Read this, SRH. Marinol does convey some psychoactive effects, but it's a synthetic form of delta-9-THC, not whole cannabis with its other psychoactive and therapeutic components, and so it's not going to feel the same to anyone who uses it as regular smoked cannabis. In fact, it may feel worse. The THC is the compound in weed that can produce bad psychological effects (in some, anxiety and in some particularly vulnerable folks, delusions), whereas cannabidiol, the other main psychoactive component, is the stuff that helps quell anxiety and probably accounts for the mellow part of people's high. In marinol, you won't be getting any CBD, just synthetic THC, which metabolizes in the liver into other related THC compounds that can also cause or aggravate psychological responses. If you read through this NORML info carefully, you'll see that, for medical users, whole cannabis seems to have more therapeutic effect for many people. From what I've heard doctors say, Marinol is an option for people who can't or won't obtain the real stuff.

Marinol vs. Natural Cannabis - NORML