Measuring Extinction Learning across the Lifespan – Adaptation of an optimized paradigm to closely match exposure treatment procedures

Targeting intolerance of uncertainty in treatment: A meta-analysis of therapeutic effects, treatment moderators, and underlying mechanisms

OBJECTIVE

Anxiety-related disorders are among the most prevalent psychiatric conditions and cause significant impairment. Intolerance of uncertainty (IU) contributes to the emergence, maintenance, and symptom severity of anxiety-related disorders, yet information regarding treatment-related changes in IU is limited. This systematic review and meta-analysis examined the efficacy of evidence-based treatments for anxiety-related disorders on IU, explored factors moderating treatment effects of IU, and examined whether therapeutic improvement in IU corresponded with improvements in anxiety symptom severity.

METHODS

PubMED and PsycINFO were searched for randomized controlled trials (RCTs) using the terms "intolerance of uncertainty" AND "treatment" OR "therapy." Data for pre and post-treatment measures and patient, intervention, and trial-level characteristics were extracted from 28 RCTs. Separate random effects models examined the treatment efficacy of interventions on IU and symptom severity. Moderators of therapeutic effects were analyzed via method-of-moments meta-regression or an analog to the analysis of variance.

RESULTS

Across RCTs, interventions exhibited a large therapeutic effect on IU compared to control conditions (g = 0.89). Treatment effects on IU positively corresponded with improved symptom severity and accounted for 36 % of the variance. Interestingly, comorbid depression and certain treatment approaches were associated with larger improvements in IU.

CONCLUSION

Evidence-based treatments are effective in improving IU, highlighting the importance of IU in the treatment of anxiety-related disorders. Moderator analyses identified patient and intervention-level factors to inform approaches to improve therapeutic effects on IU. Future research is needed to optimize interventions targeting IU and evaluate long-term efficacy of interventions on IU for anxiety-related disorders.

Getting Better with Age? A Review of Psychophysiological Studies of Fear Extinction Learning Across Development

A critical developmental task is learning what constitutes reliable threat and safety signals in the environment. In humans, atypical fear learning processes are implicated in many mental health conditions, particularly fear and anxiety disorders, pointing to the potential for laboratory measures of fear learning to facilitate early identification of at-risk individuals. This chapter reviews studies of fear learning and extinction learning that incorporate peripheral measures of psychophysiological response and include a developmental sample. Broadly, these studies indicate substantial consistency in differential learning and extinction across development, as assessed with multiple paradigms, across physiological indices. Importantly, though, response coherence across measures (e.g., physiological, neural, and behavioral) was inconsistent across studies. There was also less consistency in results from studies that probed associations between anxiety and fear learning processes. These mixed findings highlight the need for additional examination of when and why there is variability, both across development and in relation to individual differences factors, including mental health, childhood adversity, and sex. In addition, there remains a need for studies that test for developmental change in extinction recall learning and whether stimulus type impacts learning across development. Longitudinal studies designed to address these questions could provide novel insight into the developmental trajectory of fear learning and extinction.

Understanding Human Fear Extinction: Insights from Psychophysiology

The study of fear extinction has been driven largely by Pavlovian fear conditioning methods across the translational spectrum. The primary methods used to study these processes in humans have been recordings of skin conductance (historically termed galvanic skin response) and fear-potentiation of the acoustic startle reflex. As outlined in the following chapter, the combined corpus of this work has demonstrated the value of psychophysiology in better understanding the underlying neurobiology of extinction learning in healthy humans as well as those with psychopathologies. In addition, psychophysiological approaches, which allow for the preservation of methods between species, have shown their applicability to the assessment of wide-ranging treatment effects. The chapter concludes with potential trajectories for future study in this area.

Test–retest reliability of human threat conditioning and generalization across a 1‐to‐2‐week interval

Given the increasing use of threat conditioning and generalization for clinical-translational research efforts, establishing test-retest reliability of these paradigms is necessary. Specifically, it is an empirical question whether the same participant evinces a similar generalization gradient of conditioned responses across two sessions with the identical contingencies and stimuli. Here, 46 human volunteers participated in an identical auditory threat acquisition and generalization protocol at two sessions separated by 1-to-2 weeks. Skin conductance responses (SCR) and trial-by-trial shock risk ratings served as primary measures. We used linear mixed effects modeling to test differential threat responses and generalization gradients, and Generalizability (G) theory coefficients as our primary formal assessment of test-retest reliability of intraindividual stability and change across time. Results showed largely invariant differential conditioning and generalization gradients across time. G coefficients indicated fair reliability for acquisition and generalization SCR. In contrast, risk rating reliabilities were mixed, and reliability was particularly low for acquisition risk ratings. Our findings generally support reliability of the threat conditioning and generalization paradigm for shorter test-retest intervals and highlight their utility for assessments of behavioral interventions in mental health research, but challenges remain and further work is needed. Threat conditioning and generalization tasks are increasingly used for translational efforts to improve behavioral interventions, and thus test-retest reliability for these tasks needs to be established. Our results support the test-retest reliability of threat conditioning and generalization over a relatively short (1-to-2 week) interval, but this depends on the measure used (physiological vs. self-report). Overall, these tasks could be appropriate for repeated testing over the course of a short-duration intervention study, but more research is needed, particularly in regard to longer-duration studies.