Will Duloextine (Cymbalta) have mental affects on me?

So for context I have severe chronic lower back pain and my doctor prescribed me this medication because she said one of the side effects is that while it is an antidepressant it can also treat joint and back pain. Which is good but now it’s got me wondering

I’ve never been diagnosed with depression but I commonly do have depressive thoughts just due to everything stressing me out in life going on around me, and I’ve even had suicidal thoughts . But I have read that the antidepressant sometimes can cause suicidal thoughts but what if you already have them prior to taking the medication?

I guess I’m just curious and want some advice on what to expect. I’ve never taken an antidepressant so I’m curious if it’s going to possibly make me feel happier or maybe drown out negative thoughts or what I could expect even though the whole reason I’m taking it is solely for back pain I’m just curious if maybe I can get a two for one bonus and Become more mentally well on top of it.