As a graduate of University of Heidelberg Medical School, Dr. Sonntag studied the molecular biology of viruses, and as a research fellow at the Transplantation Biology Research Center at Massachusetts General Hospital, he conducted research in transplantation immunology. In 2000, he joined McLean Hospital where his laboratory is integrated in the Program for Neuropsychiatric Research, directed by Dr. Bruce Cohen.

Amongst others, Dr. Sonntag’s work has contributed to developing a cell therapy for Parkinson’s disease (PD), and to understanding a role of dysregulated gene and miRNA expression networks in PD and schizophrenia, or dopaminergic and adrenergic receptors in hedonic and impulsive behavior. His research has also discovered a novel mechanism to regulate neurotrophic growth factor-associated signaling pathways by miRNAs in context of PD and Alzheimer’s disease (AD), and a role of dysfunctional bioenergetics in the pathogenesis of late-onset AD.