I'm a little confused about the author's form of depression. He seemed to be able to still experience positive emotions and feelings. I don't mean to dismiss or invalidate his experience but I think depressive periods brought on by a real factor in life, say a personal hardship or stressor (in his case it seemed like work) are very, very different than chronic treatment resistant depression with anhedonia.

One of the hardest symptoms of depression to treat is anhedonia, meaning blunted or no responses to positive emotions. Having severe anhedonia is both difficult to treat pharmacologically and therapeutically.

I'm in the same boat as this author with habits/productivity, but with severe anhedonia, that only gets you so far. You can't use cheat codes, you only really know what to avoid. Since you don't really respond to rewards or dopamine hits everything is kind of messed up. You can maintain a momentum and it's better than sinking into oblivion but it always just kind of feels like treading water because the alternative is worse. I have to force myself to do everything, even things I "like" doing and it's very exhausting.

So anyway glad that this author found a way out of his situation but just as an alternative viewpoint this form of depression is more common and has a better prognosis. Some people have other forms of depression for which this approach is lacking something because if you don't naturally feel positive emotions regardless of what's going on (and regardless of treatment modality, hence treatment resistant) stuff gets pretty messed up. You can change your actions and habits but not how you feel and if you're always trying to compensate by not having an innate positive feeling or drive about something you can get a momentum but then you're stuck there. It's better than the alternative and you make peace with it but it will always be kind of a broken system.