Languishing
One researcher's word for the flat middle. Not depressed, not doing well either.
Languishing is the name a US researcher, Keyes, gave to a flat state that isn't depression but isn't good mental health either. In his survey of 3,032 US adults, 12.1 per cent fit his definition, and they were more likely to have had depression in the same year. Evidence: decent
It's one researcher's definition, from one survey, in one country. The link to depression is a link, not proof that one leads to the other. It's a useful word. It isn't a diagnosis.
Why it matters
It names the stretch where nothing is wrong enough to mention and nothing is right. Use it to notice where you are, not to talk yourself out of a doctor. If it's been weeks, with sleep or appetite off, go through the two questions.