Canan et al J Clin Med Res • 2009;1(5):290-291 Table 1. Baseline And Post Escitalopram Treatment Values of White Blood Cells Before treatment After treatment WBC NEUT LYMPH MONO EO BASO 6.93 ± 2.43 4.46 ± 2.05 1.82 ± 0.55 0.57 ± 0.20 0.20 ± 0.41 0.19 ± 0.01 6.78 ±1.35 3.97 ± 0.94 2.08 ± 0.49 1.61 ± 0.68 0.30 ± 0.66 0.20 ± 0.01 p value 0.732 0.218 0.008 0.167 0.644 0.751 White Blood Cell (WBC), neutrophil (NEUT), lymphocyte (LYMPH), monocyte (MONO), eosinophyl (EO), and basophyl (BASO). tween basal and posttreatment variables. Data are expressed as mean ± standart deviation. Statistical significance was de- fined as p < 0.05. erative effect. According to these results, the possible treat- ment of depression with escitalopram must be carried out with caution, in patients with immunological disturbances. Results At the end of the study, LYMPH was found to be significant- ly decreased compared to the baseline value after 8 weeks treatment with escitalopram (p < 0.001). There was not a significant change in WBC, NEUT, MONO, EO, and BASO parameters (Table 1). Discussion Numerous observations indicate that the changes in the state of the central nervous system, particularly of the mood lev- el, are accompanied by the changes in immunological sta- tus of the organism, and conversely, the diseases involving immunological responses influence behavior [4]. Serotonin was found to modulate immunological responses such as proliferation of lymphocytes induced by mitogens [5, 6]. Serotonin in lymphatic organs derives from macrophages, lymphocytes, basophils, mast cells and blood platelets, and also, secondarily, the noradrenergic sympathetic nerve end- ings, that are capable of serotonin reuptake [7]. Available data demonstrate that serotonin affects the immunological responses both in vitro and in vivo conditions, and its action is biphasic: low concentrations of serotonin stimulate, while its high levels suppress the immunological system. Thus, serotonin may be regarded as an autocrine and paracrine modulator of immunological responses [5, 6]. The present study has shown that escitalopram increased LYMPH in patients with major depression. This study in- dicates that the escitalopram, a selective serotonon reuptike inhibitor antidepressant, seems to have a lymphocyte prolif- Conflict of interests The authors declare no conflict of interests. References 1. Maes M. Evidence for an immune response in major de- pression: a review and hypothesis. Prog Neuropsycho- pharmacol Biol Psychiatry 1995;19(1):11-38. 2. Kubera M, Maes M. Serotonin-immune interactions in major depression. In: Patterson P, Kordon C, Christen Y. eds. Neuro-immune Interactions in Neurologic and Psy- chiatric Disorders. Springer-Verlag, Berlin, Heidelberg, 2000:79-87. 3. Montgomery SA, Asberg M. A new depression scale designed to be sensitive to change. Br J Psychiatry 1979;134(382-389. 4. Leonard BE. The immune system, depression and the action of antidepressants. Prog Neuropsychopharmacol Biol Psychiatry 2001;25(4):767-780. 5. Kut JL, Young MR, Crayton JW, Wright MA, Young ME. Regulation of murine T-lymphocyte function by spleen cell-derived and exogenous serotonin. Immuno- pharmacol Immunotoxicol 1992;14(4):783-796. 6. Young MR, Kut JL, Coogan MP, Wright MA, Young ME, Matthews J. Stimulation of splenic T-lymphocyte function by endogenous serotonin and by low-dose ex- ogenous serotonin. Immunology 1993;80(3):395-400. 7. Mossner R, Lesch KP. Role of serotonin in the immune system and in neuroimmune interactions. Brain Behav Immun 1998;12(4):249-271. Articles © The authors, Journal compilation © J Clin Med Res and Elmer Press™, www.jocmr.org 291