The psychological integration of body-related attitudes (BodyRA) is a critical developmental task in adolescence. Adolescents must adapt to their changing body image and body satisfaction. For young people, BodyRA (body dissatisfaction, bulimia, and drive for thinness) are connected to insecurities, which can disturb identity integration and personality development. Our goal was to evaluate the importance of BodyRA also for other mental disorders other than anorexia nervosa (AN), and the association between BodyRA with temperament and personality traits and identity diffusion. Data for the period of 2012 to 2019 were retrospectively analyzed from a convenience sample of patients in a child and adolescent psychiatric hospital ( = 114). The patients were 13 to 17 years of age and had a BMI of 11.9-36.1 kg/m. As expected, BodyRA were found to be more pronounced in AN, as well as in borderline personality disorder (BPD), depression (DD), and attention deficit hyperactivity disorder (ADHD). BodyRA correlated significantly with internalizing problems in patients with DD ( = 0.428-0.565, < 0.01) and BPD ( = 0.680, < 0.01) as well as with BMI ( = 0.404, < 0.01) in patients with DD. Moreover, we detected significant correlations with impaired identity development in patients with DD ( = 0.482-0.565, < 0.01) and BPD ( = 0.681-0.703, < 0.01). BodyRA also correlated significantly with the personality traits of harm avoidance ( = 0.377-0.541, < 0.01) and self-directedness ( = -0.537--0.635, < 0.01) in DD. These personality traits and bulimia were used as predictors for identity diffusion in the investigated disorders of this study. We conclude that BodyRA, harm avoidance and self-directedness are associated with identity development in adolescent females with mental disorders.