LITHIUM IN AFFECTIVE DISORDER AND GFR treatment may not be able to detect a subtle progressive decline in GFR. As opposed to cross sectional studies, long term prospective studies in patients on lithium establish age related decline in GFR rather than a clear relationship between lithium exposure and GFR. Although, concurrent use of other psychotropic medication can theoretically affect GFR and has not been excluded in our study. Such a relationship has not been confirmed in the literature. Moreover, because of the small number of patients in this study and patients being prescribed a number of other psychotropic medication for varying periods of time, it will be extremely difficult to assess their effect, if any, on the GFR. It is thus inferred that the chronic use of lithium without any indication of lithium toxicity (serum lithium levels within physiological range) in affective disorder has no significant effect on GFR. Further in cross-sectional studies, evaluating effects of Li-treatment on renal functions, age matching amongst the Li-patients and control subjects should be necessarily considered. ACKNOWLEDGEMENTS The authors are thankful to the Director, Postgraduate Institute of Medical Education and Research, Chandigarh, India for funding this project as a part of Institute's Intra-mural Research Scheme. Technical help rendered by Ms. Sangam Sood, Senior technician, PGIMER Research Cadre during the entire course of this work is greatly acknowledged. Thanks are also due to Mr. R.C. Goel, Bio statistician, PGIMER, Chandigarh for applying the appropriate statistical tests to the results of the study. REFERENCES APA (1987) Diagnostic and statistical manual of mental disorders. Edn.3rd, Washington DC : American Psychiatry Association. Boton.D.C, Gaviria.M. & Battle,D. (1987) Prevalence, pathogenesis and treatment of renal dysfunction associated with chronic lithium therapy. Am J Kidney Dis, 10, 329-345. Brown,P.W. & Legg.E.F. (1970) The estimation of lithium in serum. Ann Clin Biochem, 7, 13-17. Davison,A.M., Cameron,J.S., Granfeld, J.P., Kerr.D.M.S., Ritz,E. & Winerals,C.G. (1998) Lithium. In : Oxford Textbook of Clincial Nephrology, Vol.2, Edn.2nd, pp 1197-1201, Oxford University Press. Deodhar.S.D., Singh,B., Pathak.C.M., Sharan.P. & Kulhara,P.(1999) Thyroid functions in lithium treated psychiatric patients-a cross sectional study. Biol Trace Element Res, 67, 151-163. Hansen,H.E. & Amdisen,A. (1978) Lithium intoxication - a report of 23 cases and review of 100 cases from the literature. Q.J. Med, 47,123. Hestbech,J. Hansen,H.E., Amdisen,A. & Olsen.S. (1977) Chronic renal lesions following long term treatment with lithium. Kidney Int., 12, 205. Hetmar.O. & Rafaelsen.O.J. (1987) Lithium : long term effects on the kidney. IV Renal lithium clearance. Acta Psychiathca Scandinavica, 76, 2, 193-198. Jensen,P.W. & Rickers.H. (1984) Glomerular filtration rate during lithium therapy- a longitudinal study Acta Psychiathca Scandinavica, 70, 235. Kallner.G. & Petterson.U. (1995) Renal, thyroid and parathyroid fuction during lithium treatment: laboratory tests in 207 people treated for 1-30 years. Acta Psychiatr Scand, 91,48-51. Milier.P.D., Dubovsky.S.L., McDonald, K.M., Katz.F.H., Robertson.G.L. & Schrier, 413