The general rule is that dmt will probably intensity, or even perhaps compound beyond comprehension, whatever feelings you may be having, but that is not always the case. There have been times when I have been feeling sad, and the spice revealed something surprisingly good, and then I felt better. Or there have been times when I thought I felt really good, and was expecting a a good trip, but it brought me down and left me thinking, "damn why did I do that?". But that is usually not the case.
There have been times when I smoked spice when I was feeling really bad, and I experienced being murdered over and over again, replaying scenes in my head of people I have seen murdered (on the internet), and thought I was the person being murdered. There's a video on the net of a guy in a suit in a meeting shoots himself in the head, and all his blood pours out his nose. In the trip, I had no idea if I was that guy, or if I was someone else. I thought, "either I'm the guy who killed himself, and I'll never wake up from this, or I smoked spice and I'm disoriented". After a few minutes I was thankful to realize that I just smoked spice.
Or, I have flashback experiences from my own life except they take on a freakish, other worldly quality. One time when I was really sad about being rejected by a girl I love, I smoked spice that night, and experienced being sucked in to a black hole, and swirling all around me was her spirit laughing at me and telling me that I will never be loved, that I gave up my soul trying to court her, and she consumed it, and there is nothing left to my existence except her laughing at me and lording it over me that I am nothing.
Other times I'm not feeling very well, and the spice like resets my brain or something, and I'm like.... death? whatever. Everything is fine. My oh my this drug will cause one to experience every emotion on the map and beyond. I do notice that trips are not the same as when I first started taking it. Before the themes were almost always other worldly, but now trips often become very emotional and relate to my personal life. Maybe I should stop taking l-dopa, I don't know if the increased dopamine has a fucked up effect with psychedelics.