Verbal, behavioural and physiological assessment of the generalization of exposure-based fear reduction in a spider-anxious population

The relative efficacy and efficiency of single- and multi-session exposure therapies for specific phobia: A meta-analysis

Exposure therapy is the preferred treatment for specific phobia (SP), with evidence supporting its efficacy whether delivered over multiple sessions or as a single session, such as One-Session Treatment. In this meta-analysis, we compared the efficiency and effectiveness of single- and multi-session exposure for SP. PsycINFO, Embase, MEDLINE, and Cochrane were systematically searched for peer-reviewed articles reporting the effects of multi-session (k = 30) and/or single-session (k = 55) in vivo exposure on SP symptoms in clinical populations (n = 1758 participants). A random-effects model was used to synthesise and compare the pre-post treatment effects (Hedges' g) on approach behaviour and self-reported SP symptoms. Mean total treatment time was significantly longer for multi-session exposure than for single-session. There were no significant differences in the pooled effect sizes of single-session and multi-session exposure at post-treatment and follow-up assessments; effect sizes were large for all outcomes. Phobia subtype significantly moderated the effect size for both treatment approaches, although the direction of association differed according to the outcome measures. Results suggest no evidence for differences in the effectiveness of single- and multi-session exposure, but single-session is more time efficient. These outcomes suggest that policies to facilitate access to single-session exposure would be beneficial.

Context and renewal of conditioned fear: an experimental evaluation using 20% carbon dioxide-enriched air as an unconditioned stimulus

This analogue experiment used fear conditioning and extinction procedures to establish and reduce fearful responding and then test for fear renewal following a context change. Healthy undergraduates (N=61) underwent a differential fear conditioning procedure using geometric shapes as conditioned stimuli (CS) and inhalations of 20% CO(2)-enriched air as an aversive unconditioned stimulus (US). Across phases (i.e., habituation, acquisition, extinction, and test), red and green ambient lighting served as contextual stimuli, and electrodermal and evaluative ratings were assessed as indices of conditioned fear. The control group underwent extinction and test phases under identical conditions (i.e., no context changes). The experimental groups either underwent acquisition and test phases in one context and the intervening extinction phase in a different context (A-B-A), or underwent acquisition and extinction phases in one context and the test phase in a novel context (A-A-B). Consistent with expectation, fear renewal was observed when the test context matched the acquisition context. This effect was modest for electrodermal responses, but reasonably robust for evaluative responses. The role of context in the subsequent renewal of fear following exposure-based treatment is discussed.

Relapse of successfully treated anxiety and fear: theoretical issues and recommendations for clinical practice

Despite the existence of effective interventions for anxiety disorders, relapse--or the return of fear--presents a significant problem for patients and clinicians in the longer term. The present paper draws on the experimental and clinical behavioural literature, reviewing the mechanisms by which the return of fear can occur. The aim of the paper was to generate a list of treatment recommendations for clinicians aimed at reducing relapse in successfully treated anxiety disorders. Clinical and experimental literature on the mechanisms of renewal, reinstatement, spontaneous recovery and reacquisition are reviewed. These are linked with the clinical and experimental literature on the return of fear in successfully treated anxiety. A list of recommendations to assist in reducing the probability of relapse in successfully treated anxiety is presented. This list includes methods for use in behavioural (exposure) treatment of anxiety disorders that aim to enhance clinical outcomes. Despite the significant problem of relapse in successfully treated anxiety, there are methods available to reduce the probability of relapse through return of fear. Clinicians engaging in treatment of anxiety disorders should be mindful of these methods to ensure optimal patient outcome.