A variety of psychotherapy techniques work well for eating disorders, particularly for bulimia nervosa and binge eating disorder. Below is a brief summary of the evidence from controlled clinical trials.
Cognitive Behavioral Therapy (CBT).
The Technique. The theory behind CBT for bulimia nervosa (BN) is that these patients have developed distorted cognitions about both their weight and body image. Because they over-value thinness, they restrict their food intake in a rigid and unrealistic manner. This food restriction causes hunger, which leads to bingeing, which in turn triggers lowered self esteem, guilt and anxieties about gaining weight. The patient then purges, self-starves, or exercises compulsively to compensate for the binge, leading into the binge-purge cycle. CBT treatment consists of encouraging a regular pattern of eating that includes previously avoided foods, teaching more constructive skills for coping with high risk emotional situations, and modifying distorted perceptions of food and eating. (For some interesting clinical examples of the technique, see this month’s interview with Joel Yager, MD).
The Research. CBT for BN has been shown to be superior to both waiting list control groups and medication alone in several trials (Shapiro et al, Int J of Eating Disorders, 2007 40:4 321-336). One large trial randomly assigned 220 bulimic patients to either CBT or interpersonal psychotherapy (IPT). After 20 weeks, patients receiving CBT did significantly better than IPT patents, both in terms of the percentage of patients recovered (29% vs. 6%), and the percentage remitted (48% vs. 28%). (“Recovered” meant no binge eating or purging during the previous 28 days and “remitted” was defined as binge eating and purging less than twice per week over the previous 28 days.) However, at one year follow-up there were no significant differences between the two treatments (Agras, et al., Arch Gen Psychiatry, 2000; 57:459-466). In most studies of CBT, the technique works quickly over the first months of treatment, and there is evidence that early progress in CBT best predicts long term outcome (Agras, et al., Am J Psychiatry, 2000; 157:1302-8). Unfortunately, neither CBT nor IPT have been shown to be effective for treating anorexia nervosa (AN). In fact, one randomized controlled trial of 56 women with AN found that, after 20 weeks, nonspecific supportive psychotherapy was actually superior to both CBT and IPT, implying that manual-driven psychotherapies may alienate these patients (McIntosh, Am J Psychiatry, 2005;162:741-7).
Interpersonal Psychotherapy (IPT)
The Technique. IPT focuses on ways that problematic relationships cause psychiatric symptoms. After evaluating how the eating problem first developed, the therapist works with the patient to understand the context of the eating disorder symptoms in interpersonal problem areas such as role transitions, grief, role disputes, or interpersonal deficits. The therapist avoids detailed discussions of the disordered eating symptoms and instead encourages the patient to explore the interpersonal context in which the symptoms occur (Apple, Psychotherapy in Practice, 1999; 55, 715-725).
The Research. IPT has shown benefits for patients with BN (see study comparing it with CBT above) and there is evidence that it is effective for patients with Binge Eating Disorder (BED) as well. One RCT (Wilfey, Arch Gen Psychiatry, 2002; 59: 713-21) randomly assigned 162 overweight patients with BED to 20 weekly sessions of either group CBT or group IPT. Binge-eating recovery rates were equivalent for both groups after completion of the 20 week therapy (CBT, 64 of 81, 79%; IPT, 59 of 81, 73%) and at one year followup (CBT, 48 of 81, 59%; IPT, 50 of 81, 62%).
The Technique. Both DBT (Dialectical Behavioral Therapy) and ACT (Acceptance and Commitment Therapy) view disordered eating as being motivated by a need to escape painful emotional states. Therapy encourages patients to develop what is termed “noncritical awareness” of intense negative emotions. By accepting their emotions without acting on them, and using CBT techniques to modify their behavior, patients ultimately increase their ability to curb their impulsivity and thereby develop self esteem.
The Research. One RCT compared 20 weeks of DBT versus waiting list control in 44 women with DSM-IV BED. At the end of treatment, 89% of the participants in DBT had stopped binge eating, compared to 12.5% of the wait list group. At six month follow up, 56% of the DBT participants continued to be abstinent from binge eating (Telch, J Consult Clin Psychol, 2001; 69: 1061-5). Another 20-week RCT that compared 31 women who received DBT with a waiting list control condition found significant treatment effects for the frequency of both binge eating and purging behaviors (Safer, Am J Psychiatry, 2001; 158:632-4).
Family Based Psychotherapy (FBT)
The Technique. As we covered in the October 2007 issue of TCPR, FBT is a type of family therapy in which parents are initially encouraged to become re-involved in their child’s care to and take full control of food decisions. Once the patient achieves a normal weight, the second part of the therapy slowly gives control over food back to the patient with a focus on the effects the eating disorder has had on the child’s school and social life.
The Research. FBT has shown efficacy for adolescents with both BN (Le Grange et al., Arch Gen Psychiatry, 2007; 64:1049-1056) and AN (Paulson-Karlsson et al., Eat Disord, 2009 ; 17:72-88). For further details, please see TCPR October 2007.
TCPR VERDICT: Psychotherapy for Eating Disorders is effective. It may turn out that some types work better than others over the long term, or with particular types of patients, but we don’t yet have the answers.