If you keep in mind all of the above, drugs can potentially deepen your insight to help you work through trauma. When you are in "sober" mode, your mind will be in one place. With trauma, sometimes our mind can be stuck in "one perspective", and this one perspective will reinforce certain views of the world and patterns of thinking. Use of drugs can potentially uproot these structures.
At the risk of coming across as a total drug addict (I promise I'm not), I can chip in with a little experience here. I've done a fair amount of reading and some experimentation, once I realised that trying to work through my issues whilst in a constant state of anxiety and depression was getting nowhere.
I initially turned to alcohol for the euphoric effect, finding, after some experimentation, that a specific quantity of a certain beverage helped (white wine in my case), while getting off my face on almost anything else was liable to make me worse - sometimes dangerously so.
I'll buy one bottle when I need it, but there have been times when I'm drinking a bottle every night which I'm not at all keen on doing. Fortunately I've never experienced addiction, but I still value my liver.
Cannabis has long been a life-saver for me, literally. A joint, pipe, or vape with a measured dose has greatly reduced depression and completely stopped the urge to self harm (nearly five years clear now), while cannabis tincture (CBD oil) is a huge help with anxiety.
There is also the bonus of being able to think more deeply and clearly when not distracted by my issues.. I found it best not to get stoned, though, as my mind tends to ramble off in random directions, while I ramble off to the fridge for snacks.
Addiction isn't really an issue either, unless one counts psychological addiction, but that is a whole different issue that has little to do with cannabis itself.
Salvia Divinorum works very well for me, and has been shown to alleviate depression in clinical trials. I don't take it often as it can induce a little ten minute 'trip', which can be interesting, confusing, sometimes somewhat intense.. the last time I tried it, it made me laugh harder than I ever have in my life, and I have no idea what was so funny. But I felt cheerful for several days afterward.
There is also no concern with addiction.
That's the limit of my experience, but there are any number of articles and studies on the beneficial effects of magic mushrooms, MDMA and LSD.
With any substance use, it is best to try to get a balance of views on the benefits, harms and possibility of addiction before trying it - and start small, with a weak dose, just in case you don't find it tolerable.