Melancholy "... discolours everything ... it deprives the soul of all its aspirations, enchains its powers, and produces a mental paralysis.... Melancholy clips [our] wings..."
This is true. While there are truly times of sadness and grief ... and yes, depression too ... ongoing melancholy does clip our spiritual wings. It is not "spiritual" to be glum and super-serious! And joy and gladness are results of life in Christ, not signs of shallowness, so long as their well-spring is our determination--our will--to focus on, to look to Jesus.
"Turn your eyes upon Jesus/ Look full in His wonderful face/ And the things of earth will grow strangely dim/ In the light of his glory and grace."