Eating Disorder Outpatients Who Do Not Respond to Cognitive Behavioral Therapy: A Follow-Up Study
Authors: Giovanni Castellini, Luca Montanelli, Carlo Faravelli, Valdo Ricca
Journal: Psychotherapy and Psychosomatics (2014)

Cognitive behavioral therapy (CBT) is widely recommended for eating disorders (ED) by most evidence-based treatment guidelines [1]. However, less than a half of ED patients report a full recovery in the short term, and a consistent rate of patients only obtains partial remission of symptoms [2]. Patients who do not report any improvement have been described, but they often continue to receive care well beyond the standard time of empirically based treatment manuals [3]. Therefore, treatments provided may devolve into relatively unfocused, intermittent, supportive interventions [3], which finally result in being ineffective, expensive and time-consuming. Unfortunately, the scientific evidence for those ED individuals who do not respond to initial treatment, in terms of psychopathological description, is limited. An analysis of treatment moderators could allow us to identify patients with a lower likelihood of response to therapy, and thus to improve targeting for treatment. The study was conducted at the Outpatient Clinic for Eating Disorders of the Psychiatric Unit of the University of Florence, Italy. The details of the study design and procedure were already described elsewhere [4]. Outpatients referred to the clinic between June 1998 and February 2003 were enrolled in the study, provided they met the following inclusion criteria: age between 18 and 60 years; diagnosis of current DSM-IV anorexia nervosa (AN), bulimia nervosa (BN) or binge eating disorder (BED), assessed by means of the Structured Clinical Interview for DSM-IV [5]. Analyses were performed on a final sample consisting of 564 patients who participated in all 3 follow-ups [165 AN (46.1% restricting subtype), 137 BN and 262 BED patients]. The clinical assessment was conducted on the first day of admission, at the end of an individual CBT (T1), 3 years after the end of treatment (T2) and 3 years after the first follow-up (T3).CBT was provided over a minimum of 40 weeks for AN, 20 weeks for BN, and 24 weeks for BED [4]. Sociodemographic and clinical data were collected through a face-to-face interview and a clinical visit. Moreover, several self-reported questionnaires were administered, including the Eating Disorder Examination-Questionnaire (EDE-Q) [6], the Emotional Eating Scale (EES) [7], the Symptom Checklist 90-R, the Beck Depression Inventory and the State-Trait Anxiety Inventory. Patients were defined as 'CBT nonresponders' when no significant clinical improvement was observed at all 3 assessments after the baseline in terms of the DSM-IV diagnostic criteria. In particular, for AN when the body weight never reached the normal range, and for BN and BED when no significant change in any abnormal eating attitude and behavior was observed. Patients were considered 'recovered' when they did not fulfill the DSM-IV criteria for any ED (including ED not otherwise specified) for at least 8 weeks. Diagnostic crossover was considered when the assessment performed at one time point showed a different ED diagnosis than the diagnosis at baseline. The Mann-Whitney U test and the χ2 test were adopted to compare nonresponders with other patients within all diagnostic groups (AN, BN and BED). Potential outcome predictors were derived from the literature, and they included sociodemographic variables as well as eating-specific and general psychopathology. Moreover, we considered intermediate outcomes (crossover, weight recovery) as potential predictors of long-term nonresponse. All the potential predictors which were found to be associated with nonresponse in the univariate analyses were introduced into stepwise logistic regression analyses. Finally, linear mixed models (ANOVA mixed model with random intercept) were adopted to study the variation in clinical variables from baseline to 6-year follow-up (time effect; including T0, T1, T2 and T3 as time points) within each nonresponder group. EDE-Q scores and other psychopathological variables were the dependent variables for each model, and time was entered as the independent variable. The dropout/withdrawal rate was 11.5% for AN, 13.9% for BN and 11.8% for BED. The lost-to-follow-up rate was 6.1% for AN, 10.2% for BN and 8.0% for BED. The overall recovery rate at the 6-year follow-up was 52.1% for AN, 49.6% for BN and 59.2% for BED. The BN patients showed highest nonresponse rate (39 patients; 28.5%), followed by the AN patients (33; 20.0%) and the BED patients (37; 14.1%). Odds ratios (OR) and 95% CI (age- and gender-adjusted) for the nonresponse predictors are reported in figure 1. AN and BN nonresponders showed higher ED psychopathology (EDE-Q scores) than other patients. AN subjects with a duration of illness longer than 2 years (94 patients, 57%) showed a greater likelihood of becoming nonresponders, while within the BED group, nonresponders showed higher EES and Beck Depression Inventory scores, higher rates of unipolar depression comorbidity, and a duration of illness longer than 7 years (20.9 vs. 10.8%; χ2 = 4.8; p = 0.027). Substance abuse was associated with nonresponse in BN and BED patients. Considering events intervening during the follow-up period, AN patients who had not gained weight 1 year after the baseline (61 subjects, 37.0%) showed a higher probability of becoming nonresponders (46.6 vs. 9.4%, within not-fully-remitted patients; χ2 = 21.3; p < 0.01), while this particular association was not observed for further follow-ups. Nonresponse was associated with crossover in both BN and BED patients. According to the linear mixed models, nonresponders showed a significant reduction in restraint (AN and BN patients), eating concern (BN and BED patients), binge eating and purging frequency (for all groups), while no significant reduction was observed for weight and shape concern as well as for emotional eating (EES) in all groups.According to previous follow-up studies [2], we found that a consistent rate of patients did not respond to standard CBT and represented a subpopulation of ED subjects with specific clinical profiles. Psychiatric comorbidity was associated with both nonresponse and crossover. Diagnostic instability in turn was found to represent a risk factor for nonresponse in both BN and BED patients, possibly because it hides different psychopathological substrates on which standard CBT is relatively ineffective. In particular, BED nonresponders showed greater dysfunctional mood modulatory mechanisms (greater depression and emotional eating). This finding challenged the target of standard CBT: according to recent new CBT protocols (e.g. CBT-enhanced [8]), going beyond symptoms at the cognitive/behavioral level - and expanding the therapeutic focus to the underlying, implicit emotional meanings - would improve the effectiveness of CBT approaches.Moreover, our findings provide new evidence regarding the timing of CBT intervention and confirm that most of the relevant modifications to ED psychopathology usually occur within the first 5 years of illness [9]. Indeed, duration of illness and lack of weight restoration were risk factors for long-term nonresponse to CBT. Overall, these findings confirm that, after a period of time, the effects of the disorder significantly reduce the likelihood of a change in symptoms and highlight the importance of early intervention, reducing the time period in which the disorder is untreated and allowing patients to gain weight rapidly.Even if the results of the present study cannot be generalized to the general population or to inpatients, they challenge the definition of recovery/chronicity based on DSM criteria. At a purely behavioral level, CBT was capable of reducing restraint and binge eating/purging behaviors in most of the patients, even if nonresponders maintained their ED symptoms at a clinical level and their psychopathology did not show any significant long-term change. Therefore, disturbed eating behaviors appeared to be much more accessible to psychotherapy than the core attitudes about the ideal body. Indeed, nonresponders achieved a reduction in their ED symptoms, but they were unable to change their beliefs about the body. In order to treat patients not responding to CBT, targeting the therapeutic intervention at specific areas such as emotion dysregulation and/or body image distortion could be an alternative approach to avoid expensive, time-consuming and ineffective long-term interventions.