Declan received his Medical degree from Glasgow University in 1975 and joined Pfizer in 1982, where he was in charge of the sertraline® (Zoloft) clinical development programme. He has held a number of senior positions in research and development in Pfizer in the United States, United Kingdom, and Japan. He retired from Pfizer in 2007 as the Head of Worldwide Development. Declan has since held the positions of Interim CEO and Chief Medical Officer of Amarin Corporation. He is Executive Chairman of Biohaven Pharmaceuticals, CEO of Portage Biotech and co-founder and managing partner of Topix. Declan is on the Board of the not-for-profit Pulmonary Vascular Research Institute. He has held Visiting Professorships at Harvard School of Public Health, Glasgow University Medical School, and Kitasato University (Tokyo) and is Adjunct Professor of Psychiatry at the University of Cork. He is a Fellow of the Royal College of Physicians and the Faculty of Pharmaceutical Medicine in the United Kingdom and received a Doctorate of Science from the University of Kent, UK.