image by Martin (lic)Depression can be caused by general medical conditions that affect the body's systems or from long-term illnesses that cause ongoing pain. Symptoms of this condition include:
- information from a person's medical history, physical exam, or lab findings that show depressive symptoms are a direct result of a medical condition
- the symptoms are not better explained by another mental disorder
- the symptoms are causing a lot of stress or problems with school, work, relationships with others, or daily activities.
This diagnosis is particularly important because depression can make recovery from a medical condition more difficult. It also increases the risk of the person attempting and completing suicide.
Endocrine and reproductive system disorders are common sources of depressive symptoms. For example, the thyroid, an endocrine gland located in the neck, produces thyroid hormone. People with low levels of thyroid hormone (a condition called hypothyroidism) often experience fatigue, weight gain, irritability, memory loss, and low mood. Treating this condition often reduces depression. Cushing's syndrome, a hormonal disorder caused by long-term exposure of the body's tissues to high levels of the hormone cortisol, can also cause depressive symptoms.
The number of other medical conditions that have been implicated as causes of depression is staggering. This includes conditions such as:
- brain disorders such as Parkinson's disease, Huntington's disease, multiple sclerosis, and Alzheimer's disease
- metabolic conditions (e.g. vitamin B12 deficiency)
- autoimmune conditions (e.g., lupus and rheumatoid arthritis)
- viral or other infections (hepatitis, mononucleosis, herpes)
- back pain
- certain cancers (e.g., pancreatic)
Day-to-day living with these complicated and sometimes painful diseases can be very difficult. The person may have to deal with many medical appointments, multiple medications that have to be taken at different times throughout the day, and changing their daily activities because of tiredness or pain. For example, a person with severe arthritis may become depressed just from the pain involved in getting dressed each day.
Risk for developing this condition appears to be highest among those who suffer a stroke in which depression can appear within weeks to months.
To get the proper treatment, it is important for the clinician to rule out:
- other depressive disorders that are not caused by a medical condition
- medication-caused depressive disorder
- conditions related to the adjustment involved after the start of a major medical condition has been diagnosed.