I think it is really a matter of if the combination causes more benefit than issues...drugs certainly can interact but that stuff is usually weighed and some people react differently. For instance there are probably some people that could not take as high a dosage of sedating sort of drugs as me without having adverse effects. I currently just take mirtazapine and valium and still have trazodone prescribed for when I cannot sleep...but for some people taking valium on mirtazapine might make them too drowsy but I tolerate it fine. I also do smoke cannabis on a fairly regular basis and I do drink tea/coffee and other drinks with caffeine....and as far as I can tell everything's interacting alright.

I have certainly tried meds that I feel have made me more emotionally unstable, like SSRI anti-depressants or similar drugs to that...so I do not doubt sometimes certain drugs might make some people worse or bring out more symptoms. Also though even if someone is taking medication that helps...they are still going to experience symptoms from time to time and have bad days, medications don't typically make the issue go away entirely they just are meant to reduce symptoms.

I do not feel like it is ever a good idea to just blindly take any drug prescribed, or just accept whatever is added on without any thinking it through or research....make sure to tell any doctor/psychaitrist all the medications/drugs you use and conditions you have, sometimes people get prescribed too much things or things that have bad interactions because they don't mention it and not every doctor/psychatrist is interconnected so they can miss those things unless the patient/client informs them.