You've written about your son several times since 2008.  And it's been over a year since you wrote last.  How is he doing?

Schizophrenia and depression are often experienced together.  Although someone with schizophrenia can have just sz symptoms or just depression symptoms.  Although I have schizophrenia (diagnosed 1995) depression has always been my worst problem and appeared at a much earlier age.  Depression has been more constant and more resistant to treatment.

If your son's psychiatrist says he has schizophrenia, then I would trust the doctor, who has been observing your son for a long time.  But misdiagnoses are possible.  For instance, I was first diagnosed with bipolar disorder before the doctor settled for schizophrenia w/major depression.

You can see why someone with sz might tend to be depressed.  It can be a depressing illness at times, for many diverse reasons.  Will your son see a therapist?  Maybe he needs help with structuring his time or developing new interests.

But you can tell him there is hope.  After experiencing depression and sz for a long time, I have finally substantially recovered.  I do have a problem now and then, especially if I skip meds, but ordinarily I live a quite ordinary life.