Interleukin-6 and verbal memory in recurrent major depressive disorder

OBJECTIVE: To evaluate the possible association between peripheral levels of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) with immediate and delayed verbal recall in a group of recurrent depressed women.METHODS: Logical Memory Subtests of the Wechsler Memory Scale - Revised was administered to 30 patients with recurrent major depressive disorder with no clinical and psychiatric comorbidities. Blood samples were collected from 8:00 am to 9:00 am, before memory assessments. Plasma was stored and ELISA assay was used to detect IL-6 and TNF-alpha levels.RESULTS: There was a statistically significant association between IL-6 levels and immediate verbal recall (IVR) (B=-0.787, p=0.000) and delayed verbal recall (DVR) (B=-0.695,p=0.001) even after controlling for age, depression severity and body mass index.CONCLUSION: The results of this study indicated that low performances in IVR and DVR are associated with higher IL-6 levels in women with recurrent MDD. The results of this study suggest the existence of an association between inflammatory imbalance and cognitive impairment in MDD. Pontifical Catholic Univ Rio Grande Sul PUCRS, Postgrad Program Psychol Human Cognit, Dev Cognit Neurosci Res Grp, Porto Alegre, RS, Brazil Pontificia Univ Catolica Rio Grande do Sul, Biomed Res Inst, Lab Cellular & Mol Immunol, Porto Alegre, RS, Brazil Fed Univ Hlth Sci Porto Alegre, Postgrad Program Hlth Sci, Porto Alegre, RS, Brazil Univ Fed Minas Gerais, Sch Med, Dept Internal Med, Belo Horizonte, MG, Brazil Univ Fed Sao Paulo, Dept Psychiat, Sao Paulo, Brazil Univ Fed Sao Paulo, Dept Psychiat, Sao Paulo, Brazil Web of Science