In Japan, however, I found myself suffering from Post America Depression or PAD. The environment for researchers in Japan was quite different in many ways from that in the U.S. At the medical school, very few scientists showed interest in the basic biology of mouse ES cells, and there was little thought-provoking discussion with my colleagues. Some of my colleagues advised me to work on something more related to medicine. Furthermore, I could not get enough funding and had to change the cages of the numerous mice by myself every week. What was worse, the Nat1 work was being rejected by many journals. I felt lonely and depressed, and I was about to give up my career as a scientist and return to the path of physician.
Recorded Laureate-written autobiography for Les Prix Nobel, Nobel Prize Outreach, 1 December 2012 source