Inhibitory learning approaches to exposure therapy: A critical review and translation to obsessive-compulsive disorder

The majority of treatment research on OCD has focused on pre/post treatment efficacy of exposure-based interventions, with less attention directed towards (a) understanding mechanisms of change, and (b) maximizing long-term effectiveness. Inhibitory learning theory (ILT) provides a novel foundation for understanding how exposure therapy reduces fear. Moreover, ILT is consistent with empirical evidence that raises questions about the more traditional (i.e., habituation) explanation for exposure therapy's efficacy. Yet ILT has yet to be applied to understanding the treatment of OCD and its heterogeneity. The current review is an examination of human experimental research on ILT that seeks to translate laboratory findings on fear extinction to exposure therapy across empirically established OCD symptom dimensions. We provide an up-to-date critical review of the existing evidence for a series of strategies derived from ILT that have been proposed for the treatment of fear, discuss the limitations of existing studies, and provide suggestions for future research within this rapidly accelerating area of study. We also offer conceptual considerations for applying these principles to the treatment of OCD symptom dimensions. A common theme is the idea of introducing "desirable difficulties" into the implementation of exposure in order to foster more durable long-term learning

Not Just Thinking, but Believing: Obsessive Beliefs and Domains of Cognitive Fusion in the Prediction of OCD Symptom Dimensions

Cognitive fusion (CF), involves the tendency to “buy in” to thoughts and feelings and consists of three empirically established domains: somatic concerns, emotion regulation, and negative evaluation. CF is hypothesized to play a role in obsessive-compulsive disorder (OCD). The present study examined how well the CF domains, relative to traditional cognitive-behavioral constructs (i.e., obsessive beliefs such as inflated responsibility), predict OCD symptoms. 52 treatment-seeking adults with OCD completed self-report measures of CF, obsessive beliefs, OCD symptoms, and general distress. Domains of CF were differentially associated with the responsibility for harm, symmetry and unacceptable thoughts OCD dimensions, yet after accounting for obsessive beliefs, only the negative evaluation domain of CF significantly predicted symmetry OCD symptoms. Obsessive beliefs significantly predicted all OCD dimensions except for contamination. These findings provide additional support for existing cognitive-behavioral models of OCD across symptom dimensions, with the exception of contamination symptoms, and suggest that the believability of thoughts and feelings about negative evaluation adds to the explanation of symmetry symptoms. Conceptual and treatment implications, study limitations, and future directions are discussed

Bulk phase behaviour of binary hard platelet mixtures from density functional theory

We investigate isotropic-isotropic, isotropic-nematic and nematic-nematic phase coexistence in binary mixtures of circular platelets with vanishing thickness, continuous rotational degrees of freedom and radial size ratios $\lambda$ up to 5. A fundamental measure density functional theory, previously used for the one-component model, is proposed and results are compared against those from Onsager theory as a benchmark. For $\lambda \leq 1.7$ the system displays isotropic-nematic phase coexistence with a widening of the biphasic region for increasing values of $\lambda$. For size ratios $\lambda \geq 2$, we find demixing into two nematic states becomes stable and an isotropic-nematic-nematic triple point can occur. Fundamental measure theory gives a smaller isotropic-nematic biphasic region than Onsager theory and locates the transition at lower densities. Furthermore, nematic-nematic demixing occurs over a larger range of compositions at a given value of $\lambda$ than found in Onsager theory. Both theories predict the same topologies of the phase diagrams. The partial nematic order parameters vary strongly with composition and indicate that the larger particles are more strongly ordered than the smaller particles

The Relative Contributions of Experiential Avoidance and Distress Tolerance to OC Symptoms

Background: Obsessive beliefs account for substantial (but not all) obsessive-compulsive (OC) symptoms. Intolerance of internal experiences (IIE), which encompasses the constructs of experiential avoidance (EA) and distress tolerance (DT), refers to difficulty managing unwanted thoughts, emotions, and other internal states, and might add to current explanatory models. Although IIE appears to be conceptually relevant to obsessive-compulsive (OC) symptoms, scant research has examined this relationship empirically. Aim: The present study examined the relative contributions of EA and DT as predictors of OC symptom dimensions. Method: A nonclinical sample ( n = 496) completed self-report questionnaires measuring general distress, EA, DT and OC symptom dimensions. Results: All variables of interest were significantly (all p s ≤ .001) correlated with one another, such that higher general distress, higher EA, and lower DT were associated with greater OC symptom severity for all symptom dimensions; however, only EA independently predicted obsessional symptoms, but not other OC symptom dimensions. Conclusions: One's willingness to endure (i.e. EA), rather than their ability to tolerate (i.e. DT) unpleasant internal experiences best predicts obsessional symptoms (i.e. obsessing) above and beyond general distress. Potential implications for understanding, assessing, and treating OC symptoms are discussed

Study of multi black hole and ring singularity apparent horizons

We study critical black hole separations for the formation of a common apparent horizon in systems of $N$ - black holes in a time symmetric configuration. We study in detail the aligned equal mass cases for $N=2,3,4,5$, and relate them to the unequal mass binary black hole case. We then study the apparent horizon of the time symmetric initial geometry of a ring singularity of different radii. The apparent horizon is used as indicative of the location of the event horizon in an effort to predict a critical ring radius that would generate an event horizon of toroidal topology. We found that a good estimate for this ring critical radius is $20/(3\pi) M$. We briefly discuss the connection of this two cases through a discrete black hole 'necklace' configuration.Comment: 31 pages, 21 figure

Semi-relativistic approximation to gravitational radiation from encounters with nonspinning black holes

The capture of compact bodies by black holes in galactic nuclei is an important prospective source for low frequency gravitational wave detectors, such as the planned Laser Interferometer Space Antenna. This paper calculates, using a semirelativistic approximation, the total energy and angular momentum lost to gravitational radiation by compact bodies on very high eccentricity orbits passing close to a supermassive, nonspinning black hole; these quantities determine the characteristics of the orbital evolution necessary to estimate the capture rate. The semirelativistic approximation improves upon treatments which use orbits at Newtonian-order and quadrupolar radiation emission, and matches well onto accurate Teukolsky simulations for low eccentricity orbits. Formulae are presented for the semirelativistic energy and angular momentum fluxes as a function of general orbital parameters.Comment: 27 pages, 12 figures; v2: revised manuscript includes small changes to make paper consistent with published version; v3: a statement about how to generalise our results to hyperbolic orbits was incorrect, new version includes published erratum as an appendi

Anxiety sensitivity as a predictor of outcome in the treatment of obsessive-compulsive disorder

BACKGROUND AND OBJECTIVES: To address the fact that not all individuals who receive cognitive-behavioral therapy (CBT) for obsessive-compulsive disorder (OCD) exhibit complete symptom reduction, research has examined factors that predict outcome; however, no studies have examined anxiety sensitivity (AS) as a predictor of outcome of CBT for OCD. AS refers to the fear of anxious arousal that results from mistaken beliefs about the dangerousness of anxiety-related body sensations. It is important to understand whether AS influences OCD treatment outcome, considering that (a) some obsessions directly relate to AS, and (b) OCD patients with high AS may be reluctant to engage in anxiety-provoking components of CBT for OCD. METHODS: Patients (N = 187) with a primary diagnosis of OCD who received residential CBT for OCD participated in this study, which involved completing a self-report battery at pre- and post-treatment. RESULTS: Results supported study hypotheses, in that (a) baseline AS positively correlated with baseline OCD severity, and (b) greater baseline AS prospectively predicted higher posttreatment OCD symptom severity even after controlling for pretreatment OCD and depression severity. LIMITATIONS: The study was limited by its use of an older measure of AS, reliance on self-report measures, and nonstandardized treatment across participants. CONCLUSIONS: Findings highlight the importance of AS in the nature and treatment of OCD. Clinical implications and future directions are discussed

Enhancing the ecological validity of the Beads Task as a behavioral measure of intolerance of uncertainty

To broaden the measurement of intolerance of uncertainty (IU) beyond self-report methods, recent research has examined the Beads Task as a behavioral measure of IU. In the present study, we enhanced this task to increase its ecological validity by maximizing decisional uncertainty and the importance of a correct response. Undergraduate participants (n=102) completed the Beads Task with instructions that they would complete the Cold Pressor Task (CPT) if they answered incorrectly. As hypothesized, baseline CPT endurance time and self-reported pain level were weakly associated with later Beads Task distress during the decision-making process. Furthermore, in vivo Beads Task distress was associated with self-report inhibitory IU, which measures avoidance and paralysis in the face of uncertainty, but not with prospective IU, perfectionism, or general psychological distress after making statistical adjustments for multiple comparisons. Comparisons to previous work using the Beads Task, clinical implications, and avenues for future research are discussed

Moderators and Processes of Change in Traditional Exposure and Response Prevention (ERP) Versus Acceptance and Commitment Therapy-Informed ERP for Obsessive-Compulsive Disorder

The present study evaluated moderators and processes of change in a randomized controlled trial comparing exposure and response prevention (ERP) delivered from a traditional framework versus ERP from an acceptance and commitment therapy framework (ACT+ERP) for obsessive-compulsive disorder (OCD). This paper presents baseline, weekly session, posttreatment, and follow-up data from the study. We examined (a) moderation effects of anxiety, depression, psychological inflexibility, and interpretation of intrusions and (b) the role of psychological inflexibility and interpretation of intrusions respectively as processes of change. Participants with less dysfunctional appraisals at pretreatment performed consistently better in ERP relative to ACT+ERP. In process analyses, psychological inflexibility and interpretation of intrusions positively influenced OCD severity over time in both conditions but OCD symptom severity also positively influenced psychological inflexibility and interpretation of intrusions in both conditions. Furthermore, whereas OCD symptom severity strongly and positively predicted dysfunctional appraisals over the course of treatment in ERP, symptom severity had a weaker positive effect on dysfunctional appraisals in ACT+ERP. Clinical and theoretical implications as well as study limitations are discussed

Sensory intolerance: Latent structure and psychopathologic correlates

Sensory intolerance refers to high levels of distress evoked by everyday sounds (e.g., sounds of people chewing) or commonplace tactile sensations (e.g., sticky or greasy substances). Sensory intolerance may be associated with obsessive-compulsive (OC) symptoms, OC-related phenomena, and other forms of psychopathology. Sensory intolerance is not included as a syndrome in current diagnostic systems, although preliminary research suggests that it might be a distinct syndrome