Prognostic value of autonomous and controlled motivation in outpatient eating-disorder treatment

According to Self-Determination Theory, when motivation to reach an objective is fully internal, it is said to be "autonomous"; when driven by external incentives, it is said to be "controlled". Previous research has indicated that autonomously motivated individuals show better response to treatments for eating disorders.

In individuals undergoing different intensities of outpatient treatment for an eating disorder, we sought to assess associations between autonomous and controlled motivations and response to treatment on the one hand, and likelihood of dropping out of treatment, on the other.

Seven hundred seventy adults meeting DSM-5 criteria for an eating disorder (216 with Anorexia Nervosa, 282 with Bulimia Nervosa, and 272 with Other Specified Feeding or Eating Disorder) were included in this study. Before an interval of outpatient treatment, individuals completed the Eating Disorder Examination Questionnaire and the Autonomous and Controlled Motivations for Treatment Questionnaire. Participants completed the Eating Disorder Examination Questionnaire again at one or two subsequent timepoints.

After controlling for diagnosis, treatment intensity, and number of previous treatments, analyses showed that higher autonomous motivation was associated with better response on eating-disorder overall symptoms and lower likelihood of dropping out of treatment. In contrast, controlled motivation was not associated with response to treatment.

Our results suggest that autonomous motivation has trans-diagnostic influence upon response to various intensities of treatment for an eating disorder. In support of an autonomy supportive approach to treatment, findings link autonomous motivation with more favorable outcome.