I did notice that once I became addicted to opiates, I could no longer trip on mushrooms. At the time I was on a mission to give away as many trips as I could but once I found myself surrounded by people on opiates, I noticed no one was tripping. Bupe does the same thing to your brain chemistry as opiates so I'm assuming that the chemicals they effect interfere with the hallucinogens. Hopefully someone here can give me the exact science behind that because I've been curious about it too. That was one of the biggest inspirations for me to get off everything all together.
Buprenorphine has no effect on psychedelics at all,you still trip,the difference is that it will take the anxiety away from a trip and therefore soften the edges...Having anxiety on a trip hightens the effects,so this is probably what you are experiencing,a lack of anxiety.
The naltexone in suboxone also has no effect on psychedelics.
I never noticed any difference in intensity of effects when I combined heroin and 2c-e, although the trip still ended up feeling less mentally intense because I was so mellowed out from the down.
Suboxone may not physiologically interfere with the action of psyches, but it can definitely change the mindset you have entering/during the trip