Depression often co-exists with other mental or physical illnesses. Substance abuse, anxiety disorders and eating disorders are particularly common conditions that may be worsened by depression. A great deal of research is currently underway into the relationship between depression and physical illnesses. Several recent studies have noted that when co-existing depression is treated, prognoses are substantially improved for conditions such as heart disease, AIDS, cancer, Parkinson’s disease and diabetes. It is important to tell your doctor about all of the symptoms you are experiencing and all other illnesses for which you are receiving treatment. For more information, click here.