C-reactive protein, interleukin-6, soluble tumor necrosis factor α receptor 2 and incident clinical depression.
BACKGROUND
Despite an extensive literature on the role of inflammation and depression, few studies have evaluated the association between inflammatory biomarkers and depression in a prospective manner, and results are inconclusive.


METHODS
We conducted a prospective analysis of blood levels of CRP, IL-6 and TNFα-R2 in 4756 women participating in the Nurses׳ Health Study who donated blood in 1990 and were depression-free up to 1996. Participants were followed between 1996 and 2008 for reports of clinical diagnosis depression or antidepressant use. Additionally, we conducted cross-sectional analyses for CRP, IL-6 and TNFα-R2 and antidepressant use at time of blood draw.


RESULTS
After adjustment for body mass index, menopause status, use of anti-inflammatory drugs and other covariates, no significant associations between CRP, IL-6 and TNFα-R2 and incident depression were observed after a follow-up of 6-18 years. However, menopause status appears to modify the association between IL-6 and depression risk. In cross-sectional analyses, TNFα-R2 was associated with antidepressant use (OR=1.96, 95% CI=1.23-3.13, P-trend=0.001), but no significant associations were found for CRP and IL-6.


CONCLUSIONS
Depression diagnosis was first assessed in 1996, 6 years after blood draw. However the biomarkers have high within-person correlations with measurements 4 years apart.


CONCLUSIONS
Blood levels of CRP, IL-6 and TNFα-R2 were not associated with incident depression over a follow-up of 6-18 years. In cross-sectional analyses, antidepressant use may be associated with higher levels of TNFα-R2 but no associations with depression or antidepressant use were observed in the prospective analysis.
Department of Nutrition, Harvard School of Public Health, Boston, MA, USA; Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA. Electronic address: pchocano@hsph.harvard.edu.
Patricia O
PO
Chocano-Bedoya
Department of Nutrition, Harvard School of Public Health, Boston, MA, USA.
Fariba
F
Mirzaei
Department of Nutrition, Harvard School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women׳s Hospital and Harvard Medical School, Boston, MA, USA.
Eilis J
EJ
O'Reilly
Department of Nutrition, Harvard School of Public Health, Boston, MA, USA; Department of Social and Preventive Medicine, Laval University, Québec, Canada.
Michel
M
Lucas
Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women׳s Hospital and Harvard Medical School, Boston, MA, USA; Department of Medicine, Brigham and Women׳s Hospital and Harvard Medical School, Boston, MA, USA; Department of Psychiatry, Brigham and Women׳s Hospital and Harvard Medical School, Boston, MA, USA.
Olivia I
OI
Okereke
Department of Nutrition, Harvard School of Public Health, Boston, MA, USA; Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women׳s Hospital and Harvard Medical School, Boston, MA, USA.
Frank B
FB
Hu
Department of Nutrition, Harvard School of Public Health, Boston, MA, USA; Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women׳s Hospital and Harvard Medical School, Boston, MA, USA.
Eric B
EB
Rimm
Department of Nutrition, Harvard School of Public Health, Boston, MA, USA; Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women׳s Hospital and Harvard Medical School, Boston, MA, USA.
Alberto
A
Ascherio
D000368:Aged; D000928:Antidepressive Agents / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism*; D003430:Cross-Sectional Studies; D003863:Depression / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood; D015850:Interleukin-6 / Q000097:blood*; D008875:Middle Aged; D011446:Prospective Studies; D047889:Receptors, Tumor Necrosis Factor, Type II / Q000097:blood*
D000928:Antidepressive Agents; D015415:Biomarkers; C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6; D047889:Receptors, Tumor Necrosis Factor, Type II; C415902:TNFRSF1B protein, human; D002097:C-Reactive Protein
C-reactive protein; Depression; Inflammation; Interleukin-6; Prospective study; Soluble tumor necrosis factor – receptor 2