Depression can cause thoughts that stem from a form of self-hate. Harming yourself, suicide, husband doesn't love you, etc.- they are intrusive, however are part of your unconscious mind- another words they ARE coming from somewhere you may just have to dig deep to find the root of the problem. That is why they keep persisting.

Of course, a med change may help this, but I found with my own past depressions that med changes were not the only changes that were needed to end the thoughts. Sometimes it was that my life had become unmanageable, or I needed to change my thinking patterns or I needed to make a life change that I had been holding back from, etc, etc...