Technically, any chemically induced change of state of mind that doesn’t require a third party to supervise, can be considered self medication.

Morning coffee? Self medication. Going for a jog to feel better? Self medication. Getting blackout drunk on your own? Self medication. Midnight wank when you can’t sleep? Self medication.

You know what’s NOT self medication? Taking shrooms or LSD or any other hallucinogenics with a trip sitter.