Onset patterns and clinical features of binge-eating disorder in a Japanese clinical sample.

OBJECTIVE: This study aimed to investigate the clinical presentation of binge-eating disorder (BED) in a Japanese sample and to examine the relationship between subtypes of BED differing in onset patterns and those differing in prior history of another eating disorder (ED). METHODS: The study participants were 137 adults who met the fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria for BED. We subtyped participants based on prior history of another ED: 55 (40.1%) participants with a history of another ED (BED ED+) and 82 participants without such a history (BED ED-). RESULTS: Unlike in some Western studies, approximately three quarters of participants had a body mass index of <25 kg/m2 . None of the participants reported a history of another ED with purging or excessive exercise. All BED ED+ participants transitioned to BED from anorexia nervosa restricting type (AN-R) or from atypical AN-R. BED ED+ participants reported more severe psychopathology than BED ED-participants. Only 20% had a treatment history for BED. Dieting preceded their first binge eating in 55 participants (DIET-first BED), and binge eating preceded their first dieting in 82 participants (BINGE-first BED). Regarding the relationship between the two different subtypes, all DIET-first BED participants were in the BED ED+ group, whereas all BINGE-first BED participants were in the BED ED-group. DISCUSSION: Present findings revealed the clinical presentation of BED in a Japan-based study and suggested that subtypes of BED differing in the prior history of another ED yielded an accurate prediction of onset patterns (dieting first vs. binge eating first). PUBLIC SIGNIFICANCE: This study highlights the need for clinicians to consider subtype differences in onset patterns and clinical features of BED to treat and prevent this disorder. This study revealed that, although individuals with BED in Japan have severe symptoms and a long duration of illness, only 20% have received BED treatment. The results indicate a need to disseminate knowledge about BED to the Japanese public and healthcare providers.