Hello & Welcome, Troubledteacher.

Regarding long-term or recurring depression (not other types) my experience and observations fill me with pessimism. It's a bit like living on the tundra. Some days - even seasons - will be warmer and others much cooler, but you're still living on the tundra; you can try planting date palms, but it would be more practical developing ice-fishing skills.

Of course, over time you could get so good at ice fishing that you rarely think about the fact you're living on the tundra.

Make yourself at home here. May others with far more optimism reply to you.