Dr Breen completed her Masters of Science degree in Clinical Neuropsychology at the University of Melbourne in 1994 and then a PhD at Macquarie University in 2001. She began working as a Clinical Neuropsychologist in the Neuropsychology Unit at Royal Prince Alfred Hospital, Sydney, in 1995 and continue to hold a part-time position there. She has lectured for many years at the postgraduate level for The University of Sydney and the Brain & Mind Research Institute and is an Honorary Associate at Macquarie University. She is both a clinical and academic supervisor for postgraduate students in neuropsychology from The University of Sydney and Macquarie University. She is a full member of the Australian Psychological Society (APS) and the College of Clinical Neuropsychologists (CCN) and a Registered Psychologist with the Psychology Board of Australia (endorsed area of practice: Clinical Neuropsychology). Dr Breen joined Macquarie Neurology in 2011 and provide neuropsychology assessments for patients with a wide variety of neurological and neurosurgical disorders.