In this case study we present the course of the psychotherapy of Myriam, a 19‐year old female with a severe personality disorder and comorbid eating disorder. During the initial assessment she reported high levels of neuroticism that parallel the diagnosis of obsessive‐compulsive personality disorder, borderline personality disorder, and anorexia nervosa. Myriam showed a severely impaired personality functioning defined by perfectionism, self‐criticism, interpersonal guilt and overcontrol. Her daily experience was shaped by a self‐recriminative inner dialogue associated with maladaptive patterns in the form of food, water and sleep restrictions, self‐harm behaviors, and suicidal ideation. She accessed an integrative treatment based on individual (Evolutionary Systems Therapy) and group psychotherapy (Mindful Compassion for Perfectionism). At the end of 14‐month intervention she remitted from all the categorical diagnoses and showed reliable changes in several measures. These outcomes were maintained at 3‐month follow‐up. We describe the integrative conceptualization based on Myriam's perfectionistic self‐recrimination patterns, and the consequent treatment that targeted these patterns rather than focusing on symptom reduction exclusively.