With you on this. There is no diagnostic test for glucose/dopamine depletion, and it is unlikely theory in my opinion. Even when you haven't eaten the circulatory system keeps the brain flushed with glucose from the liver or muscle glycogen, and then ketone bodies from ketogenesis. Unless you have a constant flow of these nutrients supported by a normal blood pressure, you pass out quickly. I don't think it's a surprise that he started to improve when he started antidepressants, started seeing a therapist (the psychologist), started exercising more, and took a less stressful job. To me it sounds like anxiety that built up repeatedly after 30 minutes of working. He states that he felt a numb nothingness (anhedonia), had trouble concentrating, and had psychomotor slowing. Only needs one more to hit the criteria for major depressive disorder, and I'm guessing he was having trouble sleeping at this time. From what he wrote ("It was a physical issue.") it looks like he was going to search until he found a non-psychiatric diagnosis, seeking out a neuro-psychologist (someone with likely no biochem/physiology background), to propose a theory about something that is unlikely.

Regarding the post up above about a TIA (thank you for sharing this story) or the one below about the Microsoft engineer who had neck pain and then a stroke (carotid or vertebral artery dissection, often caused in younger people by car crashes or neck manipulation by a chiropractor..), I think a TIA/stroke is much less likely in this guy's case because of the recurrence of the symptoms after being able to work for a period of time. Someone who's had a TIA hitting Broca's area (motor speech) won't be able to work for a little and then have to stop, they're just not going to be able to speak/type. And unless they're very unlucky they're not going to have them repeatedly only after working for a short period of time. Maybe it is an exact match with the TIA post above with anxiety/PTSD after the initial TIA with word finding difficulty, but it doesn't seem like this guy had word finding difficulty at first because he was able to work after sleeping off his stroke.

If you want to run with glucose, he could have type I diabetes or an insulinoma if you want to go rare, but the symptoms are going to be resolved immediately after eating anything with carbs.

But what do I know, just a student in the American medical system.