The most common anti depresent medication is called a s s r i, which means select selective seratonan re up take inhibitor. When we use this kind of a drug, essentially what we discover is that people with depression seem to get better. People sort of think about saratoni as kind of like a direct dose response sort of effect. But it's not like doubling our seraton an doubles our happiness. It actually turns on some machinery within ourselves and affects our receptors so that the effect is a little bit more long term.