I think most psychedelics can be useful for that. They can also be harmful and destabilizing. It all depends on when and how you use them.
I think there's a relative consensus here that the idea prompted by the pharmaceutical companies interested in psychedelics that it's "one and done", that the substance itself cures you and a single dose may do it, is very questionable. There may be a few cases like that but it's not how it usually goes.
As someone who was in a very deep, dark depression for years, my perspective is that psychedelics can help you get insight into your situation and temporarily loosen the grip of learned mental patterns, habits, etc. But then it's up to you what to do with those insights and higher mental flexibility.
IMO the main path out of depression is the same, regardless of whether you're using psychedelics or not. Psychedelics may help and I encourage you to try if you think that may be the case. Just avoid putting too many expectations on the substance itself. It won't cure your depression: you will. Same goes for therapy or other techniques. Psychedelics deserve special caution because they're very powerful. As always, a higher potential benefit comes hand in hand with a higher risk.
Specifically with DMT, I think that you may find more helpful oral DMT in Ayahuasca or pharmahuasca. Or at least smoked DMT combined with harmalas, be it as changa or by taking oral harmalas. Adding harmalas tends to make the experience slower (and thus easier to process and interact with) and of a more personal nature.
If you decide to go for smoked DMT only, I'd encourage you to also explore the lower doses, as again those may be more personal and more relevant to your depression. Of course, this doesn't mean you shouldn't also go for some higher doses. Mystical experiences can be helpful in shifting your mind.
All the best luck in your path, and I hope to see you around here and read about your process
