Exposure therapy seems to work well for anxiety disorders, as well as for eating disorders and obesity. However, according to recent insights, the mode of delivery of exposure would be of great importance for treatment success: instead of focusing on fear/craving habituation, sessions should be aimed at maximizing inhibitory learning. One way to strengthen inhibitory learning is to violate expectations during exposure. In several studies, we examined the relationship between craving habituation/expectancy violation and treatment outcome during cue exposure therapy. 176 subjects were included (cue exposure n = 96, control n = 80); 16 men and 160 women. 148 subjects (84.1%) met the criterion for obesity (BMI > 30), the remaining 28 subjects (15.9%) were overweight (BMI > 25). Of the 96 subjects in the cue exposure condition, 21 subjects received one session, 56 subjects received two sessions, and 19 subjects received eight sessions of exposure therapy. Food cravings were monitored throughout the sessions, and expectations about loss of control were measured via self-report before and after therapy. For both measures, the association with overeating was investigated, measured in a behavioral task in the laboratory.
The results showed that habituating cravings during and between exposure sessions were not associated with overeating after cue exposure. However, the greater the violation of expectations about loss of control during cue exposure, the fewer subjects overate at the end of therapy. Cue exposure appears to be effective in reducing overeating, and the degree of this success appears to be related in part to the violations of expectations about loss of control during cue exposure. Although cravings often decrease during cue exposure sessions, this does not seem to correlate with better therapy outcome, at least with regard to overeating.