Depressive Disorder , Panic Disorder , Obsessive-Compulsive Disorder , Social Anxiety Disorder , Premenstrual Dysphoric Disorder , Post Traumatic Stress Disorder and for acute and chronic PTSD . It is also unofficially used to treat Fibromyalgia , Arthritis , Chronic Fatigue , Multiple Sclerosis , Lupus , headaches , Irritable Bowel