depression (%36)
26 0.89 2.0 128 10.6
18.4 0.6 1.7 9.7 6.7
I
17.5 0.62 1.7 9.9 7.9
CASE HISTORIESAND SHORTER COMMUNICATIONS
505
DISCUSSION
The apparently positive aspects of these results; that anxious patients can report repetitive anxiety-associated cognitions (usually concerning possible catastrophic or personally threatening events) and that a self-reported reduction in such cognitions is accompanied by improvement on the mood scale, does not in any way provide evidence of a causal relationship between these thoughts and the complaint of excessive anxiety. Both this, and the tendency for most patients to be rated as clinically improved, can be attributed to non-specific variables such as the expectation of therapeutic change. To provide clearer evidence it would have been necessary to demonstrate that one of the equally plausible procedures given in balanced order had a significantly greater effect in reducing the frequency (or impact) of anxiety-associated cognitions than did the other, and additionally that the more effective procedure also produced correspondingly greater improvements in mood. It was obviously anticipated that thought-stopping should have reduced the time spent engaging in anxious thoughts more than did desensitisation, and the failure to show even this casts considerable doubt on the supposed mechanism of the procedure. In this respect the present negative results are consistent with an earlier failure to show that stopping obsessive thoughts had a better result than stopping neutral thoughts (Stern, Lipsedge and Marks, 1973). As a result of this failure of thought-stopping to have any specific effects, the initial hypothesis of the present study could not be properly tested. In addition to calling into question the basis of thought-stopping as a technique, the study suggests further questions for investigation. Although expectation for change may well be sufficient explanation of the modest clinical improvements seen, this explanation seems less likely in view of the patients responses on a pre-treatment questionnaire asking about likely benefit from four of the treatment components used. On a O-4 scale, mean rating of thought-stopping was highest at 3.7 (between ‘very’ and ‘extremely’ helpful), using a diary was lowest at 1.6 (between ‘slightly’ and ‘moderately’ helpful), with relaxation and desensitisation in between with a mean rating of about three. After treatment, the perceived benefit from all components was approximately equal with a mean rating of two (‘moderately’ helpful), so that all were reduced in perceived helpfulness except for the use of the diary, which showed a slight gain. As described by some of the more articulate and responsive patients, it was as if the upsetting thoughts which had previously been a cue for perseverative alarm or ineffectual efforts to obtain relief, now served as a cue to do something different, although the exact nature of the alternative response was unimportant. The self-monitoring involved in keeping a diary of anxiety-associated thoughts, which at first seemed irksome and unnecessary, was later judged helpful by some patients in reinterpreting the thoughts as behaviour which could be changed, and as a prompt to implement the appropriate technique. It is tempting to speculate that in those cases where the treatment package as a whole was successful, its effectiveness was attributable to a process common to both techniques; for example a sequence in which self-monitoring prompts some alternative activity that distracts attention from the anxiety-evoking content of thoughts, and encourages the idea that they can be changed. To determine if treatments containing such common elements are more effective than those without them must obviously await further research. University Department 0s Psychiafry,
ANDREW MATHEWS* PHYLLIS SHAW
The Wameford Hospital, Oxford, England
* Requests for reprints should be sent to: Professor A. Mathews, Department Hospital Medical School, Cranmer Terrace, Tooting, London SW17, England.
of Psychology, St. Georges
REFERENCES BECK A. T.,LAUDE R. and BOHNERT M. (1974) Ideational components
of anxiety neurosis. Arch. gen. Psychiat.
31, 319-325. MCNAIR D. M. and LORR M. (1964) An analysis of mood in neurotics. J. Abnorm. sot. Psychol. 69, 620-627. STERN R. S., LIPSEDGE M. S. and MARKS I.M. (1973)Obsessive ruminations: a controlled trial of thoughtstopping technique. Behau. Res. and Therapy 11, 659662. WOLPE J. (1973) The Practice of BehoviourTherapy. Pergamon Press, New York.
Rcs. & Therapy.
1977. Vol. Ii
pp. 503-505.
CASE HISTORIES
Pergamon
Press.
Printed
m Great
Bnta~n
AND SHORTER
COMMUNICATIONS
Cogoitions related to anxiety: a pibt study of treatment* (Received 12 May 1977)
In general, where anxiety appears to have a specific external focus, such as the situations which are avoided by phobic patients, treatment involving systematic exposure to those situations seems to be effective. This is less appropriate, or even impossible, where anxiety is not dependent on any external circumstance, but is described by the patient as occurring at any time or place, either chronically over long periods, or acutely in the form of ‘panic attacks’. These patients with ‘general&d’ anxiety often describe internal cues for anxiety either in the form of thoughts (e.g. worry over a current problem) or somatic (e.g. chest sensations interpreted as possible heart disease). Beck et al. (1974) has suggested that on interview, al1 patients diagnosed as suffering from diffuse or general&d anxiety can report specific ideas or other cognitive cues which are associated with anxiety. These usually concern possible traumatic events, such as illness and death, or social rejection. Clearly Beck has in mind the possibility that these cognitions have the effect of inducing anxiety, although even if the validity of the subjective reports were to be accepted, the problem remains of whether the relationship between mood state and cognitions is causal and if so, in which direction it operates. Obviously a causal relationship may also operate in both directions simultaneously, to form a ‘vicious circle’ in which each exacerbates the other. To establish whether there is a sense in which particular cognitions contribute causally to anxious mood, it would be necessary to find a method of manipulating the type or frequency of cognitions thought to be operating in this way. One obvious possibility is that of ‘thought-stopping’: that is, patients could be taught to identify thoughts which are associated with anxiety and stop them in the usual way (Woipe, 1973, p. 211) e.g. by ‘shouting stop, and substituting an alternative thought. The present study was planned as a pilot experiment to determine (i) if appropriate anxiety related cognitions could be elicited from a series of patients with generalised anxiety, (ii) if the reported frequency of such thoughts could be modified by a thought-stopping technique, and (iii) if any changes in thought frequency were associated with improvements in mood. Clearly there are many ‘non-specific’ features involved in thought-stopping which could also have therapeutic effects on mood. For this reason it was necessary to include an alternative procedure, not directed at reducing thought frequency, but having the same degree of plausibility to patients, and preferably to therapists. The control procedure chosen for this purpose was modelled on desensitisation, in which patients were encouraged to allow the supposedly anxiety-provoking thoughts into their mind and tolerate them, rather than attempt to stop them. In summary, the study employed a relaxation training phase as a base-line, followed by a cross-over design in which the two treatment phases of thought-stopping and ‘cognitive desensitisation’ were given to each patient, in balanced order.
METHOD
Subjects Psychiatric out-patients referred to the University Department of Psychiatry were assessed and accepted into the study if they met the following criteria: the diagnosis was that of general anxiety in the absence of either phobic avoidance or obsessional rituals, they were not receiving any treatment other than maintainance medication which could be held constant, and they agreed to participate in a time-Iimited course of psychological treatment after this had been described to them. A total of 14 such patients were accepted into the study, but one dropped out before treatment started, two did not complete all planned sessions as they felt they were ‘cured’, and results from one were not anaiysed because of beneficial changes in life circumstances during treatment. This left 10 patients in the study, four women and six men.
Treatment took the form of eight weekly sessions, excluding assessment interviews with the screening psychiatrist (P.S) at pre-treatment, post-treatment, and one month follow-up. Before treatment proper began, all patients were handed a booklet in which a general explanatory model of anxiety was described, emphasising the dual role of worry and bodily tension. Instructions were given that treatment took the form of training in self-help techniques; initially muscular relaxation, and subsequently in the two methods of dealing with upsetting or worrying thoughts. They were then asked to list any thoughts which they associated with periods of increased anxiety, and to rate the likelihood of benefit from each of the training components. The booklet was discussed in the first therapy session, and after any questions arising had been dealt with, treatment began with a demonstratjon of simple relaxation exercises for daily practice at home. At this point patients were atso instructed in the use of a diary record of anxious mood and thought frequency, described below. Relaxation training continued in the second and third sessions. following the usual progression employed prior to systematic desensitisation. After this, patients were randomly allocated to thought-stopping first or ‘desensitisation’ first, two weeks being allowed for each. In thought-stopping, patients were instructed to relax for five minutes, and then * This research was supported by a grant from the Medicai Research Council, U.K. 503
504
CASE
HISTORIES
AND
SHORTER
COMMUNICATIONS
to begin concentrating on a designated anxiety thought which was to be signalled as soon as it was clear. At this point the therapist shouted ‘stop’ and instructed the patient to substitute a pre-arranged alternative thought. After this the procedure followed the usual sequence of increasing patient responsibility for terminating the thought without intervention by the therapist, until the induction and termination of thoughts could be performed by the patient alone. Emphasis was placed on daily home practice between sessions, and patients were encouraged to experiment with variations (such as snapping a rubber band round the wrist) to find the most effective way of stopping the designated thought. As well as daily practice sessions, they were also asked to apply the method as appropriate to any spontaneously arising thoughts throughout the day. In ‘cognitive desensitisation’ the procedure applied was identical until the point at which the patient signalled that a thought was clear, at which time they were not instructed to stop it, but instead to tolerate it, and allow it to remain for as long as it seemed clear. When patients became anxious they were encouraged to wait until the anxiety subsided, but if the reaction was excessive, or the patient refused to continue, a less intense form of the anxiety thought was found; that is, a simple hierarchy was constructed. As a rule any anxiety rapidly dissipated and after one to two minutes the patient signalled that the thought had faded. After a brief pause for relaxation, the sequence was then repeated. Equivalent instructions were given for dealing with anxiety thoughts arising between sessions. When crossing over from one treatment to the other, that is on the sixth treatment session, a rationale was given for the change. This took the form of an explanation that the inethod used to date, whether thou~t-stopping or d~sit~ation, would probably prove best in some circumstances, but not ah. For this reason, training would be given in an alternative procedure, and for these next two weeks the patient should concentrate completely on this new method. At the end of the cross-over sequence patients would thus be in a position to choose when to apply each method as appropriate. The final (eighth) session was used to gather reports on the previous weeks progress, and to discuss future self-help practice. Assessmerzt At the screening interview, and at the follow-up interviews, patients were questioned by the independent assessor as to the intensity and frequency of anxiety. Clinical ratings of severity were made in order to assess overali change in clinical anxiety, although this was not ‘blind’ since the assessor knew that patients would have received both treatments, remaining in ignorance only of the order in which they were given. Measures discriminating between the two procedures given in balanced order, thought-stopping and desensitisation, were thus confined to patients self-report. This was available from two sources, a weekly mood male (McNair and Lorr, 1964). and the detailed diary records made by patients every three hours through the day. At 9.OOan-1,12.OOam, 3.oOpm, 6.OOpm and 9.oOpm, they recorded anxious mood on a O-10 scale, estimated time in minutes spent thinking the specified target thoughts in the preceding three hours, and ratings of the effect (if any) which those thoughts had on their mood. RESULTS
All patients entering the study were able to specify some thought content which they associated with anxiety. although some found this much less easy to verbalise than others. In two cases the thoughts were cued by real or anticipated noises (e.g. ‘they are doing it to annoy me’), somatic cues interpreted as indications of possible illness or death figured prominently in five cases, in two cases worries also inciuded pessimistic thoughts about the future in general, and one patient (the least responsive) was preoccupied with the thought that buildings might collapse. In terms of changes in clinically rated anxiety, all patients except this one were rated to have improved in varying degrees, although only two could be judged virtually symptom free on follow-up, and the average rated change was small (0.8 points on the assessors five point anxiety scale, and patients average self-rating of improvement was just above ‘slightly better’). The main analysis of self-report scores during and following each of the two treatment periods intended to modify anxiety-related thoughts, was carried out using analysis of variance on mean scores during the two weeks following intr~uction of each procedure. Analysis of anxiety ratings and effect of thoughts on mood were based on average scores over each two week treatment period, but due to a markedly skewed distribution of estimated time spent engaged in anxiety-associated thoughts, this latter score was re-analysed after conversion to a ratio score by dividing by levels recorded in the first base-line week. In each analysis, however, no significant differences were found. and mean scores were very similar (see Table 1). Analysis of weekly mood estimates from the adjective mood scale was confined to anxiety/tension and depression scores: again no differences were found. A finai series of analyses concerned the comparison of scores during each two week block of cognitive treatment with the equivalent scores averaged over the second and third weeks of treatment, that is, during the latter part of relaxation training. Significant reductions over time were found for all measures except the mean ratings of anxiety derived from the diary ratings made every three hours. Clearly, however, this comparison confounds type of treatment with other changes over time, and only serves to show that the observed changes cannot be attributed to random error of measurement.
Thought duration mm/3 hr ratw to base-bne Thought impact (O-IO) Mood scale ratings anxiety/tension (C-24) depression (%36)
26 0.89 2.0 128 10.6
18.4 0.6 1.7 9.7 6.7
I
17.5 0.62 1.7 9.9 7.9
CASE HISTORIESAND SHORTER COMMUNICATIONS
505
DISCUSSION
The apparently positive aspects of these results; that anxious patients can report repetitive anxiety-associated cognitions (usually concerning possible catastrophic or personally threatening events) and that a self-reported reduction in such cognitions is accompanied by improvement on the mood scale, does not in any way provide evidence of a causal relationship between these thoughts and the complaint of excessive anxiety. Both this, and the tendency for most patients to be rated as clinically improved, can be attributed to non-specific variables such as the expectation of therapeutic change. To provide clearer evidence it would have been necessary to demonstrate that one of the equally plausible procedures given in balanced order had a significantly greater effect in reducing the frequency (or impact) of anxiety-associated cognitions than did the other, and additionally that the more effective procedure also produced correspondingly greater improvements in mood. It was obviously anticipated that thought-stopping should have reduced the time spent engaging in anxious thoughts more than did desensitisation, and the failure to show even this casts considerable doubt on the supposed mechanism of the procedure. In this respect the present negative results are consistent with an earlier failure to show that stopping obsessive thoughts had a better result than stopping neutral thoughts (Stern, Lipsedge and Marks, 1973). As a result of this failure of thought-stopping to have any specific effects, the initial hypothesis of the present study could not be properly tested. In addition to calling into question the basis of thought-stopping as a technique, the study suggests further questions for investigation. Although expectation for change may well be sufficient explanation of the modest clinical improvements seen, this explanation seems less likely in view of the patients responses on a pre-treatment questionnaire asking about likely benefit from four of the treatment components used. On a O-4 scale, mean rating of thought-stopping was highest at 3.7 (between ‘very’ and ‘extremely’ helpful), using a diary was lowest at 1.6 (between ‘slightly’ and ‘moderately’ helpful), with relaxation and desensitisation in between with a mean rating of about three. After treatment, the perceived benefit from all components was approximately equal with a mean rating of two (‘moderately’ helpful), so that all were reduced in perceived helpfulness except for the use of the diary, which showed a slight gain. As described by some of the more articulate and responsive patients, it was as if the upsetting thoughts which had previously been a cue for perseverative alarm or ineffectual efforts to obtain relief, now served as a cue to do something different, although the exact nature of the alternative response was unimportant. The self-monitoring involved in keeping a diary of anxiety-associated thoughts, which at first seemed irksome and unnecessary, was later judged helpful by some patients in reinterpreting the thoughts as behaviour which could be changed, and as a prompt to implement the appropriate technique. It is tempting to speculate that in those cases where the treatment package as a whole was successful, its effectiveness was attributable to a process common to both techniques; for example a sequence in which self-monitoring prompts some alternative activity that distracts attention from the anxiety-evoking content of thoughts, and encourages the idea that they can be changed. To determine if treatments containing such common elements are more effective than those without them must obviously await further research. University Department 0s Psychiafry,
ANDREW MATHEWS* PHYLLIS SHAW
The Wameford Hospital, Oxford, England
* Requests for reprints should be sent to: Professor A. Mathews, Department Hospital Medical School, Cranmer Terrace, Tooting, London SW17, England.
of Psychology, St. Georges
REFERENCES BECK A. T.,LAUDE R. and BOHNERT M. (1974) Ideational components
of anxiety neurosis. Arch. gen. Psychiat.
31, 319-325. MCNAIR D. M. and LORR M. (1964) An analysis of mood in neurotics. J. Abnorm. sot. Psychol. 69, 620-627. STERN R. S., LIPSEDGE M. S. and MARKS I.M. (1973)Obsessive ruminations: a controlled trial of thoughtstopping technique. Behau. Res. and Therapy 11, 659662. WOLPE J. (1973) The Practice of BehoviourTherapy. Pergamon Press, New York.