Medicinal uses I support. It doesn't get you addicted, it just acts as a painkiller.
On the subject of addiction, addiction only comes when you have no friends, because in that case marijuana is your friend. The addiction myth (that drugs cause drug addiction) comes because of a certain rat experiment, where a singular rat was kept in a cage with 2 water sources: clean water, and water mixed with marijuana. In this experiment, the rat would drink the marijuana water until it died of an overdose. One scientist saw what was wrong with this experiment: the rat was lonely. So he put that rat with many other rats, and with many toys and pipes to play with. The marijuana water wasn't touched. He concluded that loneliness is what causes addiction.
As for the war on drugs, I think the US of A is missing the point. Instead of trying to take away drugs (and failing miserably), they should go for harm reduction, helping the addict while slowly easing him off drugs.