Depression Caused by Disease

While I was doing research for my term paper, the subject of depression caused by physical illness came up.

It is proven that certain illnesses can cause a patient with that illness to develop depression. Therefore, the patient is now experiencing both a physical and mental illness.

I want to focus this blog post on depression that is seen specifically in patient's with multiple sclerosis (MS).
"Studies have suggested that clinical depression, the severest form of depression, is more frequent among people with MS than it is in the general population or in persons with other chronic, disabling conditions."

The article I am getting the information for this blog post states that there are many reasons why a patient with MS develops clinical depression.

1. The depression may be a reactive response to the diagnosis
• The depression comes as a result of the stress associated with the disease. MS is a chronic disease, that does not have a cure, and can gradually progress to point of permanent disability. 
2. Depression may be caused by the disease itself
• MS is a demyelinating disease, which means that the myelin sheath that surrounds neurons to aid in signal transmission is destroyed over time. If MS destroys the myelin sheaths in the neurons located in the portions of the brain that control emotions, behavioral changes occur. 
3. Depression may be a side effect caused by medications. 
• Corticosteroids are the most commonly prescribed drug in MS when the patient is experiencing an exacerbation of the disease. This occurs in what is called "relapsing-remitting" MS--the most common type of the disease. 
• Corticosteroids are known to cause emotional changes as one of the side-effects.

I am bringing this up, because I have a question.
           --> Should information about mental health that is included in a global campaign distinguish between chronic mental illnesses and mental illnesses that develop as a result of diseases? Is it necessary to educate the public about the differences between them?

My second question is: Should the treatment between the typical depression and depression caused by MS be the same? Or should people with MS have different treatments/interventions?

Any thoughts?

SOURCE: http://www.nationalmssociety.org/Symptoms-Diagnosis/MS-Symptoms/Depression