Main Entry: psychotropic
:Exerting an effect upon the mind, capable of modifying mental activity, usually applied to drugs that effect the mental state.
: a psychotropic substance (as a drug)
I was trying to differentiate between psychotropic and psychoactive in my mind, as they are synonyms for each other.
The way it plays out in my mind is that a substance can be psychoactive, whereas the effects are psychotropic. Both of these words would therefore come under adjectives, as they are both descriptive and neither is an adverb as it isn't describing and action. Although it isn't describing a verb it is describing something far more abstract than you usual adjective, and thus one could almost argue that it should have a catergory all of it's own (well I'm sure there are others that would also fit into this category, but I'm sure you get what I mean.)
What I think I'm trying to say is that while Psychoactive seems to describe the substance, Psychotropic seems to be more a description of the effects. I know that in 90% of conversations (just like 90% of statistics are made up on the spot) both terms can be easily exchanged, and the more I think about it the more confused and less certain I become.
Right, that's enough random ramblings from me