I think depression has a purpose and is a rather healthy response to anxiety and lack of sufficient stimulation caused by society not being accommodating enough. Reaching our potential in life requires solving a very difficult puzzle, much planning, a very rational mind, working around obstacles and recovering from overexertion. Depression helps with all that.

The pattern where you get two dissociated extremes where memories are lost is really a problem of the mind: psychological. The problem of our brains being wired differently is really society's problem, so we share it with everyone, and society solves it not by being more accommodating, but by changing us. That is not all that bad, because it allows to work on reintegrating the dissociated parts of ourselves, becoming less dependent and becoming part of those parts of society that are most accommodating.