obsessive compulsive disorde
"So far this is the best medication I've been on for Obsessive Compulsive Disorder. I have obsessive thoughts and ruminating as my compulsion and it was totally debilitating before. I was on mirtazapine for a while but felt emotionless and still had a lot of OCD-"crashes". Switched to Fluvox because mirtazapine made me gain a lot of weight. Finally losing weight now and have a normal appetite again! Obliterates obsessive thoughts and makes me feel really happy, plus I have all my strong emotions back, feeling more "me" again. 
Frustrating side effect in insomnia (most nights I wake up 2-3 times for 30 mins at least and sleep very restlessly) but the headaches and nausea have both passed, so hopefully this will also pass."