Menstrual characteristics of atypical anorexia nervosa.

Objective: While menstrual irregularities are acknowledged in restrictive-type eating disorders (EDs), the menstrual characteristics specific to atypical anorexia nervosa (AAN) remain inadequately defined. This study aims to compare the menstrual features of anorexia nervosa (AN) and AAN.

Method: Adolescents diagnosed with AN or AAN who exhibited secondary amenorrhoea at presentation and had their menstrual cycles restored during follow-up were eligible for this study. Clinical and menstrual data at admission and during follow-up were obtained from patient files, and compared between the AN and AAN cohorts.

Results: The study included a total of 77 patients (38 with AN and 39 with AAN). The extent of weight loss and the disease duration until the onset of amenorrhoea were comparable in the two groups. However, the duration of illness and the time since the last menstrual period at admission were shorter in the AAN group. Moreover, amenorrhoea manifested at a higher body mass index, and the return of menses occurred more rapidly with less weight gain in the AAN group after the onset of clinical follow-up. Additionally, the AAN group exhibited a shorter overall duration of amenorrhoea.

Conclusions: This study highlights the significance of recognising amenorrhoea in restrictive disorders, even when individuals maintain a normal weight. The faster return of menstrual cycles and shorter duration of amenorrhoea observed in adolescents with AAN emphasise the significance of early diagnosis and prompt initiation of treatment. Regardless of the patient's presenting complaint and weight status, obtaining a comprehensive ED history is essential when addressing concerns regarding amenorrhoea or menstrual irregularities.