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Experimental manipulation of intolerance of
uncertainty: A study of a theoretical model of
Article in Behaviour Research and Therapy · October 2000
DOI: 10.1016/S0005-7967(99)00133-3 · Source: PubMed
3 authors, including:
Patrick Gosselin Université de Sherbrooke 50 PUBLICATIONS 873 CITATIONS SEE PROFILE All in-text references underlined in blue are linked to publications on ResearchGate, Available from: Patrick Gosselin letting you access and read them immediately. Retrieved on: 16 October 2016 Behaviour Research and Therapy 38 (2000) 933±941 www.elsevier.com/locate/brat Shorter communication Experimental manipulation of intolerance of uncertainty: a study of a theoretical model of worry Robert Ladouceur a,*, Patrick Gosselin a, Michel J. Dugas b a Ecole de Psychologie, UniversiteÂ Laval, Ste-Foy, Que., Canada G1K 7P4 b Department of Psychology, Concordia University, 1455 de Maisonneuve West, Montreal, Que., Canada H3G 1M8 Received 28 June 1999; received in revised form 28 June 1999 Abstract Intolerance of uncertainty has been identi®ed as an important variable related to worry and Generalized Anxiety Disorder (GAD) [Dugas, M. J., Gagnon, F., Ladouceur, R., & Freeston, M. H.
(1998). Generalized anxiety disorder: a preliminary test of a conceptual model. Behaviour Research and Â Therapy, 36, 215±226; Ladouceur, R., Dugas, M. J., Freeston, M. H., Rheaume, J., Blais, F., Boisvert, J.-M., Gagnon, F., & Thibodeau, N. (1999). Speci®city of Generalized Anxiety Disorder symptoms and processes. Behavior Therapy, 30, 197±207 ]. The goal of the present study was to clarify the relationship between this cognitive process and worry by experimentally manipulating intolerance of uncertainty. A gambling procedure was used to increase intolerance of uncertainty in one group (N = 21) and to decrease intolerance of uncertainty in another group (N = 21). The results indicate that participants whose level of intolerance of uncertainty was increased showed a higher level of worry, compared to participants whose level of intolerance of uncertainty was decreased. These results provide some initial clari®cations as to the causal nature of the link between intolerance ofuncertainty and worry. These results are coherent with our theoretical model of worry and GAD (Dugas et al., 1998), which stipulates that intolerance of uncertainty plays a key role in the acquisition and maintenance of excessive worry. 7 2000 Elsevier Science Ltd. All rights reserved.
1. Introduction Since the publication of the Diagnostic and Statistical Manual of Mental Disorders, fourth * Corresponding author. Tel.: +1-418-656-3996; fax: +1-418-656-3646.
E-mail address: email@example.com (R. Ladouceur).
0005-7967/00/$ - see front matter 7 2000 Elsevier Science Ltd. All rights reserved.
PII: S 0 0 0 5 - 7 9 6 7 ( 9 9 ) 0 0 1 3 3 - 3 934 R. Ladouceur et al. / Behaviour Research and Therapy 38 (2000) 933±941 edition, (DSM-IV) (APA, 1994), excessive and uncontrollable worry is considered as the core feature of Generalized Anxiety Disorder (GAD). As mentioned by Brown, O'Leary and Barlow (1993), changes in the conceptualization of GAD over the last few years have provided new directions in research on worry (see Barlow, 1988; Borkovec, Metzger & Pruzinsky, 1986;
Dugas, Gagnon, Ladouceur & Freeston, 1998; Macleod, Williams & Bekerian, 1991).
Our research team has recently proposed a theoretical model of GAD and excessive worry that includes four cognitive variables: intolerance of uncertainty, poor problem orientation, cognitive avoidance and erroneous beliefs about the usefulness of worry (Dugas et al., 1998).
Among these four cognitive variables, intolerance of uncertainty is viewed as the most important and is believed to play a key role in the acquisition and maintenance of excessive worries. The preliminary results of a cognitive-behavioral treatment based on this model demonstrate good treatment ecacy (Dugas & Ladouceur, in press).
Although many authors have included the notion of uncertainty in their model of GAD (Andrews & Borkovec, 1988) and anxiety (Garber, Miller & Abramson, 1980), Krohne (1989,
1993) was the ®rst author to include the construct of intolerance of uncertainty in his general model of anxiety. According to this model, intolerance of uncertainty and intolerance of emotional arousal are the main variables underlying anxiety disorders. He suggested that an elevated level of intolerance of uncertainty provokes reactions of hypervigilance when individuals are faced with uncertain or ambiguous problems, while an elevated level of intolerance to emotional arousal stimulates cognitive avoidance reactions. Excessive anxiety would then result from the constant shifting from a hypervigilant state (linked to the uncertainty of the situation) to a state of avoidance (linked to the anxious reactions felt by the individual). Even though the components included in Krohne's model (1993) open interesting avenues for research, they need to be more precisely de®ned.
Our previous work in the ®eld of anxiety lead us to de®ne intolerance of uncertainty as a predisposition to react negatively to an uncertain event or situation, independent of its probability of occurrence and of its associated consequences. In other words, for the same uncertain situation, two individuals with identical perceptions of both its probability of occurrence and consequences may dier in their threshold of tolerance towards the situation.
An individual who is intolerant of uncertainty would evaluate the situation as being disturbing, even unacceptable, whereas another individual who is tolerant of uncertainty would assess the situation as being less disturbing. Thus, the ®rst person's threshold of tolerance is lower than that of the second individual. This de®nition emphasizes the subjective appraisal of uncertainty by the individual and represents the reality expressed by individuals during therapy.
Considering that everyday life necessarily involves uncertain and/or ambiguous situations, individuals who are intolerant of uncertainty will perceive many sources of danger in their daily life. Numerous worries will thus follow, as well as negative emotions, such as anxiety and depression (Dugas, Freeston, Blais & Ladouceur, 1994; Macleod & Mathews, 1988). This con®rms the results of previous studies indicating that worry is characterized by (1) a tendency to de®ne ambiguous situations as threatening (Butler & Mathews, 1983, 1987; Russel & Davey, 1993), (2) an elevated estimation of risk (Butler & Mathews, 1983, 1987; Vasey & Borkovec,
1992) and (3) a tendency to generate negative scenarios in uncertain situations (Macleod et al., 1991; Tallis, Eysenck & Mathews, 1991a; Vasey & Borkovec, 1992). This could also explain why high worriers are slower to make a decision when confronted with ambiguous stimuli R. Ladouceur et al. / Behaviour Research and Therapy 38 (2000) 933±941 935 (Ladouceur, Talbot & Dugas, 1997; Metzger, Miller, Cohen, Softka & Borkovec, 1990; Tallis, 1989; Tallis, Eysenck & Mathews, 1991b).
Certain studies have recently demonstrated the sensitivity and the speci®city of the relationship between intolerance of uncertainty and worry (e.g. Dugas, Freeston & Ladouceur, Â 1997; Freeston, Rheaume, Letarte, Dugas & Ladouceur, 1994; Gosselin, Dugas & Ladouceur, 1998). However, no study has yet manipulated level of intolerance in order to determine its impact on worry. As mentioned by Garber and Hollon (1991), experimental manipulation may demonstrate causality and thus may lead to a better understanding of the role of numerous processes in the acquisition and maintenance of diverse problems such as Bulimia (Cooper, Â Clark & Fairburn, 1993), Obsessive±Compulsive Disorder (Ladouceur, Rheaume & Aublet, 1997; Ladouceur et al., 1995; ) and Panic Disorder (Clark et al., 1988).
In this study, a computerized roulette game was developed in order to increase and decreased intolerance of uncertainty. While taking into consideration the current de®nition of intolerance of uncertainty, we developed a task whereby the uncertainty of the situation was acceptable for one group, and unacceptable for a second group, without changing either the objective probability of winning (probability of occurrence) or the consequences associated with the situation. The main hypothesis of this study was that, following manipulation of intolerance of uncertainty, participants in the increased intolerance group would report a higher level of worry compared to participants in the decreased intolerance group.
2.1. Participants Forty-two (42) students participated in this study. The sample included 30 women with a mean age of 23.8 years (S.D.=7.07) and twelve men with a mean age of 21.7 years (S.D.=1.92). The participants were randomly assigned to one of the two experimental conditions (increased or decreased intolerance of uncertainty). However, since a gender dierence is often observed in the tendency to worry, an equivalent number of women and men were assigned to each condition. Both experimental conditions consisted of 21 participants.
2.2. Material and procedure
A multimedia IBM computer with a color screen was used in this study. The computer was equipped with a computerized roulette game that simulates those found in casinos. Student were invited to an individual meeting lasting approximately 1 hour with the aim of studying people's thoughts about gambling. None of the participants were informed beforehand as to the real goal of the study, which consisted of the manipulation of intolerance of uncertainty.
The experimenter presented himself as part of a research team studying beliefs associated with gambling. After brie¯y explaining the experimental task (roulette game), the experimenter asked the participants to sign a consent form. Once the task was completed, the participants ®lled out two questionnaires; a manipulation check measure, and a measure of worry.
936 R. Ladouceur et al. / Behaviour Research and Therapy 38 (2000) 933±941
2.3. Experimental task
The task consisted of a computerized roulette game in which the player must bet on 15 consecutive trials. Each participant was allowed to bet on one of three columns of 12 numbers.
For each trial, a betting amount of $2 was set. Each participant began the task with a $20 bankroll. The roulette game was programmed so that the ®nal amount for each participant, after all betting was ®nished, was $14.
The experimenter ®rst explained the rules of the roulette game. Emphasis was placed on the probability associated with the three dierent types of bets; (i.e. one chance in two if the bet was on colors, one chance in 36 if the bet was on a single number, one chance in three if the bet was placed on one column). After having veri®ed that the participant understood the various probabilities associated with the game, the experimenter indicated that for this study s/he must bet on columns, thereby setting a one in three chance of winning on each trial. The experimenter then explained that to create a situation that most resembles a real game with stakes, an amount of $100 would be donated to a Foundation (®ctitious). However, the experimenter stipulated that the money would be donated to the Foundation only if the ®nal amount for each participant, after 15 trials, was equal or superior to $20 (equal or superior to the initial amount). If the ®nal amount was inferior to $20, nothing would be donated to the Foundation.
2.4. Increase in level of intolerance
The participants in this group received, several times throughout the experiment, information which led subjects to evaluate their chances of winning (probability) as being unacceptable (e.g.
``We already did a study of this type last year, and it's a shame, people had better chances of winning then. People bet on colors, and therefore had one in two chances of winning. Too bad we brought this back to a one in three chance. In fact, I am beginning to notice, by watching people play, that there is a large dierence between one chance in three and one chance in two, that is 33 versus 50%. The chances of winning are much worse!'').
2.5. Decrease in level of intolerance
The participants in this group received instructions to the eect that the probability of winning, given one chance in three, is high (e.g. ``We have already done this with one chance in 36, and people never won, now there is no problem with that, since we have one chance in three to win''). The experimenter also told the participants that it was only a game; if they didn't win, someone else would end up winning so that the Foundation would eventually gets its money.
2.6. Instruments 2.6.1. Manipulation check measure Six questions evaluated the level of intolerance of uncertainty of the participants during the R. Ladouceur et al. / Behaviour Research and Therapy 38 (2000) 933±941 937 Table 1 Questions assessing intolerance of uncertainty during the experimental task No. Questions (1) Not being sure of winning money concerned me (2) If I had been sure of winning money, I would have been less bothered by the task (3) I found it was a shame that there were no guarantees that money would be won for the Foundation (4) If I had been sure of winning money regardless of my bet (column), I would have been less preoccupied by the task (5) Not being sure of winning money for the Foundation bothered me (6) The uncertainty of winning money caused me stress game situation (see Table 1). These questions were developed based on items from the Intolerance of Uncertainty Scale (IUS; Freeston et al., 1994).
2.6.2. Dependent variable measure Three questions were developed in order to measure the participants' worry regarding the Foundation. These questions were based on items from the Penn State Worry Questionnaire (PSWQ; Meyer, Miller, Metzger & Borkovec, 1990; Ladouceur et al., 1992). Table 2 presents the three items designed to measure the participants' level of worry about the Foundation.