Depression Causes What Condition_symptoms What Causes The Chemical Imbalances That Lead To Depression?

What causes the chemical imbalances that lead to depression? - depression causes what condition_symptoms

The medical community is often argued that a major cause of depression a chemical imbalance. However, there is hardly any discussion about the causes of chemical imbalance. I wonder what it could be. I have my own ideas, but I would listen to the other on the probable causes.