Cognitive Behavioral Therapy (CBT) is effective for less-recognized eating disorders
Most people are aware of the most common eating disorders – anorexia nervosa, bulimia nervosa, and binge eating disorder. However, not every person living with clinically significant disordered eating fit into these categories.
There is a wide variety of eating disorder subtypes, such as atypical anorexia nervosa, purging disorder, and subthreshold bulimia nervosa, and there has been little research into understanding or treating these subtypes.
Recently, a team of researchers from the University Hospital of Bellvitage-IDIBELL, in Barcelona, Spain, sought to see whether these diverse forms of lesser-known eating disorders would respond to the most widely used form of therapy for eating disorders, known as cognitive-behavioral therapy (CBT).
The findings, published in European Psychiatry, revealed that overall CBT is beneficial for almost all forms of eating disorders.
Due to lack of recognition and relatively small prevalence compared to disorders like anorexia and bulimia, research into atypical eating disorders has historically been rare and difficult. This has been complicated even more by changing definitions and classification within the wider medical community.
“The update of the DSM-5 reconfigured and renamed [eating disorder not otherwise specified] as other specified feeding or eating disorder,” Nadine Riesco, Ph.D., from the department of psychiatry at University Hospital explained. “However, because this [classification] is relatively recent, most of the research in this field refers to [eating disorder not otherwise specified], while [other specified feeding or eating disorder] subtypes have barely been studied in the literature so far.”
To test the effectivity of CBT on these eating disorder subtypes, the teams evaluated 176 female patients diagnosed with one of the lesser-recognized subtypes of eating disorders. Specifically, they assessed their short-term response to CBT, as well as eating-related, psychopathological and personality assessments.
Among the participants were 99 women with atypical anorexia nervosa, 57 with purging disorder, and 37 with subthreshold bulimia nervosa. All participants received the same 16-week outpatient group therapy utilizing CBT to teach problem-solving strategies, cognitive restructuring, emotion regulation, improving self-esteem and body image, and relapse prevention strategies.
Psychopathological and personality measures showed little difference among the subtypes. The only notable distinction was that those with subthreshold bulimia nervosa exhibited higher social impairment.
The researchers found that CBT was similarly effective across participants despite different eating disorder subtypes. By the end of the 16-week therapy course, 99 patients had remained in the study, with 72 achieving a positive outcome. Nearly half (46.5%) had achieved partial remission, while 26.3% reached full remission.
The dropout rate for each group was also relatively similar, with between 36.8% and 50% of each group dropping out over the course of treatment. However, the team did note that some personality traits may predict the chances of full remission or dropout.
“The high dropout rates open the debate and highlight the need to add other therapeutic tools for improving the therapeutic adherence of these patients, for example, family, motivational or insight-based treatments,” Riesco and colleagues wrote.
“Future research should assess and compare key maintenance factors, such as denial of illness, lack of awareness, anosognosia or impaired insight, as well as their association with therapy outcome,” they continued. “This will benefit clinicians to obtain a better conceptual understanding of the processes involved in the treatment of these patients.”