Edo Ronald de Kloet: How does the action of glucocorticoids change from protective to harmful? What is the cause? And what are the consequences?

For half a century, Edo Ronald (Ron) de Kloet has pursued a fundamental question in neuroscience: how do stress hormones switch from protecting our brain to potentially harming it? After receiving his PhD in 1972 at the University of Utrecht under David de Wied's mentorship, he spent two formative years with Bruce McEwen at Rockefeller University before returning to the Rudolf Magnus Institute. In 1990, he was appointed Professor of Medical Pharmacology at Leiden University, where he discovered how a single hormone – cortisol – could protect and damage the brain through two distinct receptor systems (MR and GR). This finding opened new paths for understanding and treating stress-related mental disorders. His research, spanning over 600 publications, has transformed our grasp of how the brain copes with stress and earned him numerous honours, including the Geoffrey Harris Award (2005), the ECNP Award (2007), and the Golden Emil Kraepelin Medal (2014) for advancing our understanding of depression. Though officially “retired” since 2009, he remains active as an emeritus professor at Leiden University Medical Centre and academy professor at the Royal Netherlands Academy of Arts and Sciences. Recognizing his contributions to science and society, he was knighted in the Order of the Dutch Lion in 2010. Recently, alongside his long-time collaborator Professor Marian Joëls, he received the 2024 Global Stress & Resilience Network Pioneer Award. In this Genomic Press Interview, Dr. de Kloet reflects on his remarkable journey and shares fresh insights into the fascinating world of stress neuroscience.