Challenges to the traditional exposure paradigm: variability in exposure therapy for contamination fears

J Behav Ther Exp Psychiatry. 2012 Jun;43(2):745-51. doi: 10.1016/j.jbtep.2011.10.010. Epub 2011 Nov 2.


Background and objectives: Traditional models and methods of exposure therapy utilize a fear hierarchy, whereby patients complete sets of exposures in a graduated manner, with the goal of fear habituation within and between sessions. In the current experiment, we examined whether this typical exposure paradigm was necessary to achieve clinical improvement.

Method: Fifty undergraduate participants scoring in the top quartile of a self-report measure of contamination fears were randomly assigned to one of two groups: blocked and constant exposure (BC Group) and random and variable exposure (RV Group). Both groups completed three weekly sessions of exposure treatment, with subjective and psychophysiological indices of fear recorded throughout. Subjective, behavioral, and psychophysiological dependent measures were evaluated by an independent assessor at pre-treatment (PRE), post-treatment (POST), and two-week follow-up (2WFU).

Results: Both the BC Group and RV Group exhibited decreases in subjective fear from PRE to POST and 2WFU, with no significant differences between groups. Partialing group, greater variability in subjective fear during exposure predicted lower subjective fear at 2WFU.

Limitations: Despite significant findings for subjective fear, behavioral and psychophysiological findings were limited. Follow-up studies should investigate questions regarding traditional exposure within a clinical group.

Conclusions: These results support the notion that traditional exposure is sufficient, but not necessary, to produce clinical improvement in contamination-related fears. There may be benefits to variability in fear level during exposure, and evaluation of emotion variability during exposure therapy for other anxiety disorders is warranted.

MeSH terms

  • Adolescent
  • Analysis of Variance
  • Chi-Square Distribution
  • Fear*
  • Female
  • Galvanic Skin Response / physiology
  • Heart Rate / physiology
  • Humans
  • Implosive Therapy / methods*
  • Male
  • Phobic Disorders / physiopathology
  • Phobic Disorders / psychology*
  • Phobic Disorders / rehabilitation*
  • Psychiatric Status Rating Scales
  • Self Report
  • Treatment Outcome
  • Young Adult