I agree this "hyperfixation/hyperfocus" can occur in various mental health conditions. I've brought up this topic in the past, myself, and the usual automatic response of others is to say "Do you think you have ADHD?" The answer is no. I do not come close to meeting the criteria for that disorder. Hyperfocus, alone, is not sufficient.

I will say that I've experienced hyperfixation/hyperfocus predominately during elevated mood episodes, and that also includes mixed states. In fact, sometimes even more so during mixed states. A huge difference between my hyperfixation/hyperfocus and perhaps that of some with ADHD is that I often achieve my goals (often big ones) during such periods. However, if I aim WAAAAAAY too high, I might crash and burn, as a result. Of course sometimes I go from one to another thing, rapidly, but I then tend to be able to multi-task well. Definitely not the case during depressions, and often not the case when high anxiety is involved. But high excitement (of a better sort) is a different story.

There is something to the grandiosity of elevated states. Since they tend to be accompanied by superhuman efforts, faster "outside the box" thinking, it can be true that ideas flow easier. We can be a bit more creative and "intelligent" during those times. Just as depression can bring the opposite. Poverty of thought.

My moods have been quite level this year. I haven't felt particularly inspired or excited by anything. In fact, I'm at a loss for where to go next. I sort of wish I had a little more inspiration and zeal.