Major depressive disorder is the most common mood disorder in the United States today and the need for adequate treatment has been universally desired for over a century. Harry Harlow, famous for his research with rhesus monkeys, was heavily criticized when he undertook his controversial experiments trying to find a solution for depression in the 1960s–1970s. His research, however, did not just evolve gradually from his earlier research into learning and into love. Recently disclosed hand-written notes show, for the first time, the severity of Harlow's depressions as he wrote in detail about his feelings and thoughts during his stay in a mental hospital in 1968. In these notes, Harlow repeatedly vowed to put every effort into finding a cure for depression. This may, for a large part, explain why he did not stop his rigorous animal experiments where critics argue he should have, and he eventually managed to book positive results.
Bibliographical noteFunding Information:
This study was made possible by grants awarded to the first and third author by the Köhler‐Stiftung (no. S112/10210/16) and the Dr. J. L. Dobberke Stichting voor Vergelijkende Psychologie (no. 3819).
© 2022 The Authors. Journal of The History of the Behavioral Sciences published by Wiley Periodicals LLC.