Saturday 11 November 2017

Relationship between depression and elevated CRP levels

When the inflammatory marker CRP is elevated, we particularly think about low-grade inflammation and diseases of affluence such as obesity. But an elevated CRP value has also been found to be related to a higher risk of psychological symptoms and depression.


Elevated levels of the inflammatory marker CRP (C-reactive protein) are a characteristic of low-grade inflammation. This process plays an important role in many diseases of affluence, including cardiovascular disease, obesity, type 2 diabetes and auto-immune diseases. But a large-scale metastudy has also revealed that low-grade inflammation also plays a role in depression.


73,000 trial subjects

For the study, the results of two past studies were combined, resulting in a total population of 73,000 trial subjects. The participants were aged between 20 and 100 years. The CRP concentration of the trial subjects was known and psychological symptoms were enquired about using questionnaires. Whether or not someone suffered from depression was based on whether they used antidepressants.


An elevated CRP value was found to be related to an increased risk of psychological symptoms and depression: for the self-reported use of antidepressants, the risk of depression with a CRP value of at least 10 mg/l was almost three times higher in comparison to a CRP value not exceeding 1 mg/l. If the CRP level was between 1 and 3 mg/l, the risk of depression increased significantly by 38%, whilst if the CRP value was between 3 and 10 mg/l the risk of depression doubled. The risk of a hospital admission because of depression was twice as high when the CRP level was 10 mg/l or higher.


Following an inflammation, the amount of CRP protein in the body increased within a couple of hours. When there was a low-grade inflammation, a small amount of CRP protein continuously circulated in the blood. The level of CRP protein that was measured is a measure of the inflammatory load in the body and can therefore show whether your client does indeed suffer from low-grade inflammation.  



Wium-Andersen MK, Ørsted DD, [..], Nordestgaard BG. Elevated C-reactive protein levels, psychological distress, and depression in 73, 131 individuals. JAMA Psychiatry 2013; 70(2):176-84