Zoloft is a brand name for sertraline, a selective serotonin reuptake inhibitor (SSRI) developed by Pfizer. Approved by the FDA in 1991, Zoloft is commonly prescribed to treat major depressive disorder, anxiety disorders, obsessive-compulsive disorder (OCD), panic disorder, and post-traumatic stress disorder (PTSD). It works by increasing levels of serotonin in the brain, which helps improve mood and reduce anxiety. Zoloft is known for its effectiveness in managing these conditions, with a relatively favorable side effect profile compared to some other antidepressants. Common side effects can include nausea, insomnia, and sexual dysfunction.