Dr. Mackenzie Sommerhalder is a licensed psychologist and an assistant in the Johns Hopkins School of Medicine, Department of Psychiatry and Behavioral Sciences, Division of Child and Adolescent Psychiatry. She specializes in the assessment and treatment of children, adolescents, and their families requiring emergency, intermediate, and acute levels of psychiatric care. She specifically works closely within multidisciplinary treatment teams as the lead psychologist and behavioral consultant in the pediatric emergency department (PED), the Child and Adolescent Day Hospital, and the Bridge Clinic. Research and clinical interests broadly include: ED diversion, behavioral parent training in acute and intermediate care settings, improving measurement-based care in youth partial hospitalization programs, staff training in crisis intervention and prevention, improving hospital-to-school transitions, caring for neurodiverse youth with comorbid severe behavior in the PED, and foster care youth boarding.

Dr. Sommerhalder earned her B.A. in Psychology from Creighton University, her M.A. in School Psychology from University of Nebraska-Lincoln, and her Ph.D. in Educational Psychology from University of Nebraska-Lincoln. She completed her pre-doctoral internship at Kennedy Krieger Institute in the Behavior Management Clinic and the Pediatric Psychology Consultation Program, and her post-doctoral fellowship in the Pediatric Medical Psychology Program at Johns Hopkins Children’s Center. Prior to returning to Johns Hopkins, Dr. Sommerhalder was an assistant professor and served as the Director of Acute Pediatric Psychological Services at the University of Maryland School of Medicine Division of Child and Adolescent Psychiatry.