Hi Ouch,

Yes, sometimes Lithium is used to treat severe depression. It can be added to other antidepressants if you're not responding, especially if you're struggling with suicidal thoughts...apparently sometimes it can help. I was on it this winter myself for those reasons. As others have said, if you have additional questions, it's good to contact your physician about it, but prescribing Lithium doesn't necessarily mean that they think you are bipolar. It can indeed be used to treat depression.

Take care,
ErinBear