Lithium

I think everyone pretty much covered it, but . . .

Lithium is typically a treatment for bipolar disorder (though not all forms of bipolar disorder include major depression in their cycles, most do and lithium is certainly more poetic than singing about treatments for major depression-- oh, SSRIs, MAOIs . . . you get the idea, lol), and oftentimes a fear preventing the taking of them is that they'll alter emotions too much, so that one doesn't know themselves anymore; we've let ourselves be defined by our depression. More potent than the fear of the side effects of a specific drug, however, is change, period (which can still be accredited to the drug). As anyone with a long-standing mood disorder can attest to, it IS comfortable to slide back into the old ways of coping, the "familiar darkness." There's definitely a conflict between wanting to get better but fearing the unknown (however unpleasant, it's familiar, and familiarity is always more comfortable).

As for the verses about coming to bed and forgiveness-- I'm not so clear, but my perception right now is that there's someone who's loved her during her darker hours, perhaps because of them. In my experience and observation, depression seems to lead to unusual attachments one otherwise might not have, and so sometimes losing the depression can change or even destroy the relationship.

This is definitely a powerful song, especially in being able to capture this emotion which is more pervasive than I'm sure many suspect.