His C should not be the one making a diagnosis,although they may have a good idea. My D23 is bipolar, and my S22 is ADD so I know what you mean. Has he given you any reasons why he is unhappy? Have you gone for any MC? If he is depressed just understand that there is really nothing you can do. Other than work on yourself you can not cure him or make him get undepressed, he has to come to that realization by himself. A depressed person has trouble doing that.
You can not control him. Only you can control yourself and you are responsible only for your own happiness.
