The challenge of comorbid disorders in patients with depression.

Depression is common in medically ill patients, and it presents a particular challenge to the primary care physician. Depression may exacerbate cardiovascular disease, diabetes, and irritable bowel syndrome. Also, it may cause a poorer prognosis of each of these disorders. It is therefore recommended that depression screening be incorporated into a treatment plan for all these conditions, because treatment of depressive symptoms will improve patient quality of life and the outcome of other comorbid illness.