Zoloft (sertraline hydrochloride), an antidepressant, is a class of drugs called selective serotonin reuptake inhibitors (SSRIs). Pfizer started manufacturing Sertraline in the early '90s. In 1999, the Food and Drug Administration (FDA) approved it as an antidepressant. This drug affects chemicals in the brain that may become unbalanced and cause depression, panic, anxiety, or obsessive-compulsive symptoms. In 2013, it was the most prescribed antidepressant. It is administered both in adults and children to treat conditions such as depression, obsessive-compulsive disorder, post-traumatic stress disorder, and anxiety.