Mopey

[T]hat is partly owing . . . to young Alexis having been desultory and mopy of late—not taking the interest in his music he did.

He got mopy and melancholy, and couldn't or wouldn't work.

In the 1980s, liberals nursed the fear that we really might be dwelling in an irrelevant cul-de-sac outside of the majority American culture. That kept us sullen and mopey.