Zoloft is used for the treatment of depression, obsessive compulsive disorder (OCD), singulair and panic disorder. It is also used off-label to treat social anxiety disorder and premenstrual dysphoric disorder. The exact mechanism that allows Zoloft to combat these affilictions is still not completely understood, however what researchers have noticed is that Zoloft affects the way that serotonin is managed by the human body. Serotonin is part of a drug family known as selective serotonin re-uptake inhibitors (or singulair SSRI's). SSRI's increase the level of serotonin in the brain by inhibiting (not preventing) its breakdown. So why take Zoloft? Because it has fewer side effects than tricyclic antidepressants (TCA's like Elavil and Tofranil). In addition SSRI's are found to be effective in 50% of patients as opposed to a typical placebo response of 32% (mulrow).