Catharina Armstrong MD/MPH is Associate Director of the Newton-Wellesley Hospital Substance Use Services. Dr. Armstrong graduated from University College Dublin School of Medicine. She completed Internal Medicine residency training at Massachusetts General Hospital and a fellowship in Infectious Diseases at Beth Israel Deaconess Medical Center. Dr. Armstrong was awarded a Masters in Public Health from Harvard Medical School in 2015.

​She is board certified in Internal Medicine, Infectious Diseases and Addiction Medicine and is an Assistant Professor at Tufts University School of Medicine. Her clinical and research interests are in prevention and management strategies to support high risk groups with infectious diseases, particularly co-infection with Hepatitis B and C and HIV.