I don't know what I'm talking about you say?
There are only -three- indications that I know (and I keep up with medical news like a junkie--LOL) of that are supported by high-quality evidence.
1.) Nausea/Vomiting:
I think it'd be efficacious in any condition that has nausea as a symptom, the way a lot of anti-emetics are used off-label (like Zofran.) However, its most well-documented use is in counteracting cancer chemotherapy-induced nausea and vomiting, a purpose for which it is not only well-supported by the evidence, but seems to be better than anything else we have at the moment.
2.) Extreme Weight Loss:
The two settings in which it has been most often studied is for extreme weight loss associated with cancer and end-stage HIV/AID. All the best studies show that it definitely helps patients get their appettite back and gain weight. I'm not sure if it decreases all-cause mortality in these patient populations, but that would be an interesting question to study.
3.) Chronic And Neuropathic Pain:
Both of these types of pain are extremely challenging and difficult to treat by traditional painkillers. It not only seems to be efficacious in these settings, but the beautiful thing is that it seems to have few side-effects, few drug interactions, and there does not seem to be development of tolerance.
I lived in California, and I can't tell you how many stoners out there have "pot cards." They don't need them (my opinion). What cracks me up is that I've done a lot of volunteer work with addicts (in general) and if you offer them a psychotropic and say, "This will ease your distress and symptoms, help you recover, and keep your cravings at bay," they react as if you're giving them poison! They'll pump ethanol into their stomachs until their livers are green, bloated and covered in scars. They'll consume methamphetamine, which destroys dopaminergic neurons, has now been shown to trigger or unmask psychotic conditions, and is used in the laboratory to give Parkinson's to monkeys--as a standard lab procedure for studies of Parkinson's disease! They'll gladly inhale polyaromatic hydrocarbons and CO, along with dozens of other poisons. They'll inject all kinds of sh!t into their veins.