Zoloft is a brand of sertraline hydrochloride, Doxycycline monohydrate 100mg an antidepressant drug used for the treatment of depression, obsessive compulsive disorder, and anxiety disorders. Zoloft was approved by the FDA in 1991 for treating depression and Doxycycline monohydrate 100mg then for treating obsessive compulsive disorder in 2002.