title: Association between C-reactive protein (CRP) with depression symptom severity and specific depressive symptoms in major depression.
abstract: BACKGROUND
  Population-based studies have associated inflammation, particularly higher C-reactive protein (CRP), with depressive severity, but clinical trials in major depressive disorder were rather non-specific without examining the role of gender. We aimed to investigate the association between CRP and overall depression severity including specific depressive symptoms and to examine potential gender differences.
  
  
  METHODS
  We included 231 individuals with major depressive disorder from the Genome-Based Therapeutics Drugs for Depression (GENDEP) study. At baseline, we assessed high-sensitivity CRP levels and psychopathology with the Montgomery Aasberg Depression Rating Scale (MADRS). We performed linear regression analyses to investigate the association between baseline CRP levels with overall MADRS severity and specific symptoms at baseline and adjusted for age, gender, anti-inflammatory and psychotropic drug treatment, body mass index, smoking, inflammatory diseases, and recruitment center.
  
  
  RESULTS
  Higher CRP levels were significantly associated with greater overall MADRS symptom severity (p=0.02), which was significant among women (p=0.02) but not among men (p=0.68). Among women, higher CRP was associated with increased severity on observed mood, cognitive symptoms, interest-activity, and suicidality, but we found no significant associations among men. Interaction analyses showed no significant gender differences on the overall MADRS score or specific symptoms.
  
  
  CONCLUSIONS
  Our results support the sickness syndrome theory suggesting that chronic low-grade inflammation may be associated with a subtype of depression. The potential gender differences in psychopathology may be explained by biological and/or psychosocial factors, e.g. differential modulation of immune responses by sex hormones. Clinical studies should investigate symptom-specific and/or gender-specific treatment guided by peripheral inflammatory markers.
authors.affiliation: Aarhus University Hospital, Risskov, Psychosis Research Unit, Aarhus, Denmark; iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus, Denmark. Electronic address: karkoe@rm.dk.
authors.forename: Ole
authors.initials: O
authors.lastname: Köhler-Forsberg
authors.affiliation: iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus, Denmark; Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Denmark.
authors.forename: Henriette N
authors.initials: HN
authors.lastname: Buttenschøn
authors.affiliation: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK.
authors.forename: Katherine E
authors.initials: KE
authors.lastname: Tansey
authors.affiliation: Department of Psychiatry, University of Bonn, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Maier
authors.affiliation: Laboratory of Psychiatric Genetics, Department of Psychiatry, Poznan University of Medical Sciences, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Hauser
authors.affiliation: University Psychiatric Clinic, Ljubljana, Slovenia.
authors.forename: Mojca Zvezdana
authors.initials: MZ
authors.lastname: Dernovsek
authors.affiliation: Croatian Institute for Brain Research, Medical School, University of Zagreb, Croatia.
authors.forename: Neven
authors.initials: N
authors.lastname: Henigsberg
authors.affiliation: Laboratoire de Psychologie Médicale, Université Libre de Bruxelles; Psy Pluriel - Centre Européen de Psychologie Médicale, Belgium.
authors.forename: Daniel
authors.initials: D
authors.lastname: Souery
authors.affiliation: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK.
authors.forename: Anne
authors.initials: A
authors.lastname: Farmer
authors.affiliation: Department of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
authors.forename: Marcella
authors.initials: M
authors.lastname: Rietschel
authors.affiliation: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: McGuffin
authors.affiliation: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK; Departments of Psychiatry and Medical Genetics, University of Alberta, Edmonton, AB, Canada.
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Aitchison
authors.affiliation: Department of Psychiatry, Dalhousie University, Halifax, N.S., Canada.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Uher
authors.affiliation: Aarhus University Hospital, Risskov, Psychosis Research Unit, Aarhus, Denmark; iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus, Denmark.
authors.forename: Ole
authors.initials: O
authors.lastname: Mors
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis*; D003863:Depression / Q000097:blood / Q000175:diagnosis*; D003865:Major Depressive Disorder / Q000097:blood / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors; D012720:Severity of Illness Index; D012737:Sex Factors
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein