[wongarsu]

I think a lot of this is about English (and probably most languages) being vary lacking in ways to describe both short-time and long-time mood effects. Talking about a dopamine rush from completing a difficult task or an endorphin rush from sport isn't very accurate, but despite everyone knowing the feeling we never made better words for them.

Similarly "I've low dopamine" is just a modern version of "I have the blues" or "I'm depressed". That's all good, as long as everyone involved knows that it's a short hand, or maybe a double-meaning of the word, not an actual medical description. Just like somebody who is "a little OCD" has none of the symptoms of actual OCD.