The impact of personality disorders and personality traits on psychotherapy treatment outcome of eating disorders: A systematic review

Clinical effectiveness, cost-effectiveness and process evaluation of group schema therapy for eating disorders: study protocol for a multicenter randomized controlled trial

BACKGROUND

Eating disorders (EDs), such as (atypical) Anorexia (AN) and Bulimia Nervosa (BN), are difficult to treat, causing socioeconomic impediments. Although enhanced cognitive behavioral therapy (CBT-E) is widely considered clinically effective, it may not be the most beneficial treatment for (atypical) AN and BN patients who do not show a rapid response after the first 4 weeks (8 sessions) of a CBT-E treatment. Alternatively, group schema therapy (GST) may be a valuable treatment for this ED population. Even though GST for EDs has yielded promising preliminary findings, the current body of evidence requires expansion. On top of that, data on cost-effectiveness is lacking. In light of these gaps, we aim to describe a protocol to examine whether GST is more (1) clinically effective and (2) cost-effective than CBT-E for (atypical) AN and BN patients, who do not show a rapid response after the first 4 weeks of treatment. Additionally, we will conduct (3) process evaluations for both treatments.

METHODS

Using a multicenter RCT design, 232 Dutch (atypical) AN and BN patients with a CBT-E referral will be recruited from five treatment centers. Clinical effectiveness and cost-effectiveness will be measured before treatment, directly after treatment, at 6 and at 12 months follow-up. In order to rate process evaluation, patient experiences and the degree to which treatments are implemented according to protocol will be measured. In order to assess the quality of life and the achievement of personalized goals, interviews will be conducted at the end of treatment. Data will be analyzed, using a regression-based approach to mixed modelling, multivariate sensitivity analyses and coding trees for qualitative data. We hypothesize GST to be superior to CBT-E in terms of clinical effectiveness and cost-effectiveness for patients who do not show a rapid response to the first 4 weeks of a CBT-E treatment.

DISCUSSION

To our knowledge, this is the first study protocol describing a multicenter RCT to explore the three aforementioned objectives. Related risks in performing the study protocol have been outlined. The expected findings may serve as a guide for healthcare stakeholders to optimize ED care trajectories.

TRIAL REGISTRATION

clinicaltrials.gov (NCT05812950).

Metacognitive interpersonal therapy-eating disorders versus cognitive behavioral therapy for eating disorders for non-underweight adults with eating disorders: study protocol for a pilot pre-registered randomized controlled trial

Eating disorders (ED) are serious disorders characterized by an alteration of eating habits and excessive concern about weight and body shapes (Fairburn, 2002), accompanied by significant impairment inequality of life, high mortality rates and serious organic consequences (Jenkins et al., 2011; Treasure et al., 2015; 2020). Although evidence-based psychological therapies for nonunderweight ED presentations such as cognitive behavioral therapy for eating disorders (CBT-ED) are widely available, there is substantial scope for improvements, particularly in terms of efficacy and adherence. One option is to develop interventions to address elements of pathology not fully addressed by existing empirical supported treatments, such as incorporating techniques aimed at addressing interpersonal problems and personality disorder features into existing treatment delivery. We adapted Metacognitive Interpersonal Therapy, a psychological intervention supported by evidence for treating personality disorders and integrated it with existing CBT techniques for eating disorders (MIT-ED). MIT-ED targets aspects of ED that are not included in the transdiagnostic CBT-E model such as poor metacognition, or maladaptive interpersonal schemas. This is a pre-registered (Protocol number: 0000781) pilot randomized clinical trial aimed at assessing acceptability and feasibility of MIT-ED and establishing preliminary evidence of effectiveness for future larger studies. Twenty patients (10 in each arm) will be randomized to 20 sessions of individual psychotherapy, either MIT-ED or CBTE. Repeated follow-ups will be collected up to 24 months. Participants are recruited at a private outpatient clinic for ED treatment. Acceptability will be assessed via session attendance, completion rates and preliminary outcomes. The primary outcome is ED pathology assessed with the Eating Disorder Examination Questionnaire-6. Other ED outcomes assessed will be eating disorder attitudes, clinical impairment and binge eating pathology. Secondary treatment outcomes are anxiety, depression, and global symptomatology. We will also assess emotional awareness, emotion regulation and therapeutic alliance. Based on previous studies of MIT for personality disorders we hypothesize that MIT-ED will be acceptable to patients, evidenced by high treatment adherence and retention. We hypothesize that MIT-ED will be associated with reductions in eating disorder pathology, at least equivalent to CBT-E. Results will be used to inform the study design, sampling, likely effect sizes and choice of outcome measures for future larger trials of MIT-ED in ED samples.

Reciprocal relationships between personality disorders and eating disorders in a prospective 17-year follow-up study

OBJECTIVE

This study aimed to report the presence of categorical and dimensional personality disorders (PD) in adults with longstanding eating disorders (ED) over a period of 17 years and to investigate whether changes in PD predict changes in ED symptoms or vice versa.

METHODS

In total, 62 of the 80 living patients (78% response rate) with anorexia nervosa (n = 23), bulimia nervosa (n = 25), or other specified feeding or ED (n = 14) at baseline were evaluated during hospital treatment and at 1-year, 2-year, 5-year, and 17-year follow-up. PD were assessed using the Structured Clinical Interview for DSM-IV Axis II disorders, and the eating disorder examination (EDE) interview was used to assess ED. Data were analyzed using multilevel modeling.

RESULTS

From baseline to the 17-year follow-up, the number of patients with any PD decreased significantly from 74.2% to 24.2%, and the total number of PD diagnoses declined from 80 to 22. Mean EDE score was significantly reduced from 4.2 (SD: 1.1) to 2.0 (SD: 1.6). There was a positive association between ED and PD where the initial level of either disorder was followed by similar levels of the other disorder throughout the entire follow-up period. High baseline levels of borderline PD predicted less decrease in ED symptoms. No significant within-person effects were found.

CONCLUSIONS

Both ED and PD significantly declined over time. As the severity of either disorder seems to be associated with the other, thorough assessment and treatment that incorporates both the ED psychopathology and the personality disturbances are advisable.

PUBLIC SIGNIFICANCE STATEMENT

While personality disorders were highly prevalent in the sample of patients with longstanding eating disorders, both disorders were significantly reduced at the 17-year follow-up. The disorders are related in the sense that an initial high level of either disorder is associated with a high level of the other over time. A thorough assessment and attention to both illnesses are advisable in therapy.

CLINICAL TRIAL IDENTIFIER

NCT03968705.

An exploratory study of associations between the ICD-11 personality disorder model and eating pathology

BACKGROUND

Recently, the International Classification of Diseases 11th Revision (ICD-11) has introduced a paradigm shift in personality disorder conceptualization. The novel ICD-11 personality disorder model comprises a dimensional assessment of personality dysfunction and five maladaptive personality trait domains. Maladaptive personality plays a central role in eating pathology. Yet, relations between the ICD-11 personality disorder model and eating pathology are, to date, unclear. Thus, this study aimed to explore the bivariate, incremental, and interactive associations of the ICD-11 personality disorder model components with eating pathology domains.

METHODS

A predominantly female (85%) sample of 888 German-speaking community adults completed validated self-report measures of personality dysfunction, the ICD-11 personality trait domains, and five eating pathology domains (drive for thinness, bulimia, body dissatisfaction, orthorexia, binge eating). Bivariate and hierarchical regressions models were used to investigate bivariate, incremental, and interactive relations between the ICD-11 personality disorder model components and eating pathology.

RESULTS

Personality dysfunction and the ICD-11 personality trait domains showed statistically significant bivariate relations with eating pathology. Additionally, personality dysfunction and most ICD-11 personality trait domains displayed incremental links with eating pathology. Finally, the relations of the ICD-11 personality trait domains with eating pathology were largely independent of the severity of personality dysfunction.

CONCLUSIONS

This study indicated that all ICD-11 personality disorder model components are uniquely linked to eating pathology. Beyond maladaptive personality trait domains, the strong and incremental relations of personality dysfunction with eating pathology have potential implications for theory building. Further research using longitudinal designs is needed to evaluate causal links between the ICD-11 personality disorder model components and eating pathology.