Does Self-Efficacy at the Start of Treatment Influence Treatment Outcome in Patients With EDs?

Eating disorders (EDs) are severe psychiatric disorders, characterized by a persistent disturbance of eating which impairs health or psychosocial functioning and causes loss of quality of life. There are several evidence-based forms of treatment, but outcomes are mediocre at best. Previous research found better treatment outcomes with several baseline predictors, such as greater motivation to recover. Research on motivation to change has indicated that autonomous motivated (AM) individuals show better response to treatments for EDs. However, being highly motivated for change, but not experiencing the capacity to really eat more and to deal with the emotions evoked by the process of recovery, might lead to difficulty to change key-behaviors, thus leading to less positive treatment outcome. Several researchers emphasized the importance of self-efficacy as a predictor in eating attitudes and behaviors. This study focuses on whether self-efficacy at the start of treatment is predictive of treatment outcome, measured by the ED-15 questionnaire in patients with an ED. Data will be obtained during CBT-T; a brief (10 sessions) version of cognitive behavioral therapy for eating disorders like BN, BED and OSFED. In CBT-T patients are encouraged, from the start of treatment, to challenge their fears, experience the effect of exposure and motivating them to carry through. This aspect might enlarge patients' experience of self-efficacy. Patients with low level of self-efficacy at start, but higher level of self-efficacy after four sessions, might benefit better from treatment, then patients with lower levels of self-efficacy throughout the treatment. To study this potential effect of treatment on self-efficacy, self-efficacy will be measured at start of treatment, at session four and at the end of treatment.

Self-efficacy, self-esteem and autonomous motivation are concepts that are closely linked to each other. To test if they are positively correlated at start of treatment, measurements covering these concepts will be included at T0.

HYPOTHESES

Primary hypotheses:

Higher levels of self-efficacy will positively predict a more positive treatment outcome as determined by lower eating pathology levels with the ED-15.

Secondary hypotheses:

• Self-efficacy in itself will improve during treatment.
• Autonomous motivation, self-esteem and self-efficacy will be positively correlated.

Patients are eligible for participation when they meet the following inclusion criteria:

• Participants must be 18 years or older
• Having an eating disorder diagnosed according to the Diagnostic Statistical Manual (DSM-5)
• Starting CBT-T treatment

Exclusion criteria

• Intellectual disability according to the Diagnostic Statistical Manual (DSM-5) or an IQ below 80
• Inability to speak or read Dutch
• Patients treated under a legal act