Paxil is useful for many mood problems including: depression, obsessive-compulsive disorder (OCD), panic disorder, social anxiety disorder, generalized anxiety disorder, post-traumatic stress disorder (PTSD), and premenstrual dysphoric disorder. Paxil® is a trade name for paroxetine or paroxetine hydrochloride, a selective serotonin reuptake inhibitor (SSRI) antidepressant.