اثر انحراف فکر و سبک مقابله بر روی مواجهه در شرایط زنده برای هراس خاص عنکبوتی

Recent studies have generated mixed findings regarding the effects of distraction on exposure-based treatments. Results have also been inconsistent regarding the effects of monitoring and blunting coping styles on outcome. The present study attempted to integrate these two areas of research. We hypothesized that the effect of distraction on treatment outcome might depend on coping style. Specifically, we predicted that for blunters (i.e., individuals who tend to avoid threat-related information), distraction would interfere with the effects of exposure. However, we predicted that distraction might benefit monitors (i.e., individuals who tend to seek out threat-related information). Sixty individuals with a specific phobia of spiders underwent a single, two-hour session of exposure treatment. During the first hour, half of the participants were distracted by listening to an audiotape and the other half underwent exposure without distraction. In the second hour, all participants underwent focused exposure. Based on measures of heart rate, subjective fear, and behavioral testing, participants improved after one hour of treatment, and improved further during the second hour. However, neither distraction, coping style, nor their interaction had a significant effect on outcome. The present study provides support for the benefits of behavioral treatment for specific phobias. However, our hypotheses regarding distraction and coping style were not confirmed.

In the DSM-IV (American Psychiatric Association, 1994), the essential feature of specific phobia is a marked and persistent fear of a circumscribed object or situation (e.g., heights, animals, etc.) that causes significant distress or impairment in a person's social or occupational functioning. Several epidemiological studies (e.g., Eaton, Dryman & Weissman, 1991 and Kessler et al., 1994) have found the lifetime prevalence of specific phobias in the general population to be close to 11%. Furthermore, animal phobias are among the most prevalent of specific phobias (Bourdon et al., 1988 and Curtis, Magee, Eaton, Wittchen & Kessler, 1998). For specific phobias, in vivo exposure (i.e., exposure conducted “in person”) to the feared object or situation appears to be the treatment of choice, with improvement rates of 90% or more for some phobia types (for a review, see Antony & Barlow, 1998 and Antony & Swinson, 2000). Despite the well established efficacy of exposure-based treatments, it is far from clear why exposure helps to reduce fear and what mechanisms induce the emotional change (Muris, de Jong, Merckelbach, & van Zuuren, 1993a). According to Lang's (1977) bioinformational model of fear and fear reduction (see Foa & Kozak, 1986), the mechanism by which focused exposure leads to fear reduction involves changes to the “meaning proposition” of the fear structure. Following exposure, feared events become perceived as less probable and less threatening as a result of short- and long-term habituation. In other words, Foa and Kozak (1986) propose that fear reduction depends primarily on the processing of corrective information during exposure therapy. Cognitive avoidance strategies, such as distraction (e.g., imagining to be somewhere else, concentrating on non-feared elements of the situation, etc.), diminish the encoding of fear-relevant information and impede activation of fear. Distraction is hypothesized to prevent emotional processing, and thereby prevent habituation and fear reduction (Foa & Kozak, 1986). The notion that distraction prevents long-term fear reduction during exposure therapy is consistent with other cognitive and behavioral theories as well (e.g., Barlow, 1988 and Rachman & Bichard, 1988). 1.1. Research on distraction and exposure As reviewed by Rodriguez and Craske (1993), all theories of exposure therapy suggest that distraction during exposure should have a negative impact on outcome. Distraction is hypothesized to impede long-term fear reduction, although it may aid in short-term fear reduction by temporarily limiting the salience of the feared cue. However, despite the predicted effects of distraction on exposure outcome, empirical findings have been mixed. For example, Grayson, Foa, and Steketee (1982) employed a cross-over design in which 16 patients with obsessive–compulsive disorder (OCD) underwent two 90-minute sessions of intense exposure on two separate days. During each session, participants held their most feared “contaminated” stimulus throughout the entire 90 minutes. One of the sessions (a focused attention condition) consisted of conversation between the participant and the therapist regarding aspects of the stimulus and of the participant's discomfort. The other session (a distraction condition) consisted of the therapist and the participant playing video games during the exposure. A linear reduction of subjective fear and of heart rate (habituation within sessions) was found during the exposure sessions regardless of whether attention was focused on, or distracted from, feared stimuli. However, increased attention to the feared stimuli appeared to facilitate between-session habituation. A second study by the same group (Grayson, Foa, & Steketee, 1986) extended the initial investigation by using the same procedures for focused and distracted exposures in a between-groups design. Participants were 17 individuals with OCD. Heart rate decreased during exposure when attention was focused continually on the feared stimulus and the feelings generated during the session. In contrast, when attention was distracted from the stimulus, heart rate remained elevated throughout the 90-minute exposure (Grayson et al., 1982). However, self-rated fear showed a greater reduction in the distraction condition than in the focused attention condition, especially during the first exposure session. These results appear to be at odds with their earlier findings in which self-rated fear was equivalent for both conditions in the first session. Although heart rate decreases during exposure were greatest when attention was focused on the feared stimulus, changes in subjective fear were greater when attention was distracted. Craske, Street, and Barlow (1989) examined the effects of distraction during exposure in 30 patients with panic disorder and agoraphobia who underwent 11 group sessions of cognitive restructuring and in vivo exposure (with exposure sessions lasting up to 60 minutes). Participants in the focused exposure condition were trained to monitor bodily sensations during in vivo exposure to feared situations and to use thought-stopping and self-focusing statements to interrupt distraction from their sensations. In contrast, participants in the distraction condition were trained to engage in cognitive distraction tasks (e.g., spelling, word rhyming, etc.) during exposure and to use thought-stopping and task-oriented self-statements to interrupt internal focusing of attention. The authors reported a tendency for improvement in both conditions, with the distraction group showing greater improvement at post-assessment. However, at 6-month follow-up, the pattern reversed, with the focused group evidencing greater improvement. Craske, Street, Jayaraman, and Barlow (1991) examined the immediate effects of distraction on the level of fear experienced by 19 students with snake and spider phobias who underwent three exposure conditions and a baseline period, each lasting 6 minutes. In the distracted condition, participants listened for specific target words during audiotaped passages while continuing to observe the phobic stimulus. In the focused condition, participants were prompted to focus on features of the phobic stimulus and their own emotional responses. Subjective fear ratings increased during the focused exposure phase, whereas they did not change during the distraction and natural exposure phases. Heart rate did not differ between conditions. In another study, Rodriguez and Craske (1995) examined the short- and long-term effects of distraction on fear reduction during exposure in a group of 60 psychology students with animal phobias. Participants were exposed to their feared animal in a container that was situated at eye level, at the end of a 20-foot long corridor. Half of the participants underwent low intensity exposure and were instructed to approach the animal until their fear had decreased to a moderate level (40–50 on a 100-point fear scale). The remaining participants underwent high intensity exposure and were instructed to approach the feared stimulus until they experienced strong fear (70–80 on a 100-point fear scale). During the exposure, participants also viewed slides that varied in content. Level of distraction (high vs low) was manipulated by presenting only neutral slides in the low distraction condition, and positive or negative slides in the high distraction condition. Slide images were projected immediately behind the animal. Under conditions of high intensity fear (but not low-intensity fear), distraction impeded the effects of exposure, as measured by self-reported fear reduction as well as a behavioral approach test (BAT). These results support conceptualizations of distraction as an inhibitor of exposure effects. However, counter to the authors' prediction, the effect was evident only under conditions of high intensity exposure. The authors argued that distraction is not effective unless a certain threshold of fear intensity is reached (Rodriguez & Craske, 1993). The lack of consistency across studies is difficult to interpret due to the differences in methods used to define distraction (e.g., visual attention, cognitive attention, tactile attention) as well as differences in diagnostic group (e.g., OCD, panic disorder with agoraphobia, specific phobia). Thus, it is difficult to draw conclusions from the literature. To summarize, some research indicates that distraction does not have a negative impact on exposure therapy for immediate outcome (e.g., Craske, Street, Jayaraman & Barlow, 1991 and Grayson, Foa & Steketee, 1982), and may even have a facilitating effect (Craske et al., 1989). However, evidence does suggest that distraction may impede long-term outcome (Craske, Street & Barlow, 1989, Grayson, Foa & Steketee, 1982 and Haw & Dickerson, 1998). Other research indicates that the effects of distraction on the effectiveness of exposure therapy depend on the outcome measure utilized. There is some evidence that distraction may have a facilitating effect on outcome based on self-rated fear reduction (Craske, Street, Jayaraman & Barlow, 1991, Grayson, Foa & Steketee, 1986 and Penfold & Page, 1999) but a negative impact on outcome based on heart rate reduction (Grayson et al.). Only one study has provided partial support for the prediction that distraction should impede fear reduction (Rodriguez & Craske, 1995).