Elevated levels of a blood protein linked to inflammatory disease appear to be associated with an increased risk of developing depression, a new study reveals.

Past findings suggest that low-grade systemic inflammation may contribute to the development of depression, but Danish scientists recently revealed that people with high levels of C-reactive protein, commonly used as a marker of inflammation to assess a person's risk for heart disease, are significantly more likely to suffer from psychological distress and depression.

Lead researcher Dr. Marie Kim Wium-Andersen, of Herlev Hospital and Copenhagen University Hospital in Denmark, looked at medical data from 73,131 Danish people between the ages of 20 and 100 and found an association between elevated CRP levels and in an increased risk for psychological distress and depression.

Researchers found that people with higher CRP levels were more likely to report to have taken antidepressants and to have been hospitalized for depression. CRP levels that exceed 10 mg/L are generally believed to be an indicator for inflammatory disease.

For example people with CRP levels between 1.01 to 3 mg/L are 38 percent more likely to report antidepressant use. People with CRP levels between 3.01 to 10 mg/L were more than twice as likely to report using antidepressants and those whose CRP reading exceeds 10 mg/L are nearly 3 times more likely to report the same.

While more research is needed, researchers say that the latest findings "support the initiation of intervention studies to examine whether adding anti-inflammatory drugs to antidepressants for treatment of depression will improve outcome," according to PsychCentral.com.

The findings are published in the journal Archives of General Psychiatry.