Online therapy can help treat bulimia, offering hope for women lacking access to care, reveals study

Bulimia nervosa (BN), or bulimia, is a mental health disorder characterized by binge eating and a fear of gaining weight, which drives people to try and avoid weight gain, usually by compensatory (vomiting etc.). Over time, this binge–purge cycle harms both physical and mental health of the individual, leading to problems like dehydration, low blood pressure, depression, and even self-harm. BN mostly affects young women and often begins in their teenage years, with studies showing that up to three percent of women may experience BN at some point in their lives, putting them at higher risk if left untreated.

BN is thought to develop from harmful learned habits that can be changed with cognitive behavioral therapy (CBT). This approach helps people break the binge–purge cycle by challenging negative thoughts and beliefs related to dieting and body weight. However, for many people, especially those living far away from specialist clinics, accessing face-to-face therapy is not always easy or even possible.

Now, in the first study of its kind conducted in Asia, an international team of researchers have shown that CBT can also be effective when delivered online. Their findings suggest that guided internet-based CBT (ICBT) can help people who otherwise struggle to get specialist care.

The study was conducted by Dr. Sayo Hamatani from the Research Center for Child Mental Development, University of Fukui, Japan, and included several co-authors, such as Dr. Kazuki Matsumoto from Kagoshima University, Japan; Dr. Gerhard Andersson from Linköping University in Sweden; and Dr. Yoshifumi Mizuno from the University of Fukui, along with researchers from Tohoku University Hospital, Chiba University, Dokkyo Medical University Saitama Medical Center, National Center of Neurology and Psychiatry, and Tokushima University. The results were published online in Volume 8 of the journal JAMA Network Open on August 05, 2025.

“We undertook this study to lower barriers to accessing specialist care and help create a society where people can receive high-quality treatment regardless of where they live. By establishing a specialist online therapy that can be delivered at home, even patients in remote areas or with busy schedules will find it easier to continue treatment, supporting early intervention and preventing progression to more severe forms,” explains Dr. Hamatani as she speaks of the motivation behind the study.

The researchers assessed the efficacy of guided ICBT by comparing it to that of usual care. To this end, they recruited 61 women between the age of 13–65 years (average age: 28 years), who were randomly assigned either to an intervention group that received guided ICBT or to a control group that continued with usual care. The program lasted 12 weeks, during which participants in the ICBT group worked through weekly online modules adapted for Japanese patients and received support from a therapist through an online platform. The program included strategies to help people resist urges to binge and purge, such as exercises to face triggers in a safe way and activities to help reshape negative views about their own bodies.

When the researchers compared the results at baseline and 12 weeks post-intervention, they found that women in the ICBT group showed significantly reduced binge eating and compensatory behaviors compared to those in the usual care group, with an average decrease of about 10 episodes in total. The percentage of women whose symptoms improved enough to be considered in remission, rose from just 13% with usual care to up to 55% with ICBT. Participants also reported feeling more satisfied with the online program, with more than 75% stating they would return to this treatment program if they needed help again.

These findings strongly make the case for continued support as essential for treating BN and preventing the condition from becoming more severe. Making CBT available online could very well be a game-changer for people who cannot easily access a clinic. “With insurance support and integration into healthcare systems, this approach could reach many more people and play a key role in treating BN,” highlights Dr. Hamatani.

Developing a system based on this study could potentially lead to high-quality care, promoting equitable mental healthcare and improving the overall quality-of-life among patients with BN.

Reference:

Hamatani S, Matsumoto K, Andersson G, et al. Guided Internet-Based Cognitive Behavior Therapy for Women With Bulimia Nervosa: A Randomized Clinical Trial. JAMA Netw Open. 2025;8(8):e2525165. doi:10.1001/jamanetworkopen.2025.25165