Maternal C-reactive protein and schizophrenia.

Abstract

Back to table of contents Previous article Next article Communications and UpdatesFull AccessMaternal C-Reactive Protein and SchizophreniaJean-Paul Selten, M.D., Ph.D. Jim van Os, M.D., Ph.D.Jean-Paul SeltenSearch for more papers by this author, M.D., Ph.D. Jim van OsSearch for more papers by this author, M.D., Ph.D.Published Online:1 Feb 2015https://doi.org/10.1176/appi.ajp.2014.14101299AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail To the Editor: In their article published in the September 2014 issue of the Journal, Sarah Canetta, Ph.D., et al. (1) report that increasing maternal C-reactive protein levels, classified as a continuous variable, were significantly associated with schizophrenia in offspring (adjusted odds ratio reported in the abstract=1.31; 95% confidence interval [CI]=1.10–1.56; adjusted odds ratio reported in the results=1.28; 95% CI=1.07–1.54). The authors interpret this finding from Finland as evidence that maternal inflammation plays a role in this disorder and claim that this inflammation may be due to infections during pregnancy.Surprisingly, the authors do not mention the possibility that the increased C-reactive protein levels were caused by maternal smoking. Levels of C-reactive protein are increased in smokers and remain elevated up to 5 years after cessation (2, 3). This is important because schizophrenia patients are more likely to have a mother who smoked during pregnancy (4). Moreover, smoking during pregnancy is relatively common in Finland. An investigation in 1997 found high prevalence rates among single (30%) and less educated (25%) pregnant women (5). Thus, the increase in maternal C-reactive protein levels may be due, at least in part, to smoking. The same considerations apply to the association, reported by the same research group, between maternal C-reactive protein and autism (6).Finally, it is worth remembering that the results of studies on the relationship between prenatal infection and schizophrenia are not entirely consistent. Birth during the 9-month period after the 1957 influenza pandemic, which produced infection rates of about 50%, was not a risk factor for schizophrenia (7).From the Department of Psychiatry and Psychology, Maastricht University Medical Centre, Maastricht, the Netherlands; and the Department of Psychosis Studies, King’s College London, King’s Health Partners, London.The authors report no financial relationships with commercial interests.References1 Canetta S, Sourander A, Surcel HM, et al.: Elevated maternal C-reactive protein and increased risk of schizophrenia in a national birth cohort. Am J Psychiatry 2014; 171:960–968Link, Google Scholar2 Bazzano LA, He J, Muntner P, et al.: Relationship between cigarette smoking and novel risk factors for cardiovascular disease in the United States. Ann Intern Med 2003; 138:891–897Crossref, Medline, Google Scholar3 Hastie CE, Haw S, Pell JP: Impact of smoking cessation and lifetime exposure on C-reactive protein. Nicotine Tob Res 2008; 10:637–642Crossref, Medline, Google Scholar4 Stathopoulou A, Beratis IN, Beratis S: Prenatal tobacco smoke exposure, risk of schizophrenia, and severity of positive/negative symptoms. Schizophr Res 2013; 148:105–110Crossref, Medline, Google Scholar5 Jaakkola N, Jaakkola MS, Gissler M, et al.: Smoking during pregnancy in Finland: determinants and trends, 1987–1997. Am J Public Health 2001; 91:284–286Crossref, Medline, Google Scholar6 Brown AS, Sourander A, Hinkka-Yli-Salomäki S, et al.: Elevated maternal C-reactive protein and autism in a national birth cohort. Mol Psychiatry 2014; 19:259–264Crossref, Medline, Google Scholar7 Selten JP, Frissen A, Lensvelt-Mulders G, et al.: Schizophrenia and 1957 pandemic of influenza: meta-analysis. Schizophr Bull 2010; 36:219–228Crossref, Medline, Google Scholar FiguresReferencesCited byDetailsCited ByNone Volume 172Issue 2 February 01, 2015Pages 200-200 Metrics PDF download History Accepted 1 November 2014 Published online 1 February 2015 Published in print 1 February 2015