The impact of DSM‐5 on the diagnosis and severity indicator of eating disorders in a treatment‐seeking sample

Objective To examine the impact of the DSM‐5 on the diagnoses and severity indicators of eating disorders, we conducted a comparative study on the classification of eating disorders including subtypes of anorexia nervosa (AN) between the DSM‐IV and DSM‐5 criteria. In addition, we studied the association of the DSM‐5 severity criteria and clinical variables. Method Participants were 304 outpatients, aged 16–45 years, with eating disorders, diagnosed using semi‐structured clinical interviews and the eating disorder examination questionnaire (EDE‐Q). The severity of AN, bulimia nervosa (BN), and binge‐eating disorder (BED) was rated from mild to extreme using the DSM‐5 severity criteria. Results The DSM‐5 remarkably reduced the number of diagnoses in the residual category from 37.5% to 9.2% and effectively differentiated the diagnostic groups in eating disorder psychopathology. Unexpectedly, however, the scores of all the EDE‐Q subscales significantly decreased as severity ratings increased in the DSM‐5 AN. Furthermore, while the AN binge‐eating/purging group reported significantly lower severity ratings than the AN restricting group, the former displayed more severe eating disorder psychopathology than the latter. In the BN and BED groups, the level of eating concern increased as severity ratings increased, but the severity groups did not differ on other eating pathology variables. Discussion The DSM‐5 effectively reduced the reliance on residual categories and differentiated the diagnostic groups in eating disorder psychopathology. However, our findings show limited support for the DSM‐5 severity specifiers for eating disorders. It is necessary to test additional clinical or functional variables for severity specifiers across eating disorders.