Is fibromyalgia a legit disease, or all psychological?

Fibromyalgia is definitely legitimate and physical. It's not defined as a disease because scientists do not know what causes it, so it is considered a syndrome. Depression is one of the symptoms along with about 25 other symptoms a person may suffer from with this illness. The FDA has approved 3 drugs specifically for the treatment of Fibromyalgia. I have the illness and have suffered from 24 out of the 25 symptoms. Some of symptoms have lessened over time, but other symptoms have not. Depression came along with it. My depression has been effectively and easily treated, yet I still have Fibromyalgia. I wish it were as simple as depression being the cause, then I wouldn't have to suffer from this miserable disease anymore.