BRITISH JOURNAL OF (2007), 190, 359^360. doi: 10.1192/bjp.bp.106.029868 SHORT REPORT AUTHOR’ S P ROOF

Lithium and risk for Alzheimer’s regression with backward selection of vari- ables was performed addressing variables in elderly patients with withwith PP550.10 in the univariate model. RESULTSRESULTS PAULA V. NUNES, ORESTES V. FORLENZA andandWAGNER F. GATTAZ From the total sample (nn¼118), 70 patients (59%) had normal cognitive function, 25 (21%) had mild cognitive impairment, and 23 (19%) had . Among those with dementia, 19 (16% of the total sam- ple) had Alzheimer’s disease and 4 had vas- cular dementia. The latter were excluded, Summary Bipolar disorder is diagnosis of bipolar disorder (American leaving 114 patients for further analysis. associated withincreased risk for Psychiatric Association, 1994); 60 years of Results of the cognitive assessment are age or more; continuous treatment for bi- available from the authors upon request. dementia.We compared the prevalence of polar disorder for at least the previous 6 Patients were allocated to two groups: Alzheimer’sdisease between 66 elderly months; and in the past month 66 patients (28 male, 38 female; mean age euthymic patients with bipolar disorder (scores on the Hamilton Rating Scale for 67.4 years, s.d.¼4.7) continuous treatment who were on chronic lithiumtherapy and (Hamilton, 1960), and the on for a mean of 71.2 months 48 similarsimilarpatientswithoutrecentlithium patients without recent lithium Young Rating Scale (Young et aletal,, (s.d.¼71.7); 48 patients (10 male, 38 female; 1978) of less than 8 and 5 respectively). mean age 69.1 years, s.d.¼4.6) treated with therapy.The prevalence of dementia in the Exclusion criteria were: electroconvulsive other -stabilising drugs for at least the whole sample was19% v. 7% inanage- therapy in the previous 6 months; acute past 6 months, 15 of whom had never re- comparable population. Alzheimer’s physical illness; organic brain ; ceived lithium and 33 who had received disease was diagnosedin 3 patients (5%) and with other major psychiatric lithium in the past (mean use of 54.1 syndromes. Informed consent was obtained months, s.d.¼55.4) but were off lithium on lithium and in16in 16 patients (33%) who from patients and a first-degree relative. for a mean of 59.4 months (s.d.¼55.7).55.7). were not on lithium (PP550.001).Ourcase^0.001).Our case^ Through hospital chart review we The prevalence of Alzheimer’s disease control data suggestthatlithiumtreatment detected 184 patients who fulfilled the first was 5% in the group on continuous lithium reduced the prevalence of Alzheimer’s three criteria. Twenty-seven patients could treatment (3 out of 66 patients) and 33% disease in patients with bipolar disorder to not be located, 10 had died and 12 refused (16 out of 48 patients) in the group without to participate; 17 patients were excluded recent lithium therapy (PP550.001). The pre- levels in the general elderly population. for not being euthymic or meeting exclu- valence of mild cognitive impairment was Thisisin accordance with reports that sion criteria. Thus, 118 patients with bi- 20% and 25% respectively (PP550.10). Cog-0.10).Cog- lithium inhibits crucial processes in the polar disorder (64%; 37 male, 81 female; nitive assessments of the 33 patients who pathogenesis of Alzheimer’sdisease. mean age 68.2 years, s.d.¼5) underwent had been treated with lithium in the past cognitive assessment with the Cambridge were: normal function, 14 patients (42%), Declaration of interest None.None. Examination for Mental Disorders of the mild cognitive impairment, 9 patients Funding detailed in Acknowledgements. Elderly (CAMDEX; Roth et aletal, 1986) and (27%), and Alzheimer’s disease, 10 patients the Informant Questionnaire on Cognitive (30%); this was very similar to assessments At therapeutic concentrations, lithium inhi- Decline in the Elderly (IQCODE; Jorm & of the remaining 15 patients in the group bits glycogen synthase kinase-3, a key Korten, 1988). Patients were classified, as who had never used lithium (40%, 20% enzyme in the metabolism of amyloid having normal cognitive function, mild cog- and 40% respectively, PP¼0.77).0.77). precursor protein and the phosphorylation nitive impairment (Petersen, 2004) and Within the group that had received con- of tau protein (Klein & Melton, 1996; DSM–IV dementia (American Psychiatric tinuous lithium therapy for the past 6months, LovestoneLovestone et aletal, 1999) which are critical Association, 1994) by assessors masked to there were no differences according to cog- steps in the formation of neuritic plaques treatment groups. The group with dementia nitive function in the mean daily dose and and neurofibrillary tangles, the pathologi- were further classified as Alzheimer’s dis- meanserum levels of lithium (0.81 (s.d.¼ cal hallmarks of Alzheimer’s disease. ease (McKhann et aletal, 1984) and vascular 0.18), 0.78 (s.d.¼0.17) and 0.69 (s.d.¼ Therefore, we examined whether exposure dementia (Roman et aletal, 1993).,1993). 0.15) mEq/l, PP¼0.50) throughout treatment. to chronic lithium treatment might protect Patients with Alzheimer’s disease were elderly patients with bipolar disorder Statistical analysis older (mean age 71.5 years, s.d.¼5.4) than5.4)than against Alzheimer’s disease. Parametric (Pearson’s ww22, Fisher’s exact test, those with mild cognitive impairment METHOD tt-test for two independent samples and with (mean age 67.2 years, s.d.¼4.0,4.0, PP¼0.006)0.006) one-way analysis of variance, corrected for and those with normal cognitive function Patients were recruited at the Institute of multiple comparisons by the Tukey test) (mean age 67.4 years, s.d.¼4.4,4.4, PP¼0.002).0.002). Psychiatry, University of SaSao˜o Paulo (which and, when indicated, non-parametric tests Consequently patients with Alzheimer’s dis- granted ethical approval for the study as a (Mann–Whitney test, Kruskal–Wallis test, ease also had a higher duration of bipolar whole) andSanta Casa Medical School, corrected for multiple comparisons by the disorder (disorder(PP¼0.015) and more previous Brazil. Inclusioncriteria were: a DSM–IV Dunn test) were used. A multinomial logistic depressive episodes (PP¼0.030) than those

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AUTHOR’SAUTHOR’ S PROOFP ROOF

with normal cognitive function. These differ- PAULAV.NUNES,PAULA V. NUNES, MD, PhD,ORESTESPhD, ORESTES V. FORLENZA, MD, PhD,WAGNER F.GATTAZ, MD, PhD, Laboratory of ences disappeared after correction for age. Neuroscience ^ LIM27, Department and Institute of Psychiatry, Faculty of Medicine,University of Sao Paulo, No other differences were found regarding Sao Paulo, Brazil the remaining socio-demographic and clini- cal variables. Significantly fewer patients CorrespCorrespondence:Professorondence:Professor WaWagnergner F.Gattaz, Department & Institute of Psychiatry,Faculty of Medicine, with Alzheimer’s disease had received recent University of Sao Paulo, Sao Paulo,Brazil. Email: gattaz@@usp.br continuous lithium treatment compared with (First received 14 August 2006, final version 22 November 2006, accepted 8 January 2007) those with mild cognitive impairment or nor- mal cognitive function (PP550.001). The use reducing the lifetime number of affective re- Alzira Denise Herzog da Silva) and FAPESP (Fundac(Fundacao a‹o of , , antipsy- lapses. This, however, does not hold true in do Amparo a' Pesquisa do Estado de So Paulo, project chotics, , and other our sample, because the differences between 02/13633-7). P.V.N. was supported by CAPES (Coor- denacdenacao a‹o de de Aperfeicoamento Aperfeicoamento de Pessoal de N|N|vel¤vel did not differ with cognitive the lithium and the non-lithium groups re- Superior).Superior). function (data available on request). garding the number of previous depressive Logistic regression revealed that only the and manic episodes were not significant (de- REFERENCES influences of age (PP550.01) and lithium use pression: 10.4 (s.d.¼10.3) and 13.9 (s.d.¼ 55 ((PP 0.001) on cognitive outcomes remained 13.1) respectively, PP¼0.436; mania: 7.8 American Psychiatric Association (1994) Diagnostic significant. After controlling for age, lithium (s.d.¼8.9) and 11.7 (s.d.¼12.9) respectively, and Statistical Manual of Mental Disorders (4th edn)edn)(4th (DSM^IV). APA. use remained associated with a smaller risk PP¼0.253). of Alzheimer’s disease (OR¼0.079; 95% CI Folstein, M. F., Folstein, S. E. & McHugh, P.R. (1975) There are reports of negative effects of ‘Mini-mental state’. A practical method for grading the 55 0.020–0.321, PP 0.001). short-term lithium therapy on cognitive state of patients for the clinician. Journal of When we excluded patients with Alz- (for a review see Pachet & Wisniewski, Psychiatric Research,, 12,189^198.,189^198. heimer’s disease from the analysis, no nega- 2003). One could argue that psychiatrists, Hamilton, M. (1960)(196 0) Rating scale for depression. JournalJournal of Neurology, Neurosurgery, and Psychiatry,, 23, 56^62.,56^62. tive effects of long-term lithium treatment aware of these possible negative effects, on cognition were observed, as no differ- Herrera, E.,Caramelli, P., Silveira, A. S., et aletal (2002) would avoid prescribing lithium to patients Epidemiologic survey of dementia in a community- ences were found between the lithium and with dementia and this could explain the dwelling Brazilian population. Alzheimer Disease and the comparison groups in the extensive increased prevalence of Alzheimer’s disease Associated Disorders,, 1616,103^108. assessment of their neuropsychological in our comparison group. However, this is Jorm, A. F. & Korten, A. E. (1988) Assessment of performance (data available on request). cognitive decline in the elderly by informant interview. unlikely because most of our patients had British Journal of Psychiatry,, 152,,209^213. 209^213. previously undiagnosed and mild Alzhei- DISCUSSION Kessing, L.V. & Nilsson, F. M. (2003) Increased risk of mer’s disease (mean Mini-Mental State developing dementia in patients with major affective Examination score 21; Folstein et aletal,, disorders compared to patients with other medical In the present cross-sectional study of elderly illnesses. Journal of Affective Disorders,, 7373, 261^269. 1975). Moreover, the mean duration of bi- patients with bipolar disorder, the prevalence Klein, P. S. & Melton, D. A. (1996) Amolecular polar disorder in our sample was more than of dementia was 19%, which is almost three mechanism for the effect of lithium on development. 25 years. Even our patients with cognitive Proceedings of the National Academy of Sciences of the times that expected in the elderly Brazilian impairment who were taking lithium had of America,, 93,8455^8459. population (7%; Herrera et aletal, 2002). This taken it continuously for the past 6 years. Lovestone, S., Davis, D. R.,Webster,M.T.,R.,Webster, M.T., et aletal (1999)(1999) prevalence is similar to that in other studies Lithium reduces tau phosphorylation: effects in living We feel therefore that the decision to pre- which report an increased risk for dementia cells and in neurons at therapeutic concentrations. scribe lithium was based on the clinical re- ,, 4545,995^1003. in patients with affective disorders and that sponse and thus was independent of the McKhann, G., Drachman, D., Folstein, M., et aletal this risk increases with the number and dura- cognitive status of our patients, and an aa (19 8 4) Clinical diagnosis of Alzheimer’s disease: report tion of previous affective episodes (Kessing prioripriori selection seems unlikely. of the NINCDS-ADRDA Work Group under the auspices & Nilsson, 2003; Thompson et al, 2005).2005). of Department of and Human ServicesTask Force It thus seems possible that a protective In our study, only patients in the group on Alzheimer’s Disease. NeurologyNeurology,, 3434, 939^944.,939^944. effect of lithium against Alzheimer’s disease without recent continuous lithium treat- Pachet, A. K. & Wisniewski, A. M. (2003) TheThe in patients with bipolar disorder might be a effects of lithium on cognition: an updated review. ment showed an increased prevalence of result of its intrinsic biological properties in Psychopharmacology,, 170170, 225^234. Alzheimer’s disease (33%) and a trend to- the brain. Preliminary data from our Petersen, R. C. (2004) Mild cognitive impairment as a ward increased mild cognitive impairment, diagnostic entity. Journal of Internal Medicine,, 256256,183^194. laboratory indicate that lithium inhibits which is a risk factor for Alzheimer’s dis- Roman, G. C.Tatemichi,T.C. Tatemichi,T. K., Erkinjuntti,Erkinjuntti,T., T., et aletal the transcription of the glycogen synthase ease (Petersen, 2004). Conversely, the pre- (19 93) : diagnostic criteria for kinase-3 gene. Through this pathway research studies. Report of the NINDS^AIREN valence of Alzheimer’s disease in the lithium may inhibit crucial processes in International Workshop. Neurology,, 4343,,250^260. 250^260. lithium group (5%) was similar to that the pathogenesis of disease, such as the Roth, M., Tym, E., Mountjoy, C. Q., et aletal (19 8 6) reported in the elderly general population CAMDEX. A standardised instrument for the diagnosis overproduction of amyloid-bb and tau hyper- in Brazil. These findings suggest that of in the elderly with special reference phosphorylation (Klein & Melton, 1996). to the early detection of dementia. British Journal of lithium treatment might reduce the risk of PsychiatryPsychiatry,, 149149, 698^709.,698^709. dementia in patients with bipolar disorder. ACKNOWLEDGEMENTS Thompson, J. M., Gallagher, P., Hughes, J. H., et aletal The mechanisms by which lithium might (2005) Neurocognitive impairment in euthymic patients WethankStevinZungandPriscillaWackerforhelpinWe thank Stevin Zung and Priscilla Wacker for help in exert this effect need clarification. Because with bipolar affective disorder. British Journal of data collection and Valentim Gentil, MD, PhD, for PsychiatryPsychiatry,, 186186,,32^40. 32^40. the risk for dementia may increase with comments on a previous draft of this work. The Young, R. C., Biggs, J.T., Ziegler,V.Ziegler,V.E., E., et aletal (1978)(19 78) AA the number of previous affective episodes, Laboratory of Neuroscience ^ LIM27 receives finan- rating scale for mania: reliability, validity and sensitivity. lithium might protect against dementia by cial support from ABADHS (Associac(AssociacaooBeneficente a‹ Beneficente British Journal of Psychiatry,, 133, 429^435.,429^435.

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