The assessment and diagnosis of atypical anorexia nervosa (AAN) is an ongoing challenge for clinicians. This study aims to examine psychological morbidity and exposure to childhood adversity in adolescents with AAN compared to adolescents with anorexia nervosa, restricting type (AN-R). This registry-based study compared 42 adolescents with AAN to 79 adolescents with AN-R on a variety of psychosocial measures at the time of presentation to a specialized eating disorder program. In contrast to AN-R, adolescents with AAN had more severe drive for thinness (p =.011), body dissatisfaction (p =.038), and lower quality of life (p =.047), but had better global functioning (p =.032). Adolescents who had high Adverse Childhood Experiences (ACE) Questionnaire scores (ACE score ≥ 4) had over 5 times higher odds of having AAN than those who did not have high ACE scores (p =.008). There was no significant difference between groups on measures of low self-esteem and non-accidental self-injury. Adolescents with AAN presented with similar or more severe psychosocial distress compared to their peers with AN-R across a majority of the measures. The findings highlight the need to address trauma, body-related difficulties, and quality of life in the assessment and treatment of adolescents with AAN.