Brenda Penninx is a leading researcher worldwide on depression. Her large-scale, interdisciplinary approach to studying the causes, course and consequences of depressive disorders is unique. For example she was the principal investigator of the Netherlands Study of Depression and Anxiety (NESDA).
Her work is crucial for demonstrating and understanding the connection between depression and somatic disorders such as cardiovascular disease and diabetes. She has also shown that there are different types of depression, for example one displaying typically melancholic symptoms and another with atypical and immunometabolic traits, presumably requiring different personalised treatment strategies. This can be regarded as a major breakthrough in the study of depression.