Prominent autistic traits and subthreshold bipolar/mixed features of depression in severe anorexia nervosa

Autistic traits are associated with a burdensome clinical presentation of anorexia nervosa (AN), as is AN with concurrent depression. The aim of the present study was to explore the intertwined association between complex psychopathology combining autistic traits, subthreshold bipolarity, and mixed depression among people with AN.

Sixty patients with AN and concurrent major depressive episode (mean age, 22.2±7 years) were cross-sectionally assessed using the Autism-Spectrum Quotient test (AQ-test), the Hamilton depression scales for depression and anxiety, the Young Mania Rating Scale (YMRS), the Hypomania-Checklist-32 (HCL-32), second revision (for subthreshold bipolarity), the Brown Assessment and Beliefs Scale (BABS), the Yale-Brown-Cornell Eating Disorders Scale (YBC-EDS), and the Eating Disorder Examination Questionnaire (EDE-Q). Cases were split into two groups depending on body mass index (BMI): severe AN (AN+) if BMI < 16, not severe (AN-) if BMI ≥ 16.

The "subthreshold bipolarity with prominent autistic traits" pattern correctly classified 83.6% of AN patients (AN+ = 78.1%; AN- = 91.3%, Exp(B) = 1.391). AN+ cases showed higher rates of positive scores for YMRS items 2 (increased motor activity-energy) and 5 (irritability) compared to AN- cases.

In our sample, depressed patients with severe AN had more pronounced autistic traits and subtly mixed bipolarity. Further studies with larger samples and prospective follow-up of treatment outcomes are warranted to replicate these findings.