The relationship between different levels of cognition and behavioural symptoms in the eating disorders.

Background: Both disorder-specific cognitions and unconditional core beliefs have been associated with eating-disordered behaviours. This study examines whether these beliefs might provide competing or complementary explanations of those behaviours.

Method: The participants were 151 women with eating disorders. Each woman completed two self-report measures-the Eating Disorder Examination Questionnaire (measuring disorder-specific cognitions and reported behavioural frequency) and the Young Schema Questionnaire-Short version (measuring unconditional core beliefs). Objective height and weight were measured to give body mass index (BMI). Regression analyses were used to compare additive, mediator and moderator models of the cognition-behaviour link.

Results: BMI and reported frequency of vomiting were best explained by models where the impact of disorder-specific cognitions was moderated by unhealthy core beliefs, but where neither form of belief had an independent effect. In contrast, the frequency of reported objective binge-eating was best explained by an additive effect of the two forms of cognition.

Discussion: The findings indicate that both disorder-specific cognitions and unconditional core beliefs are necessary to explain the development and maintenance of disordered eating behaviours. This conclusion suggests that cognitive-behavioural approaches might be more effective if they address both levels of cognition. However, prospective research is required to confirm the causal hypothesis based on the present cross-sectional data.