Measuring the role of psychological inflexibility in Trichotillomania

Highlights

• A new Trichotillomania-specific version of the AAQ-II is evaluated.

• The AAQ-TTM demonstrates two factors and satisfactory psychometric properties.

• Psychological Inflexibility mediates the affect and hair pulling relationship.

• Psychological Inflexibility might be a core feature of Trichotillomania.

Abstract

Psychological Inflexibility (PI) is a construct that has gained recent attention as a critical theoretical component of Acceptance and Commitment Therapy (ACT). PI is typically measured by the Acceptance and Action Questionnaire-II (AAQ-II). However, the AAQ-II has shown questionable reliability in clinical populations with specific diagnoses, leading to the creation of content-specific versions of the AAQ-II that show stronger psychometric properties in their target populations. A growing body of the literature suggests that PI processes may contribute to hair pulling, and the current study sought to examine the psychometric properties and utility of a Trichotillomania-specific version of the AAQ-II, the AAQ-TTM. A referred sample of 90 individuals completed a battery of assessments as part of a randomized clinical trial of Acceptance-Enhanced Behavior Therapy for Trichotillomania. Results showed that the AAQ-TTM has two intercorrelated factors, adequate reliability, concurrent validity, and incremental validity over the AAQ-II. Furthermore, mediational analysis between emotional variables and hair pulling outcomes provides support for using the AAQ-TTM to measure the therapeutic process. Implications for the use of this measure will be discussed, including the need to further investigate the role of PI processes in Trichotillomania.

Introduction

Trichotillomania (TTM), or hair pulling disorder, is an obsessive-compulsive spectrum disorder characterized by the repeated pulling of one׳s own hair, resulting in significant hair loss (American Psychiatric Association [APA], 2013). Research has revealed two styles of pulling: “automatic” and “focused” (Christenson et al., 1991). “Automatic” pulling is performed with little control or awareness, whereas “focused” pulling appears to be a more purposeful process. Some have suggested that “focused” pulling may function to regulate affect and/or aversive cognitions (Begotka et al., 2004, Woods et al., 2006). Supporting this idea, Diefenbach et al. (2002) found that people with TTM report reductions in anxiety, tension, and boredom following pulling episodes.

The most empirically supported behavioral intervention for TTM is Habit Reversal Training (HRT; Azrin et al., 1980, Rosenbaum and Ayllon, 1981, Tarnowski et al., 1987, Mouton and Stanley, 1996, Stoylen, 1996, Rapp et al., 1998), which consists of awareness training, competing response training, and social support. Unfortunately, evidence suggests that while effective at reducing pulling, HRT does not address the aversive cognitions and emotional states that often trigger pulling episodes (Woods et al., 2006). One factor that links emotions to pulling may be Psychological Inflexibility (PI), which is a generalized, maladaptive strategy used to regulate affect and unwanted cognitions resulting in reductions in meaningful life activities. Not to be confused with problems with cognitive flexibility (which involves the ability to shift attentional focus and does not appear to be dysfunctional in TTM; see Chamberlain et al. (2006)), PI involves problems in resisting maladaptive behaviors that are triggered by aversive cognitions and emotions (Hayes et al., 2006). PI has been associated with increased hair pulling severity and pulling urges (Begotka et al., 2004). Therefore, interventions that include techniques that target PI may be effective in reducing TTM symptoms.

Acceptance and Commitment Therapy (ACT; Hayes et al., 1999) is an empirically supported form of behavior therapy that attempts to reduce PI and increase individuals׳ engagement in valued behavior while also experiencing negative private events (e.g., not responding to the urge to pull hair because doing so takes one away from doing things more consistent with one׳s values). ACT has been found generally effective for a variety of mental health issues (Hayes et al., 2006), and components have been successfully incorporated into HRT for TTM (Twohig and Woods, 2004, Woods et al., 2006, Flessner et al., 2008a).

Psychological flexibility is thought to mediate successful outcomes in ACT (Ciarrochi et al., 2010) and is typically measured by the Acceptance and Action Questionnaire-II (AAQ-II; Bond et al., 2011). Because the AAQ-II is a general measure of PI, the measure׳s utility in clinical populations with specific psychopathologies can sometimes be limited. Thus, specific versions based on the AAQ-II have been created for diabetes (Gregg et al., 2007), epilepsy (Lundgren et al., 2008), substance abuse (Luoma et al., 2011), weight (Lillis and Hayes, 2008), cigarette smoking (Gifford et al., 2004), body image (Sandoz et al., 2013), chronic pain (McCraken et al., 2004), social anxiety (MacKenzie and Kocovski, 2010), tinnitus (Westin et al., 2008), and auditory hallucinations (Shawyer et al., 2007). These disorder-specific versions have shown increased precision for measuring PI in specific clinical and research contexts. For instance, when compared to the original measure, the AAQ for tinnitus more successfully predicted treatment outcomes (Westin et al., 2008), and the AAQ for substance abuse showed considerably stronger psychometric properties in its targeted population (Luoma et al., 2011).

Cognitive-affective variables, such as anxiety and mood, are linked to TTM (Diefenbach et al., 2002). According to ACT theory, it is the struggle to control inner experiences (i.e., avoidance) rather than the content of the experience itself (i.e., valence) that fuels psychological distress (Hayes et al., 1999). Individuals who are more psychologically inflexible would then be at risk for developing psychopathology in response to aversive inner experiences. Therefore, individuals with TTM might show a link between emotional variables and hair pulling that is mediated by PI, as has been reported in a previous study (Norberg et al., 2007). By extension, improving psychological flexibility through ACT or similar treatments could decrease pulling by making the behavior less susceptible to aversive inner experiences.

The current study examines the psychometric properties and mediational effects of a novel disorder-specific version of the AAQ for TTM. Specifically, it was hypothesized that the AAQ-TTM would demonstrate acceptable reliability and concurrent validity, adequate incremental validity over the AAQ-II on relevant indices, and potential utility as a process of change measure.