Overprediction of fear in panic disorder patients with agoraphobia: does the (mis)match model generalize to exposure in vivo therapy?

Does prediction error during exposure relate to clinical outcomes in cognitive behavior therapy for social anxiety disorder? A study protocol

Facing your fears, or exposure therapy, is an effective psychological intervention for anxiety disorders that is often thought to work through fear extinction learning. Fear extinction learning is a type of associative learning where fear reduces through repeated encounters with a feared situation or stimulus in the absence of aversive outcomes. Laboratory research suggests fear extinction learning is driven by threat prediction errors, defined as when fearful predictions do not eventuate. Threat prediction error and its relationship to exposure therapy outcomes haven't been studied enough in actual therapy settings. It remains unclear whether prediction error and extinction learning are central mechanisms of exposure therapy. We are conducting a longitudinal and observational study of how threat prediction error during exposure in social anxiety disorder (SAD) treatment relates to session-by-session symptom change and treatment outcome in addition to exposure surprise and learning outcome. We aim to recruit 65 adults with a primary diagnosis of SAD through an outpatient psychology clinic. Participants will receive 12 sessions of individual manualized cognitive behavioral therapy (CBT), adapted from an efficacious group protocol, that includes graded exposure. Exposure processes, including self-report measures of anxiety, threat prediction, threat outcomes, surprise, and learning outcome, will be measured with smartphone-based event-contingent ecological momentary assessments (EMAs) of all behavioral experiments completed during treatment. Clinical outcomes include self-reported social anxiety symptoms and social threat appraisals, at each session, post and 3-months after treatment. Prediction error will be operationalized as the mismatch between the threat prediction and threat outcome. The joint effect of threat prediction and threat outcome on session-by-session symptom change, treatment outcome, exposure surprise, and learning outcome will be explored using multilevel modeling. The present study will help determine whether threat prediction error during exposures in SAD treatment is related to theoretically implied clinical outcomes. This would contribute to the larger research aim of clarifying exposure therapy mechanisms.

Mechanisms of exposure and response prevention in obsessive-compulsive disorder: effects of habituation and expectancy violation on short-term outcome in cognitive behavioral therapy

BACKGROUND

Exposure and response prevention is effective and recommended as the first choice for treating obsessive-compulsive disorders (OCD). Its mechanisms of action are rarely studied, but two major theories make distinct assumptions: while the emotional processing theory assumes that treatment effects are associated with habituation within and between exposure sessions, the inhibitory learning approach highlights the acquisition of additional associations, implying alternative mechanisms like expectancy violation. The present study aimed to investigate whether process variables derived from both theories predict short-term outcome.

METHOD

In a university outpatient unit, 110 patients (63 female) with OCD received manual-based cognitive-behavioral therapy with high standardization of the first two exposure sessions. Specifically, therapists repeated the first exposure session identically and assessed subjective units of distress as well as expectancy ratings in the course of exposure sessions. Based on these data, individual scores for habituation and distress-related expectancy violation were calculated and used for prediction of both percentage change on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and remission status after 20 therapy sessions.

RESULTS

In a multiple regression model for percentage change, within-session habituation during the first exposure was a significant predictor, while in a logistic regression predicting remission status, distress-related expectancy violation during the first exposure revealed significance. A path model further supported these findings.

CONCLUSIONS

The results represent first evidence for distress-related expectancy violation and confirm preliminary findings for habituation, suggesting that both processes contribute to treatment benefits of exposure in OCD, and both mechanisms appear to be independent.

That Was Easy! Expectancy Violations During Exposure and Response Prevention for Childhood Obsessive-Compulsive Disorder

Violating expectancies during exposure therapy is proposed to promote inhibitory learning and improved treatment outcomes. Because people tend to overestimate how distressing emotionally challenging situations will be, violating expectations of distress may be an intuitive way to promote treatment outcome during exposure-based cognitive-behavioral therapy (CBT). This study evaluated overpredictions of distress during exposure tasks in 33 youth with obsessive-compulsive disorder (OCD; ages 8-17) participating in CBT. Youth with more variable prediction accuracy and a higher proportion of overpredictions experienced more rapid symptom reduction, b = -0.29, p = .002. Underpredictions were less common toward the end of therapy as youth experienced less severe OCD, b = 0.12, p= .001. Findings suggest that although youth often accurately predict the intensity of exposure, overpredictions are common as well. The frequency of these overpredictions promoted treatment outcome, supporting expectancy violations as one indicator of inhibitory learning during exposure therapy.

Exposure and response prevention process predicts treatment outcome in youth with OCD

Recent research on the treatment of adults with anxiety disorders suggests that aspects of the in-session exposure therapy process are relevant to clinical outcomes. However, few comprehensive studies have been conducted with children and adolescents. In the present study, 35 youth diagnosed with primary obsessive-compulsive disorder (OCD; M age = 12.9 years, 49% male, 63% Caucasian) completed 12 sessions of exposure and response prevention (ERP) in one of two treatment conditions as part of a pilot randomized controlled testing of a family focused intervention for OCD. Key exposure process variables, including youth self-reported distress during ERP and the quantity and quality of ERP completed, were computed. These variables were examined as predictors of treatment outcomes assessed at mid-treatment, post-treatment, and three-month follow-up, partialing treatment condition. In general, greater variability of distress during ERP and completing a greater proportion of combined exposures (i.e., exposures targeting more than one OC symptom at once) were predictive of better outcomes. Conversely, greater distress at the end of treatment was generally predictive of poorer outcomes. Finally, several variables, including within- and between-session decreases in distress during ERP, were not consistently predictive of outcomes. Findings signal potentially important facets of exposure for youth with OCD and have implications for treatment. A number of results also parallel recent findings in the adult literature, suggesting that there may be some continuity in exposure processes from child to adult development. Future work should examine additional measures of exposure process, such as psychophysiological arousal during exposure, in youth.

Pharmacogenetic excitation of dorsomedial prefrontal cortex restores fear prediction error

Pavlovian conditioning involves encoding the predictive relationship between a conditioned stimulus (CS) and an unconditioned stimulus, so that synaptic plasticity and learning is instructed by prediction error. Here we used pharmacogenetic techniques to show a causal relation between activity of rat dorsomedial prefrontal cortex (dmPFC) neurons and fear prediction error. We expressed the excitatory hM3Dq designer receptor exclusively activated by a designer drug (DREADD) in dmPFC and isolated actions of prediction error by using an associative blocking design. Rats were trained to fear the visual CS (CSA) in stage I via pairings with footshock. Then in stage II, rats received compound presentations of visual CSA and auditory CS (CSB) with footshock. This prior fear conditioning of CSA reduced the prediction error during stage II to block fear learning to CSB. The group of rats that received AAV-hSYN-eYFP vector that was treated with clozapine-N-oxide (CNO; 3 mg/kg, i.p.) before stage II showed blocking when tested in the absence of CNO the next day. In contrast, the groups that received AAV-hSYN-hM3Dq and AAV-CaMKIIα-hM3Dq that were treated with CNO before stage II training did not show blocking; learning toward CSB was restored. This restoration of prediction error and fear learning was specific to the injection of CNO because groups that received AAV-hSYN-hM3Dq and AAV-CaMKIIα-hM3Dq that were injected with vehicle before stage II training did show blocking. These effects were not attributable to the DREADD manipulation enhancing learning or arousal, increasing fear memory strength or asymptotic levels of fear learning, or altering fear memory retrieval. Together, these results identify a causal role for dmPFC in a signature of adaptive behavior: using the past to predict future danger and learning from errors in these predictions.

The mediational role of panic self-efficacy in cognitive behavioral therapy for panic disorder: a systematic review and meta-analysis

Cognitive models of panic disorder (PD) with or without agoraphobia have stressed the role of catastrophic beliefs of bodily symptoms as a central mediating variable of the efficacy of cognitive behavioral therapy (CBT). Perceived ability to cope with or control panic attacks, panic self-efficacy, has also been proposed to play a key role in therapeutic change; however, this cognitive factor has received much less attention in research. The aim of the present review is to evaluate panic self-efficacy as a mediator of therapeutic outcome in CBT for PD using descriptive and meta-analytic procedures. We performed systematic literature searches, and included and evaluated 33 studies according to four criteria for establishing mediation. Twenty-eight studies, including nine randomized waitlist-controlled studies, showed strong support for CBT improving panic self-efficacy (criterion 1); ten showed an association between change in panic self-efficacy and change in outcome during therapy (criterion 2); three tested, and one established formal statistical mediation of panic self-efficacy (criterion 3); while four tested and three found change in panic self-efficacy occurring before the reduction of panic severity (criterion 4). Although none of the studies fulfilled all of the four criteria, results provide some support for panic self-efficacy as a mediator of outcome in CBT for PD, generally on par with catastrophic beliefs in the reviewed studies.

Power law relationships between health care utilization and symptom assessment among people with panic attacks

RATIONALE

Although people with panic attacks are high utilizers of health care, the role of symptom assessment in care-seeking is unclear. Previous studies suggest that symptom perceptions are linearly related to utilization but panic appraisal is not. The purpose of this study was to determine whether the relationships between symptom assessment and utilization are non-linear, displaying power law distributions.

METHODS

This community-based study of 97 subjects with panic attacks assessed utilization of family doctor offices, total ambulatory utilization, and hospitalizations as well as symptom perceptions and panic appraisals. Matrices of symptom assessment versus utilization were created, and log-log plots were constructed. To minimize the risk of overestimation of power law distributions, linear, quadratic and cubic regression models were computed.

RESULTS

None of the utilization versus symptom perceptions displayed power law distributions. However, all three measures of utilization showed power law relationships with panic appraisals, but in unique patterns.

CONCLUSIONS

Although power law relationships were not found between symptom perceptions and utilization, unique patterns of power laws were identified between panic appraisals and all three measures of utilization.

UCS expectancy biases in spider phobics: underestimation of aversive consequences following fear-irrelevant stimuli

This paper reports the results of two studies investigating judgements made by spider phobics about the potential threatening consequences (unconditioned stimulus, UCS, expectancies) associated with their phobic stimulus, fear-relevant (FR) stimuli, and fear-irrelevant (FI) stimuli. Using a 'thought experiment' UCS expectancy paradigm, the studies reported found that (1) spider phobics reported significantly higher UCS expectancies to spider stimuli than nonphobics, (2) spider phobics consistently underestimated the probability of aversive consequences following FI stimuli and (3) this underestimation of UCS expectancies to FI stimuli in phobics was not the result of a contrast effect resulting from sequential FR and FI judgements. This differential effect may have important implications for the kind of mechanism which mediates judgements about phobic consequences. These findings suggest that the dimensions on which phobic stimuli are categorised may be 'stretched' in the case of phobics and that this gives rise to the comparative underestimation of threat associated with FI stimuli but also makes phobics more vulnerable to acquiring other phobias.

Stimulus estimation and the overprediction of fear: a comment on two studies

The overprediction of fear is the tendency to overestimate the amount of fear one will experience in a subjectively threatening situation. This bias is thought to promote excessive avoidance and limit the opportunity for corrective learning. The stimulus estimation model states that the overprediction of fear arises from the overprediction of the danger features of the stimulus and the underprediction of available safety resources. Two recent studies reportedly failed to support the model (Arntz, Hildebrande & van den Hout, Behaviour Research and Therapy, 32, 709-722, 1994; Telch, Valentiner & Bolte, Behaviour Research and Therapy, 32, 747-751, 1994). The present commentary shows that both studies suffered significant methodological problems and neither can be said to have tested the model. Criteria for evaluating the model are briefly discussed.