Verbal control of delusions

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  • BEHAVIOR THERAPy 21, 461-479, 1990

    Verbal Control of Delusions

    C. F. LOWE

    P. D. J. CHADWICK

    Department of Psychology University College of North Wales

    Bangor, UK

    The verbal descriptions or rules people formulate to describe both themselves and their interactions with others can profoundly influence their subsequent behavior and rule formation. Delusions may be thought of as being one class of rules. Two single- case experiments, each comprising a multiple-baseline design across three behaviors (delusions), are reported. Each experiment incorporated a number of measures of delu- sional thinking and an intervention designed to challenge these delusions and to pro- vide the clients concerned with alternative rules with which to organize their behavior. In both experiments the intervention proved highly effective in reducing the degree of conviction in the delusional beliefs, and there was some generalization of the effects across beliefs. A number of secondary measures helped to identify associated clinical benefits, and there was evidence that both clients used the alternative rules to regulate their behavior during a 6-month follow-up phase.

    Recent years have seen a growing awareness within behavior analysis and other areas of psychology of the importance of language or rules in the regu- lation of behavior. The process of learning to describe our environment alters our relation to it, because in so doing we organize and structure our subse- quent interactions (Lowe, 1979; 1983; Lowe, Horne, & Higson, 1987; Skinner, 1969; Vygotsky, 1962; 1978; Zettle & Hayes, 1982). In recognition of the potency of the regulatory function of language, a number of researchers have come to understand many clinical disorders as being maintained, at least in part, by the ways in which clients describe both themselves and their interactions with others (e.g., Abramson, Seligman, & Teasdale, 1978; Beck, 1967; Hayes, 1987; Kelly, 1955). It seems plausible that delusional beliefs may also be main- tained, to some extent, in this way. Strauss (1969) has argued that delusional behavior is on a continuum function with normal behavior, the difference be- tween them being quantitative rather than qualitative. Delusions, like other strongly held beliefs, influence the way events are interpreted, and are simi- larly resistant to change (e.g., Maher, 1988). Indeed, because of this apparent continuity with other beliefs, the definition of what actually constitutes a de- lusion is somewhat problematic (see Garety, 1985).

    461 0005-7894/90/0461-047951.00/0 Copyright 1990 by Association for Advancement of Behavior Therapy

    All rights of reproduction in any form reserved.

  • 462 LOWE AND CHADWICK

    This study was conducted in 1988 while P.D.J. Chadwick was in receipt of a studentship funded by Clwyd Health Authority. Thanks are due to Mabel Tannahill for her help in setting up the research programme, to Peter Higson for help and guidance throughout and to many other staff of Clwyd Health Authority, all of whom contributed to the success of this project. Finally we should like to express our gratitude to the two individuals who participated as the main subjects of this study. Correspondence concerning this article should be addressed to C. F. Lowe, Depart- ment of Psychology, University College of North Wales, Bangor, Gwynedd LL57 2DG, United Kingdom.

    Attempts at modifying delusions in people diagnosed as schizophrenic have been scarce, and methodological limitations abound. Basic requirements have frequently been overlooked, such as baseline data to describe any ongoing variability, and long-term follow-up data to determine the permanence of any change; a study by Alford (1986) remains one of the few to have met both criteria. Also, treatments have often combined a number of different inter- ventions with little or no attempt at component analysis. Chadwick and Lowe (1990) used a multiple-baseline design across 6 people diagnosed as schizo- phrenic according to the criteria given in the Diagnostic and Statistical Manual of Mental Disorders III (American Psychiatric Association, 1980), in order to evaluate the impact of two interventions on a number of dimensions of delusional behavior. The interventions were: first, a structured verbal chal- lenge, and second, a reality-testing intervention during which the client and researcher collaborated to devise a simple test of the rules (see Beck, 1967). The theoretical rationale for the verbal challenge came from the literature on verbal self-regulation within normal and clinical populations (Lowe, Horne, & Higson, 1987). In accordance with numerous clinical approaches to changing covert and overt verbal behavior, the interventions were designed: (1) to give the client information about the ways in which rules or beliefs can govern behavior, (2) to generate alternatives to the maladaptive rules, and (3) to assist the client to monitor and evaluate these alternative rules. Of the 6 clients, 2 rejected their beliefs completely and 3 others reported significant reductions in the degree of belief conviction. These effects were maintained over a 6-month follow-up period, and there was evidence to suggest that the intervention had enabled 5 of the clients to effectively regulate their delusional thinking.

    A multiple-baseline design can also be conducted across behaviors (Kazdin, 1982), and is appropriate in the cases of clients who hold more than one delu- sional belief. Our present study comprises two single-case experiments, each employing a multiple-baseline design across 3 beliefs. In both experiments, after a minimum of 5 weeks at baseline, a verbal challenge intervention was separately directed at each delusional belief in turn, with an intervention of at least four weeks between each intervention. A number of dimensions of delusional experience were measured throughout, and long-term follow-up data were collected. Because the verbal challenge intervention was applied to each belief separately, the study offered a unique opportunity to observe the rela- tionships between each client's three delusions and, in particular, how reduc- tion of conviction in one affected the other two beliefs.

  • VERBAL CONTROL OF DELUSIONS 463

    GENERAL METHOD Subject Selection

    As in our earlier study (Chadwick & Lowe, 1990) participation was on a voluntary basis; clients who had held a delusional belief for the previous 2 or more years were asked whether they were willing to meet with a researcher who wished to discuss their beliefs. Two clients took part, both of whom were outpatients on a stable drug regime. Medication was held constant during the study. Both clients were diagnosed as schizophrenic according to the Diag- nostic and Statistical Manual of Mental Disorders (DSM-III) criteria (Amer- ican Psychiatric Association, 1980); these diagnoses were made independently by P.D.J. Chadwick and a clinical psychologist. Each subject presented with 3 delusional beliefs; there was no other delusional thinking.

    Measures Following Brett4ones, Garety and Hemsley (1987) we measured both de-

    gree of belief conviction, and preoccupation, using a modified form of Shapiro's (1961) Personal Questionnaire (Phillips, 1977). A Personal Questionnaire (PQ) was also used to measure the degree of anxiety experienced by the client while thinking about his or her beliefs. We offered each client five statements of in- tensity of belief conviction, preoccupation, and anxiety, respectively, and both accepted these statements as valid descriptions. Table 1 details the specific wording used for each client and shows that, while the conviction measure was concerned with how certain the client was feeling at that particular point in time, the preoccupation and the anxiety statements referred to the level of

    TABLE 1

    THE WORDING USED FOR THE PERSONAL QUESTIONNAIRE MEASURES OF CONVICTION,

    PREOCCUPATION, AND ANXIETY

    Score Conv ic t ion P reoccupat ion Anx ie ty

    0

    My be l ie f is a lmost Over the last week I Th ink ing about my be l ie f

    def in i te ly fa lse thought about my I get very s l ight ly

    bel ie f once anx ious

    1 . . p robab ly fa lse . . . 3 t imes . . . s l ight ly anx ious

    2

    . . may or may not be t rue . . .onceaday . . . fa i r ly anx ious

    3

    . . p robab ly t rue . . . 4 t imes a day . . . very anx ious

    4

    . . a lmost def in i te ly t rue . . . once an hour . . . ex t remely anx ious

    5

    N .B . Persona l Quest ionna i re scores fal l between two verba l descr ip t ions ; one might respond

    more to p robab ly t rue but less to a lmost def in i te ly t rue.

  • 464 LOWE AND CHADWICK

    symptom intensity experienced over the preceding week. The five statements for each measure were written on separate cards and ranked by the client. At the administration stage each card was presented randomly, and the client was required to say whether the intensity was more or less than that stated on the card. The score on each occasion was provided by the number of cards to which the client replied that the symptom intensity was greater than that stated on the card. The scale allowed for comparisons to be made for each subject across time. Following Hole, Rush, and Beck (1979), we measured degree of belief conviction by asking the client for a percentage rating of conviction, and this was taken after the PQ conviction score These four measures were administered at the close of every session throughout the entire study.

    Again, in keeping with Brett-Jones et al. (1987), accommodation and reac- tion to hypothetical contradiction (RTHC) were assessed. The accommoda- tion measure was concerned with the aw