A 15-year-old female is brought to an outpatient psychiatric clinic by her mother after the school counselor discovered superficial cutting marks on both forearms. The patient reports cutting herself with a razor blade approximately three times per week for the past two months to relieve intense emotional distress, particularly after interpersonal conflicts with peers. She denies suicidal intent and states she cuts to feel something or to release overwhelming feelings. She meets criteria for major depressive disorder with a PHQ-A score of 14 and demonstrates emotional dysregulation, chronic feelings of emptiness, and intense fear of abandonment. She has no prior psychiatric treatment. The PMHNP is developing a comprehensive treatment plan. Which of the following is the most appropriate approach?