When you head towards causes of depression, it becomes a tough way as there is no certain cause behind depression. As in the cases of other diseases, there are specific causes.
So it becomes easy to find out medication for such diseases, as if you have diabetes, you can use insulin, if you have appendicitis, surgery can help you, but problem of depression is quite complicated.
As it is not merely cause of chemical imbalance of brain and can’t aid with easy medication. It is believed that it causes with a combination of biological, mental and socio fact.