Low vitamin D is associated with negative and depressive symptoms in psychotic disorders

• Published in: Schizophrenia research 2016-12, Vol.178 (1-3), p.44-49
• Main Authors: Nerhus, Mari, Berg, Akiah O, Kvitland, Levi R, Dieset, Ingrid, Hope, Sigrun, Dahl, Sandra R, Weibell, Melissa A, Romm, Kristin L, Faerden, Ann, Andreassen, Ole A, Melle, Ingrid
• Format: Article
• Language: English
• Subjects: Adult; Biomarkers - blood; Cross-Sectional Studies; Depression - blood; Depression - complications; Depression - immunology; Female; Humans; Inflammation; Interview, Psychological; Male; Psychiatric Status Rating Scales; Psychiatry; Psychosis; Psychotic Disorders - blood; Psychotic Disorders - complications; Psychotic Disorders - immunology; Psychotic Disorders - psychology; Regression Analysis; S-25(OH)D; Schizophrenia; Schizophrenia - blood; Schizophrenia - complications; Schizophrenia - immunology; Schizophrenic Psychology; Suicidal Ideation; Symptomatology; Vitamin D Deficiency - complications; Vitamin D Deficiency - immunology; Vitamin D Deficiency - psychology
• ISSN: 0920-9964; 1573-2509
• DOI: 10.1016/j.schres.2016.08.024

Abstract Background There are indications that low S-25(OH)D is associated with increased disease severity in psychotic disorder. Our first aim was to investigate the relations between low S-25(OH)D and positive, negative and depressive symptoms. Our second aim was to explore if associations between S-25(OH)D and symptoms were influenced by levels of inflammatory markers. Methods Participants (N = 358) with a medical history of one or more psychotic episodes were recruited. Current symptomatology was assessed by The Structured Interview for the Positive and Negative Syndrome Scaleanalyzed by a five-factor model. The Calgary Depression Scale for Schizophrenia was used to assess depression and suicidal ideation. Blood samples were analyzed for S-25(OH)D, CRP, sTNF-R1, IL-Ra and OPG. We performed bivariate correlations and multiple regression models to evaluate the effect of S-25(OH)D on the outcomes. Results Low S-25(OH)D was significantly associated with negative symptoms (adjusted R2 = 0.113, F(6,357) = 8.58, p < 0.001) and with depression (adjusted R2 = 0.045, F(4,357) = 5.233, p < 0.001) when adjusting for possible confounding factors (i.e. gender, education, diagnose, hospitalization status, ethnicity, season and thyroid status). CRP was correlated with both S-25(OH)D (rho = − 0.13, p = 0.02) and negative symptoms (rho = 0.14, p = 0.01), but did not act as a mediator. The correlations between S-25(OH)D and the inflammatory markers sTNF-R1, IL-Ra and OPG were not significant. Conclusion There is a strong association between low S-25(OH)D and higher negative and depressive symptoms in psychotic disorders. Randomized controlled trials should be performed to investigate the effect of vitamin D supplementation as adjuvant treatment strategy in patients with prominent negative or depressive symptoms.