Dr. Seibyl received his undergraduate degree at Yale University and completed his medical degree at Case Western Reserve University in Cleveland, Ohio. Dr. Seibyl trained as a post-doctoral fellow in the Department of Psychiatry at Yale University and joined the faculty upon completion of this training. While on the psychiatry faculty, Dr. Seibyl's interest in brain imaging led to his returning for a training fellowship in nuclear medicine.  Dr. Seibyl subsequently became Chief of the Section of Nuclear Medicine and Director of the Yale-VA PET Center; he is currently executive director and senior scientist at the Institute for Neurodegenerative Disorders.

Dr. Seibyl has won numerous grants and contracts in the context of his work in brain imaging. Recent projects include the development of a web-based normal brain image database and on-going work applying brain imaging techniques to improve the diagnosis and assessment of disease status in patients with neurodegenerative diseases. He is board-certified in both psychiatry and nuclear medicine.