Comorbidity
Roughly 10% of the U.S. population experiences depression each year. Those suffering from certain medical, psychiatric, or substance abuse problems tend to be afflicted in greater proportions. When two or more medical conditions occur simultaneously, they are said to be comorbid. Depression and medical or other psychiatric illness may be linked biologically, psychologically, or may be entirely unrelated. In some instances a medical disorder contributes biologically to depression, as with diabetes or hypothyroidism (underactive thyroid gland).
Poor prognosis, pain, or incapacity caused by an illness or its treatment may cause a psychological reaction that induces depression in some ill people. Cancer, heart attack, and stroke victims experience depression in greater proportions than their healthy counterparts.
Certain medications used in the treatment of medical conditions may induce or contribute to depressive symptoms. Some of the alleged links between certain medications and depression are based on a small number of cases and may not be generalized to the majority of people taking those medications. However, evidence supports a potential link between depressive symptoms and certain types of prescription medications. These are:
- corticosteroids
- calcium channel blockers
- digoxin
- antihyperlipidemic agents
- angiotensin converting enzyme inhibitors
- sedative hypnotics
- psychostimulants
- certain hormones
