title: In-hospital levels of C-reactive protein and IL-6 predict post-operative depressive symptoms among patients undergoing total knee replacement surgery.
abstract: Behavioral changes observed following immune system activation are similar to many of the hallmark symptoms of major depressive disorder (MDD), including appetite change, lethargy, fatigue, negative mood and anhedonia. Acute phase proteins, such as interleukin-6 (IL-6) and C-reactive protein (CRP) have been implicated in the production of sickness behavior, and research has revealed significant differences in the levels of these acute phase proteins between depressed and non-depressed individuals. The current study examined whether early post-operative IL-6 and CRP levels predicted subsequent depressive symptoms in 110 patients undergoing total knee replacement surgery (TKR). In-hospital levels of IL-6 and CRP predicted depressive symptoms at three-months following surgery, as indicated by significant main effects and a significant interaction term. Specifically, lower levels of in-hospital CRP and higher levels of IL-6 in-hospital predicted more depressive symptoms three-months following surgery. The finding that levels of acute phase proteins soon after surgery predict subsequent depressive symptoms, if replicated, extends prior research on the relationships between IL-6, CRP, and depression. Further, this predictive relationship suggests the possibility of early identification of individuals at risk for the subsequent development of post-operative depression.
authors: Department of Psychology, Kent State University Stark Campus, N Canton, OH 44720, USA. jcremean@kent.edu
authors: Julie K
authors: JK
authors: Cremeans-Smith
authors: Steve
authors: S
authors: Soehlen
authors: Kenneth
authors: K
authors: Greene
authors: Thomas
authors: T
authors: Alexander
authors: Douglas L
authors: DL
authors: Delahanty
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000523:psychology*; D002097:C-Reactive Protein / Q000378:metabolism*; D016009:Chi-Square Distribution; D003863:Depression / Q000378:metabolism* / Q000523:psychology; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011788:Quality of Life; D012044:Regression Analysis; D012737:Sex Factors; D011795:Surveys and Questionnaires
chemical_list: D015850:Interleukin-6; D002097:C-Reactive Protein