Clinical and Cost-effectiveness of Group Schema Therapy for Complex Eating Disorders: the GST-EAT Study

Maastricht University

Status: Enrolling

Conditions: Bulimia Nervosa; Atypical Anorexia Nervosa (Other Specified Eating Disorder); Atypical Bulimia Nervosa (Other Specified Eating Disorder); Anorexia Nervosa

Treatments: Behavioral: GST; Behavioral: CBT-E

Study type: Interventional

Funder types: Other

Identifiers

NCT05812950

NL80491.068.22

60-63600-98-1131 (Registry Identifier)

Details and patient eligibility

About

Amongst psychiatric illnesses, eating disorders (EDs) are notoriously difficult to treat and have a high mortality rate. The average duration of an ED is 6 years and for a majority of ED patients, the disorder will become chronic. Comorbid personality pathology such as negative core beliefs and early maladaptive schemas (EMS) are strongly related to ED severity and chronicity. Enhanced cognitive-behavioural therapy for eating disorders (CBT-E) is used as the first line transdiagnostic treatment for EDs. However, CBT-E is mainly symptom-focused and does not tap into these underlying core beliefs and EMS.

Given the limited treatment effects of existing ED treatments, and the importance of comorbid personality pathology, there is an urgent need to examine more effective treatments for EDs. Group-schematherapy (GST) overcomes the limitations of CBT-E and preliminary results for treatment-resistant EDs are promising. However, robust evidence regarding the clinical and cost-effectiveness of GST for patients that do not benefit from CBT-E is not yet available. The central aim of this project is to investigate the clinical and cost-effectiveness of GST for EDs in patients with comorbid personality pathology, who do not show a clinically significant response in the first phase of CBT-E. This is relevant and important as studies examining the effectiveness of GST for EDs are scarce. This project is a joint research initiative of three academic centers (Dutch Universities), four large nation-wide mental health organizations, and two foundations for client empowerment and participation. Eligible patients will be randomized to either GST or continuation of their CBT-E treatment after failing to show a significant treatment response in the first phase of CBT-E. Based on encouraging findings from previous studies and our own pilot data, a statistically and clinically significant better outcome in terms of ED symptoms, negative core beliefs, EMS, schema modes, and quality of life is expected in the GST group compared to the CBT-E group. GST is also expected to be more cost-effective compared to CBT-E as GST may in the long run prevent chronicity in terms of long treatment trajectories and delayed recovery. Finally, with the proviso of good results for GST, we will disseminate and implement GST in the standard of care for EDs. This project thereby has great potential to improve clinical and cost-effectiveness of treatment for chronic EDs.

Enrollment: 230 estimated patients

Sex: All

Ages: 16+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• 1. age > 16 years;
• 2. a DSM-5 diagnosis of anorexia nervosa, bulimia nervosa, or other specified ED (atypical anorexia nervosa or bulimia nervosa with a low frequency or limited duration).

Exclusion criteria

• 1. not being able to speak and read the Dutch language;
• 2. being in an acute psychotic mental health state at the start of the study;
• 3. being diagnosed with an autism spectrum disorder;
• 4. having an IQ below 80, as determined with a validated instrument;
• 5. showing an early response after phase 1 of CBT-E.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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230 participants in 2 patient groups

Group Schema Therapy for eating disorders (GST)

Experimental group

Description:

GST starts with 5 individual sessions for introducing the ST model, placing the ED symptoms and behaviors in the context of coping modes, and organizing these in a mode map conceptualization. Thereafter there are 26 weekly group sessions of ST for EDs, supplemented with 8 optional individual ST sessions, and a psycho-education webinar for relatives. The sessions focus on recognizing and changing personal coping modes and underlying early maladaptive schemas, and developing and strengthening the healthy adult mode. GST combines interpersonal, experiential, cognitive and behavioral elements in a unified ST approach (Farrell et al., 2014). Although not at the core of GST, addressing the physiological aspects of the ED (weight care and (restrictive) eating) is necessary and therefore also incorporated in the protocol. Note that the participants in this condition have followed phase 1 and 2 of CBT-E before starting the GST, as following these phases is required to be included in the RCT.

Treatment:

Behavioral: GST

Cognitive Behavioral Therapy-Enhanced (CBT-E) (TAU)

Active Comparator group

Description:

This transdiagnostic ED treatment (current standard of care/treatment of choice) consists of 20-40 individual therapy sessions, based on the transdiagnostic CBT model of EDs. CBT-E consists of four phases. In phase one, the patient creates a personal case formulation, and the focus is on psycho-education on maintaining factors and at starting well with monitoring eating behaviours and establishing a regular eating pattern. In phase two, the first phase is evaluated and a treatment plan is made. In phase three, the main mechanisms that are thought to maintain the patient's ED (over-evaluation of shape, weight, and eating, dietary restraint or restriction, being underweight, and event- or mood-triggered changes in eating behaviour), are targeted, and a relapse plan is created. Phase four focuses on evaluating the progress so far and maintaining the changes that have been obtained (Fairburn et al., 2009).

Treatment:

Behavioral: CBT-E