If depression is psychological, how is it treated with a physical medicine program?

Hope this helps. Exercise: http://www.apa.org/monitor/2011/12/exercise.aspx http://www.mayoclinic.org/diseases-conditions/depression/in-depth/depression-and-exercise/art-20046495 Medications, sleep hygiene, Healthy lifestyle encouragement, pain control, etc.
Exercise. Many studies have demonstrated that physical exercise has been shown to alleviate symptoms of depression. Everything that is "psychological" is happening in the brain. Dividing things into physical and psychological is really not an accurate representation of how the human body works. Even helping a depressed person get out in the fresh air and get a little sun on their face can help.
It isn't psychologic. Most depression is medical. But that doesn't mean an antidepressant is needed. In my practice, i take the time to find the real medical cause of the depression, such as hypothyroidism, nutritional deficiencies or even allergies.