It is wisest to discuss one of the therapies with your psychiatrist first. Yes, it could also be trauma-related.
Lithium is very effective for mood stabilization.
It's mostly a standard treatment for bipolar disorder, especially mania and mood swings but it also can reduce depressive episodes when other medications aren't enough.
Lithium is one of the few medications proven to lower suicidal thoughts and behaviors, independent of its mood effects compared to Lexapro, where it actually increases the risk of suicidal thoughts. So this needs to be moderated well by a psychiatrist.
Cons of Lithium is that it requires regular blood monitoring for lithium levels, kidney function, thyroid function. It's also more prone to overdose or sudden level changes which can cause nasty side effects.
Which medication works best is ultimately a mather of trial and error, which can take quite some time.
I wish you the best of luck with the choice you make.
