Medicine would be drugs. Unless you mean in the broad sense of the term.

For me I require a reason behind my happiness, maybe it's my autism I'm not sure, however without a foundation leading to smiles the smiles are lackluster. Just forcing myself to go outside, sit in a nice park, etc. helps place me into opportunities where I can notice things that make me happy bit by bit.
These little things add up. Being at a small time gig, of a band I haven't heard of, being around people who like the same things helps a lot.

I've wanted to see my favourite musicians, and I managed to through perseverance (Corey Taylor is an amazing human being, his outlook definitely rubbed off on me). I wanted to go to Europe, and everyone I knew kept saying "one day", so I decided that "one day" for me was going to be the next. Packed some things and went that weekend to Amsterdam, by myself, and met 3-4 people and we all hung out together for four days and we had such a connection we enjoyed ourselves so much.

If you have an inkling of places or things that would make you happy, perhaps try forcing the first step into it. It's easier said than done, though good luck man.