Mood stabilizers in Alzheimer's disease: symptomatic and neuroprotective rationales

Insights into Structural Modifications of Valproic Acid and Their Pharmacological Profile

Valproic acid (VPA) is a well-established anticonvulsant drug discovered serendipitously and marketed for the treatment of epilepsy, migraine, bipolar disorder and neuropathic pain. Apart from this, VPA has potential therapeutic applications in other central nervous system (CNS) disorders and in various cancer types. Since the discovery of its anticonvulsant activity, substantial efforts have been made to develop structural analogues and derivatives in an attempt to increase potency and decrease adverse side effects, the most significant being teratogenicity and hepatotoxicity. Most of these compounds have shown reduced toxicity with improved potency. The simple structure of VPA offers a great advantage to its modification. This review briefly discusses the pharmacology and molecular targets of VPA. The article then elaborates on the structural modifications in VPA including amide-derivatives, acid and cyclic analogues, urea derivatives and pro-drugs, and compares their pharmacological profile with that of the parent molecule. The current challenges for the clinical use of these derivatives are also discussed. The review is expected to provide necessary knowledgebase for the further development of VPA-derived compounds.

Agitation and impulsivity in mid and late life as possible risk markers for incident dementia

To identify knowledge gaps regarding new-onset agitation and impulsivity prior to onset of cognitive impairment or dementia the International Society to Advance Alzheimer's Research and Treatment Neuropsychiatric Syndromes (NPS) Professional Interest Area conducted a scoping review. Extending a series of reviews exploring the pre-dementia risk syndrome Mild Behavioral Impairment (MBI), we focused on late-onset agitation and impulsivity (the MBI impulse dyscontrol domain) and risk of incident cognitive decline and dementia. This scoping review of agitation and impulsivity pre-dementia syndromes summarizes the current biomedical literature in terms of epidemiology, diagnosis and measurement, neurobiology, neuroimaging, biomarkers, course and prognosis, treatment, and ongoing clinical trials. Validations for pre-dementia scales such as the MBI Checklist, and incorporation into longitudinal and intervention trials, are needed to better understand impulse dyscontrol as a risk factor for mild cognitive impairment and dementia.

Differential Expression of Multiple Disease-Related Protein Groups Induced by Valproic Acid in Human SH-SY5Y Neuroblastoma Cells

Valproic acid (VPA) is a multifunctional medication used for the treatment of epilepsy, mania associated with bipolar disorder, and migraine. The pharmacological effects of VPA involve a variety of neurotransmitter and cell signaling systems, but the molecular mechanisms underlying its clinical efficacy is to date largely unknown. In this study, we used the isobaric tags for relative and absolute quantitation shotgun proteomic analysis to screen differentially expressed proteins in VPA-treated SH-SY5Y cells. We identified changes in the expression levels of multiple proteins involved in Alzheimer’s disease, Parkinson’s disease, chromatin remodeling, controlling gene expression via the vitamin D receptor, ribosome biogenesis, ubiquitin-mediated proteolysis, and the mitochondrial oxidative phosphorylation and electron transport chain. Our data indicate that VPA may modulate the differential expression of proteins involved in mitochondrial function and vitamin D receptor-mediated chromatin transcriptional regulation and proteins implicated in the pathogenesis of neurodegenerative diseases.

Bioinformatic Analysis Reveals Phosphodiesterase 4D-Interacting Protein as a Key Frontal Cortex Dementia Switch Gene

The mechanisms that initiate dementia are poorly understood and there are currently no treatments that can slow their progression. The identification of key genes and molecular pathways that may trigger dementia should help reveal potential therapeutic reagents. In this study, SWItch Miner software was used to identify phosphodiesterase 4D-interacting protein as a key factor that may lead to the development of Alzheimer’s disease, vascular dementia, and frontotemporal dementia. Inflammation, PI3K-AKT, and ubiquitin-mediated proteolysis were identified as the main pathways that are dysregulated in these dementias. All of these dementias are regulated by 12 shared transcription factors. Protein–chemical interaction network analysis of dementia switch genes revealed that valproic acid may be neuroprotective for these dementias. Collectively, we identified shared and unique dysregulated gene expression, pathways and regulatory factors among dementias. New key mechanisms that lead to the development of dementia were revealed and it is expected that these data will advance personalized medicine for patients.

Evaluation of a human neural stem cell culture method for prediction of the neurotoxicity of anti-epileptics

Human neural stem cells have been proposed as an in vitro model to predict neurotoxicity. In this study, the potential of in vitro cultures of human-derived neurospheres to predict the effects of various anti-epileptic drugs (sodium valproate, phenytoin, carbamazepine and phenobarbitone) was evaluated. In general, these drugs had no significant effects on cell viability, total cellular protein, and neuronal process length at low doses, but at high doses these parameters were reduced significantly. Therapeutic doses of sodium valproate and phenytoin had a clear effect on neurosphere size and cell migration, with a significant reduction in both parameters when compared with the control group. The other drugs (carbamazepine and phenobarbitone) reduced neurosphere size and cell migration only at higher doses. The expression levels of glial fibrillary protein and tubulin III, which were used to identify astrocytes and neuronal cells, respectively, were reduced in a dose-dependent manner that became significant at high doses. The levels of glial fibrillary protein did not indicate any occurrence of reactive astrocytosis.

Design of a Bayesian adaptive phase 2 proof-of-concept trial for BAN2401, a putative disease-modifying monoclonal antibody for the treatment of Alzheimer's disease

Introduction

Recent failures in phase 3 clinical trials in Alzheimer's disease (AD) suggest that novel approaches to drug development are urgently needed. Phase 3 risk can be mitigated by ensuring that clinical efficacy is established before initiating confirmatory trials, but traditional phase 2 trials in AD can be lengthy and costly.

Methods

We designed a Bayesian adaptive phase 2, proof-of-concept trial with a clinical endpoint to evaluate BAN2401, a monoclonal antibody targeting amyloid protofibrils. The study design used dose response and longitudinal modeling. Simulations were used to refine study design features to achieve optimal operating characteristics.

Results

The study design includes five active treatment arms plus placebo, a clinical outcome, 12-month primary endpoint, and a maximum sample size of 800. The average overall probability of success is ≥80% when at least one dose shows a treatment effect that would be considered clinically meaningful. Using frequent interim analyses, the randomization ratios are adapted based on the clinical endpoint, and the trial can be stopped for success or futility before full enrollment.

Discussion

Bayesian statistics can enhance the efficiency of analyzing the study data. The adaptive randomization generates more data on doses that appear to be more efficacious, which can improve dose selection for phase 3. The interim analyses permit stopping as soon as a predefined signal is detected, which can accelerate decision making. Both features can reduce the size and duration of the trial. This study design can mitigate some of the risks associated with advancing to phase 3 in the absence of data demonstrating clinical efficacy. Limitations to the approach are discussed.

Effects of lithium and valproic acid on BDNF protein and gene expression in an in vitro human neuron-like model of degeneration

One of the common effects of lithium (Li) and valproic acid (VPA) is their ability to protect against excitotoxic insults. Neurodegenerative and neuropsychiatric diseases may be also associated with altered trophic support of brain-derived neurotrophic factor (BDNF), the most widely distributed neurotrophin in the central nervous system. However, despite these evidences, the effect of Li-VPA combination on BDNF after excitoxic insult has been inadequately investigated. We address this issue by exposing a human neuroblastoma cell line (SH-SY5Y) to neurotoxic concentration of L-glutamate and exploring whether the neuroprotective action of Li-VPA on these cells is associated with changes in BDNF protein and mRNA levels. The results showed that pre-incubation of Li-VPA abolished the toxic effect of glutamate on SH-SY5Y cell survival and this neuroprotective effect was associated with increased synthesis and mRNA expression of BDNF after 24 and 48 h of incubation. In conclusion, this study demonstrates that the neuroprotective effects of Li-VPA against glutamate-induced neurotoxicity in SH-SY5Y neuroblastoma cells is associated with increased synthesis and mRNA expression of BDNF. These data further support the idea that these two drugs can be used for prevention and/or treatment of glutamate-related neurodegenerative disorders.

3',4'-Dimethoxyflavone and valproic acid promotes the proliferation of human hematopoietic stem cells

INTRODUCTION

Human hematopoietic stem cells (HSCs) have been clinically used for transplantation and gene and cellular therapy for more than 4 decades. However, this use is limited because of the challenges in the ex vivo culturing of HSCs. The major hurdle is to amplify these cells without losing their self-renewing property.

METHODS

In our study, we tested 3',4'-dimethoxyflavone (3'4'-DMF) and valproic acid (VPA) on the ex vivo expansion of HSCs under both normoxic (20% O2) and hypoxic (1% O2) conditions. 3'4'-DMF is a widely used anticancer drug that acts as a competitive antagonist of the aryl hydrocarbon receptor. VPA is a potent inhibitor of histone deacetylase and is used in the treatment of neurologic disorders.

RESULTS

Culturing HSCs (from mobilized peripheral blood) under normoxia, with 3'4'-DMF and VPA, highly preserved the CD34 positivity (3'4'-DMF, 22.1%, VPA, 20.3%) after 1 week and strongly enhanced the CD34(+) cells (3'4'-DMF, 27.8 fold; VPA, 34.1 fold) compared with the control cultures (11.6% and 14.4 fold). Addition of 3'4'-DMF and VPA also resulted in more primary colonies and replating efficiency compared with control cultures. Although no significant effect was observed on the enhancement of CD34(+) cells under hypoxia, the number of primary colonies was significantly higher than the control cultures.

CONCLUSIONS

Based on these findings, this study presents, for the first time, in vitro evidence for a new and relevant effect of 3'4'-DMF on human HSCs. In addition, the results suggest a potential clinical use of 3'4'-DMF and VPA in HSC therapy.

Gabapentin is neuroprotective through glutamate receptor-independent mechanisms in staurosporine-induced apoptosis of cultured rat cerebellar neurons

The anticonvulsants that are currently available modulate the activity of neuronal receptors and ion channels, which are equally involved in apoptotic pathways. We investigated the hypothesis that gabapentin (GP), an anticonvulsant without effect on glutamate receptors acting as GABA analog, has neuroprotective properties. For comparison, we chose topiramate (TPM), which has been reported to be neuroprotective via AMPA receptors blockade. For this purpose, we used rat cerebellar granule neuron (CGN) cultures and we triggered apoptosis independent of glutamate receptors with staurosporine, a broad-spectrum protein kinase inhibitor. GP at therapeutic range concentration significantly increased cell viability in CGN cultures maintained in physiological KCl concentration and reversed apoptosis induced by staurosporine. Blockade of NMDA or AMPA receptors by MK801 or NBQX, respectively, did not alter GP neuroprotection, which was reversed instead by GABA. In contrast, protective effect of TPM on STS-treated CGN cultures was annihilated by NBQX, and not altered by MK801 or GABA. Treatments with neuroprotective concentrations of GP or TPM did not modify the expression of neuronal cell adhesion molecule or synaptophysin or the morphological aspect of neuronal endings. In summary, we report that GP is neuroprotective through glutamate-receptor independent mechanisms and without alteration of neuronal plasticity markers, which makes it a possible candidate for clinical neuroprotection trials.

Lithium and valproate prevent olfactory discrimination and short-term memory impairments in the intranasal 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) rat model of Parkinson's disease

We have recently demonstrated that rodents treated intranasally with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) display time-dependent impairments in olfactory, emotional, cognitive and motor functions associated with disruption of dopaminergic neurotransmission in different brain structures conceivably analogous to those observed during different stages of Parkinson's disease (PD). On the other hand, lithium (Li) and valproate (VPA) are two primary drugs used to treat bipolar mood disorder that have recently emerged as promising neuroprotective agents. The present data indicates that the pretreatment with Li (47.5 mg/kg) or VPA (200 mg/kg) by intraperitoneal route during 7 consecutive days was able to prevent olfactory discrimination and short-term memory impairments evaluated in the social recognition and step-down inhibitory avoidance tasks in rats infused with a single intranasal (i.n.) administration of MPTP (0.1 mg/nostril). Despite the absence of clear depressive-like responses following the current MPTP dose, Li and VPA treatment presented an antidepressant profile reducing the immobility time in the forced swimming test. Importantly, at this time no significant alterations on the locomotor activity of the animals were observed in the open field test. Moreover, Li and VPA prevented dopamine depletion in the olfactory bulb and striatum of MPTP-infused rats. These results provide new insights in experimental models of PD, indicating that Li and VPA may represent new therapeutic tools for the management of olfactory and cognitive symptoms associated to early preclinical phases of PD, together with their neuroprotective potential demonstrated in previous research.

Risk of mortality among individual antipsychotics in patients with dementia

OBJECTIVE

The use of antipsychotics to treat the behavioral symptoms of dementia is associated with greater mortality. The authors examined the mortality risk of individual agents to augment the limited information on individual antipsychotic risk.

METHOD

The authors conducted a retrospective cohort study using national data from the U.S. Department of Veterans Affairs (fiscal years 1999-2008) for dementia patients age 65 and older who began outpatient treatment with an antipsychotic (risperidone, olanzapine, quetiapine, or haloperidol) or valproic acid and its derivatives (as a nonantipsychotic comparison). The total sample included 33,604 patients, and individual drug groups were compared for 180-day mortality rates. The authors analyzed the data using multivariate models and propensity adjustments.

RESULTS

In covariate-adjusted intent-to-treat analyses, haloperidol was associated with the highest mortality rates (relative risk=1.54, 95% confidence interval [CI]=1.38-1.73) followed by risperidone (reference), olanzapine (relative risk=0.99, 95% CI=0.89-1.10), valproic acid and its derivatives (relative risk=0.91, 95% CI=0.78-1.06), and quetiapine (relative risk=0.73, 95% CI=0.67-0.80). Propensity-stratified and propensity-weighted models as well as analyses controlling for site of care and medication dosage revealed similar patterns. The mortality risk with haloperidol was highest in the first 30 days but decreased significantly and sharply thereafter. Among the other agents, mortality risk differences were most significant in the first 120 days and declined in the subsequent 60 days during follow-up.

CONCLUSIONS

There may be differences in mortality risks among individual antipsychotic agents used for treating patients with dementia. The use of valproic acid and its derivatives as alternative agents to address the neuropsychiatric symptoms of dementia may carry associated risks as well.

Chronic divalproex sodium to attenuate agitation and clinical progression of Alzheimer disease

CONTEXT

Agitation and psychosis are common in Alzheimer disease and cause considerable morbidity. We attempted to delay or to prevent agitation and psychosis with the use of divalproex sodium (valproate).

OBJECTIVE

To determine whether treatment with valproate could delay or prevent emergence of agitation or psychosis.

DESIGN, SETTING, AND PATIENTS

A multicenter, randomized, double-blind, placebo-controlled trial of flexible-dose valproate in 313 (of 513 screened) individuals with moderate Alzheimer disease who had not yet experienced agitation or psychosis. The study was conducted from November 1, 2005, through March 31, 2009, at 46 sites in the United States.

INTERVENTION

Participants were randomly assigned to valproate treatment at a target dose of 10 to 12 mg per kilogram of body weight per day or identical-appearing placebo for 24 months followed by a 2-month period of single-blind placebo treatment.

MAIN OUTCOME MEASURE

Time to emergence of clinically significant agitation or psychosis.

RESULTS

A total of 122 participants (59 receiving valproate and 63 receiving placebo) completed 24 months of treatment while taking study medication; 42 (27 receiving valproate and 15 receiving placebo) reached 24 months having discontinued study medication; 150 reached month 26. There was no difference between groups in time to emergence of agitation or psychosis (Cox proportional hazard ratio, 0.96; P = .88). There was no difference between groups in change on any secondary outcome. The valproate group had higher rates of somnolence, gait disturbance, tremor, diarrhea, and weakness. Eighty-eight participants underwent magnetic resonance imaging scans at baseline and 12 months; the valproate group showed greater loss in hippocampal and whole-brain volume, accompanied by greater ventricular expansion (P < .001).

CONCLUSION

Valproate treatment did not delay emergence of agitation or psychosis or slow cognitive or functional decline in patients with moderate Alzheimer disease and was associated with significant toxic effects.

Chronic divalproex sodium use and brain atrophy in Alzheimer disease

OBJECTIVE

We evaluated the effect of the divalproex sodium formulation of valproic acid on brain volumes using MRI in people with mild to moderate Alzheimer disease (AD) and assessed for changes associated with behavioral and cognitive effects.

METHODS

Eighty-nine of 313 participants randomized to divalproex or placebo in a 24-month, parallel-group trial received MRI scans at baseline and 12 months. Interval MRI annual percent changes in whole brain, ventricular, and hippocampal volumes were the primary outcomes of interest. Change from baseline in clinical outcomes was assessed at 6-month intervals.

RESULTS

There were no baseline differences between active treatment and placebo groups in age, education, brain volumes, clinical rating scores, or APOE ε4 carrier status. The group treated with divalproex showed a greater rate of decline in left and right hippocampal and brain volumes (-10.9% and -12.4% vs -5.6% and -6.3%, and -3.5% vs -1.4%, respectively), and a greater rate of ventricular expansion (24.5% vs 9.9%) (p < 0.001). Mini-Mental State Examination scores showed a more rapid decline with divalproex through month 12 (placebo = -2.0 ± 4.3, divalproex = -3.9 ± 4.0) (p = 0.037), although there were no changes on other cognitive, behavioral, or functional ratings at 12 and 24 months.

CONCLUSIONS

Divalproex treatment was associated with accelerated brain volume loss over 1 year and perhaps with greater cognitive impairment. The long-term clinical effects of these changes are not known.

The embryonic stem cell test as tool to assess structure-dependent teratogenicity: the case of valproic acid

Teratogenicity can be predicted in vitro using the embryonic stem cell test (EST). The EST, which is based on the morphometric measurement of cardiomyocyte differentiation and cytotoxicity parameters, represents a scientifically validated method for the detection and classification of chemicals according to their teratogenic potency. Furthermore, an abbreviated protocol applying flow cytometry of intracellular marker proteins to determine differentiation into the cardiomyocyte lineage is available. Although valproic acid (VPA) is in worldwide clinical use as antiepileptic drug, it exhibits two severe side effects, i.e., teratogenicity and hepatotoxicity. These limitations have led to extensive research into derivatives of VPA. Here we chose VPA as model compound to test the applicability domain and to further evaluate the reliability of the EST. To this end, we study six closely related congeners of VPA and demonstrate that both the standard and the molecular flow cytometry-based EST are well suited to indicate differences in the teratogenic potency among VPA analogs that differ only in chirality or side chain length. Our data show that identical results can be obtained by using the standard EST or a shortened protocol based on flow cytometry of intracellular marker proteins. Both in vitro protocols enable to reliably determine differentiation of murine stem cells toward the cardiomyocyte lineage and to assess its chemical-mediated inhibition.

A meta-analysis of mood stabilizers for Alzheimer's disease

The objective of this study was to assess the clinical evidence for or against mood stabilizers as a treatment for Alzheimer's disease (AD). We searched 5 databases from their inception to January 2010. Five randomized clinical trials of mood stabilizers to treat human patients suffering from AD were included. These trials assessed the effectiveness of mood stabilizers as an adjunct treatment to conventional anti-dementia drugs on behavioral and psychological symptoms, especially on agitation. Methodological quality was assessed using the Jadad score. The results suggested a significant effect in favor of placebo on the Mini-Mental Status Examination [n=270, weight mean difference (WMD), -0.89; 95% confidence intervals (CIs) -1.69 to -0.09, P=0.03] and on the Neuropsychiatric Inventory total (NPI total) (n=51, WMD, 3.71; 95% CIs 0.15 to 7.26, P=0.04). There were no significant differences in change scores on total Brief Psychiatric Rating Scale (BPRS total), NPI/BPRS agitation, Cohen-Mansfield Agitation Inventory total and Physical Self Maintenance Scale between mood stabilizers and placebo. Only one of these studies was free of methodological limitations (Jadad score=5). In conclusion, based on the existing evidence, mood stabilizers are ineffective or even harmful as a treatment for AD.

Does lithium protect against dementia?

OBJECTIVE

To investigate whether treatment with lithium in patients with mania or bipolar disorder is associated with a decreased rate of subsequent dementia.

METHODS

Linkage of register data on prescribed lithium in all patients discharged from psychiatric health care service with a diagnosis of mania or bipolar disorder and subsequent diagnoses of dementia in Denmark during a period from 1995 to 2005.

RESULTS

A total of 4,856 patients with a diagnosis of a manic or mixed episode or bipolar disorder at their first psychiatric contact were included in the study. Among these patients, 2,449 were exposed to lithium (50.4%), 1,781 to anticonvulsants (36.7%), 4,280 to antidepressants (88.1%), and 3,901 to antipsychotics (80.3%) during the study period. A total of 216 patients received a diagnosis of dementia during follow-up (103.6/10,000 person-years). During the period following the second prescription of lithium, the rate of dementia was decreased compared to the period following the first prescription. In contrast, the rates of dementia during multiple prescription periods with anticonvulsants, antidepressants, or antipsychotics, respectively, were not significantly decreased compared to the rate of dementia during the period with one prescription of these drugs.

CONCLUSIONS

Continued treatment with lithium was associated with a reduced rate of dementia in patients with bipolar disorder in contrast to continued treatment with anticonvulsants, antidepressants, or antipsychotics. Methodological reasons for these findings cannot be excluded due to the nonrandomized nature of the data.

Structure-function studies for the panacea, valproic acid

The anticonvulsant properties of VPA (valproic acid), a branched short-chain fatty acid, were serendipitously discovered in 1963. Since then, therapeutic roles of VPA have increased to include bipolar disorder and migraine prophylaxis, and have more recently been proposed in cancer, Alzheimer's disease and HIV treatment. These numerous therapeutic roles elevate VPA to near 'panacea' level. Surprisingly, the mechanisms of action of VPA in the treatment of many of these disorders remain unclear, although it has been shown to alter a wide variety of signalling pathways and a small number of direct targets. To analyse the mechanism of action of VPA, a number of studies have defined the structural characteristics of VPA-related compounds giving rise to distinct therapeutic and cellular effects, including adverse effects such as teratogenicity and hepatotoxicity. These studies raise the possibility of identifying target-specific novel compounds, providing better therapeutic action or reduced side effects. This short review will describe potential therapeutic pathways targeted by VPA, and highlight studies showing structural constraints necessary for these effects.

Management of agitation and aggression associated with Alzheimer disease

Agitation and aggression are frequently occurring and distressing behavioral and psychological symptoms of dementia (BPSD). These symptoms are disturbing for individuals with Alzheimer disease, commonly confer risk to the patient and others, and present a major management challenge for clinicians. The most widely prescribed pharmacological treatments for these symptoms-atypical antipsychotics-have a modest but significant beneficial effect in the short-term treatment (over 6-12 weeks) of aggression but limited benefits in longer term therapy. Benefits are less well established for other symptoms of agitation. In addition, concerns are growing over the potential for serious adverse outcomes with these treatments, including stroke and death. A detailed consideration of other pharmacological and nonpharmacological approaches to agitation and aggression in patients with Alzheimer disease is, therefore, imperative. This article reviews the increasing evidence in support of psychological interventions or alternative therapies (such as aromatherapy) as a first-line management strategy for agitation, as well as the potential pharmacological alternatives to atypical antipsychotics-preliminary evidence for memantine, carbamazepine, and citalopram is encouraging.

Paliperidone as a mood stabilizer: a pre-frontal cortex synaptoneurosomal proteomics comparison with lithium and valproic acid after chronic treatment reveals similarities in protein expression

A series of recent studies has demonstrated that the molecules involved in regulation of neuronal plasticity are also involved in the mode of action of antidepressants and mood stabilizer drugs. Intracellular calcium signaling, energy metabolism, and neuronal plasticity can be influenced by inducing axonal remodeling and increasing levels of certain synaptic proteins. Because antipsychotic drugs are used as mood stabilizers our studies focused on a newly-marketed antipsychotic drug, paliperidone. We determined changes in rat synaptoneurosomal proteins after chronic treatment with paliperidone, lithium salt, or valproic acid in order to find similarities or differences between the mode of action of paliperidone and these two classical mood stabilizers. We determined differential protein expression profiles in prefrontal cortex (PFC) of male Sprague-Dawley rats (n = 4/group). Synaptoneurosomal-enriched preparations were obtained from PFC after chronic treatment with these three drugs. Proteins were separated by 2D-DIGE and identified by nano-LC-MS/MS. We observed similar protein expression profiles at the synaptoneurosomal level, suggesting that the mode of action for paliperidone is similar to that of lithium and valproic acid. However, the expression profile for paliperidone was more similar to that of lithium. Pathways affected in common by these two drugs included oxidative phosphorylation, electron transport, carbohydrate metabolism, and post-synaptic cytokinesis implicating the effects of these drugs in signaling pathways, energy metabolism, and synaptic plasticity.

Synergistic neuroprotective effects of lithium and valproic acid or other histone deacetylase inhibitors in neurons: roles of glycogen synthase kinase-3 inhibition

Lithium and valproic acid (VPA) are two primary drugs used to treat bipolar mood disorder and have frequently been used in combination to treat bipolar patients resistant to monotherapy with either drug. Lithium, a glycogen synthase kinase-3 (GSK-3) inhibitor, and VPA, a histone deacetylase (HDAC) inhibitor, have neuroprotective effects. The present study was undertaken to demonstrate synergistic neuroprotective effects when both drugs were coadministered. Pretreatment of aging cerebellar granule cells with lithium or VPA alone provided little or no neuroprotection against glutamate-induced cell death. However, copresence of both drugs resulted in complete blockade of glutamate excitotoxicity. Combined treatment with lithium and VPA potentiated serine phosphorylation of GSK-3 alpha and beta isoforms and inhibition of GSK-3 enzyme activity. Transfection with GSK-3alpha small interfering RNA (siRNA) and/or GSK-3beta siRNA mimicked the ability of lithium to induce synergistic protection with VPA. HDAC1 siRNA or other HDAC inhibitors (phenylbutyrate, sodium butyrate or trichostatin A) also caused synergistic neuroprotection together with lithium. Moreover, combination of lithium and HDAC inhibitors potentiated beta-catenin-dependent, Lef/Tcf-mediated transcriptional activity. An additive increase in GSK-3 serine phosphorylation was also observed in mice chronically treated with lithium and VPA. Together, for the first time, our results demonstrate synergistic neuroprotective effects of lithium and HDAC inhibitors and suggest that GSK-3 inhibition is a likely molecular target for the synergistic neuroprotection. Our results may have implications for the combined use of lithium and VPA in treating bipolar disorder. Additionally, combined use of both drugs may be warranted for clinical trials to treat glutamate-related neurodegenerative diseases.

A case series on the hypothesized connection between dementia and bipolar spectrum disorders: bipolar type VI?

BACKGROUND

The concept of bipolar spectrum disorders has opened therapeutic opportunities for patients with atypical and complex affective conditions. The literature has recently described several commonalities in pathophysiological processes of bipolar disorders and dementia. However, this connection has been insufficiently appreciated at the clinical level, in part because affective dysregulation in the elderly and, particularly in the dementia setting, is typically attributed either to secondary depressive states or otherwise relegated to a neurologically understandable behavioral complication resulting from cerebral disease.

METHODS

We selected a case series of 10 elderly patients with late-onset mood and related behavioral symptomatology and cognitive decline without past history of clear-cut bipolar disorder. Clinical features, temperament, cognition, family history and pharmacological response were assessed to identify prototypical patients to illustrate the complexities of the dementia-bipolar interface.

RESULTS

Mixed and depressive mood symptoms were most commonly observed and all patients had been premorbidly of hyperthymic, cyclothymic and/or irritable temperaments. Most patients had a family history of bipolar disorder or disorders related to the bipolar diathesis. Symptoms were often refractory to or aggravated by antidepressants and acetylcholinesterase inhibitors, whereas mood stabilizers and/or atypical antipsychotics were beneficial, promoting behavioral improvement in all treated patients and marked cognitive recovery in five.

LIMITATIONS

Case series with retrospective methodology.

CONCLUSION AND CLINICAL IMPLICATIONS

Patients with cognitive decline and frequent mood lability might be manifesting a late-onset bipolar spectrum disorder, which we posit as type VI. We further posit that dementia and/or other biopsychosocial challenges associated with aging might release latent bipolarity in such individuals. Antidepressants, even drugs targeting dementia, might aggravate the behavioral dysregulation in these patients. Evaluation of premorbid temperament and/or family history of bipolarity and related disorders might help in broadening the clinical and biological understanding of such patients, providing a rationale for better customized treatment along the lines of mood stabilization and avoidance of antidepressants.

Neurobehavioral sequelae of traumatic brain injury: evaluation and management

Traumatic brain injury (TBI) is a worldwide public health problem. Over the last several decades, improvements in acute care have resulted in higher survival rates. Unfortunately, the majority of survivors of moderate and severe TBI have chronic neurobehavioral sequelae, including cognitive deficits, changes in personality and increased rates of psychiatric illness. These neurobehavioral problems are understandable in the context of the typical profile of regional brain damage associated with trauma. This paper presents an overview of the neurobehavioral sequelae of TBI and outlines issues to consider in the evaluation and management of these challenges.

[Anticonvulsant mood stabilizers in the treatment of behavioral and psychological symptoms of dementia (BPSD)]

INTRODUCTION

Dementia, besides the dominant cognitive disorders that define it, is associated with behavioral disturbances, the consequences of which are, on various levels, a determining factor for the handling of these patients. The treatment of behavioral and psychological symptoms is essential and although, to date, no therapeutic solution is satisfactory, it is necessary to look for an alternative to the neuroleptics usually employed, which raise real problems of tolerance in this geriatric population.

BACKGROUND

For several years, anticonvulsants, among which some have shown mood stabilizing activity, have been the object of research in this indication. The purpose of this review of the literature is to assess the interest and the limits of anticonvulsant mood stabilizers (carbamazepine, valproic acid, gabapentin, lamotrigine, topiramate, oxcarbazepine) in the treatment of the so-called "noncognitive" symptoms of dementia. Their mechanism of action in mood disorders is not well known, but it would appear to be via the modulation of glutamate-mediated excitatory synaptic transmission and gamma-aminobutyric acid (GABA)-mediated inhibitory synaptic transmission that anticonvulsants might reduce behavioral symptoms in demented patients.

METHODS

The method employed in this work was a systematic bibliographic review, in which only the double-blind placebo-controlled studies or the clinically detailed enough open-labelled studies using validated scales were retained.

RESULTS

Among these medications, only carbamazepine demonstrated its efficacy in behavioral and psychological symptoms of dementia (BPSD) in controlled studies, notably that of Tariot et al. [J Am Geriatr Soc 42 (1994) 1160-1166 and Am J Psychiatry 155 (1998) 54-61] and Olin et al. [Am J Geriatr Psychiatry 9 (2001) 400-405], but with significant adverse events (sedation, hyponatremia, cardiac toxicity), particularly in the elderly and, being a strong enzymatic inducer, with a high likelihood of drug-drug interactions. Valproic acid showed some interesting results in BPSD within a large number of open studies and case reports. However, among the five controlled studies that have been published [Curr Ther Res 62 (2001) 51-67; Am J Geriatr Psychiatry 9 (2001) 58-66; Int J Geriatr Psychiatry 17 (2002) 579-585; Curr Alzheimer Res 2 (2005) 553-558 and Am J Geraitr Psychiatry 13 (2005) 942-945], none confirmed its efficacy on these symptoms. Regarding its tolerability in the geriatric population, no notable major side effect was reported (haematologic and hepatic effects are not more frequent than in the general population), except possible excessive sedation. Moreover, it appears that valproic acid could have neuroprotective effects, even if the contrary has been observed in a recent study. More studies need to be (and are being) conducted, notably on the interest of valproic acid in prophylaxis of BPSD. Gabapentin seems to be worthwhile and well tolerated in this indication, but no controlled study has been conducted to prove its efficacy, even if a quite important number of case reports and open studies have shown encouraging results. Concerning lamotrigine, which may potentially induce severe cutaneous side effects when administered with valproic acid, this drug has shown its efficacy in bipolar disorders and two recent case reports seem to indicate some interest in BPSD. Furthermore, lamotrigine appears to have neuroprotective effects. Although topiramate has shown interesting results in one open study in BPSD, its use in demented patients cannot be recommended because of its deleterious effect on cognitive functions. Oxcarbazepine, theoretically, could be an alternative to carbamazepine, which is, as aforesaid, the only anticonvulsant that proved its interest in BPSD. However, no clinical study has yet been published to support this hypothesis. This drug is better tolerated than carbamazepine, but induces severe and more frequent hyponatremia.

DISCUSSION AND CONCLUSION

Finally, although we all know that antipsychotics should no longer be prescribed in the elderly, the treatment of behavioral and psychological symptoms of dementia remains a difficult problem, considering the lack of a real alternative to these medications. Anticonvulsant mood stabilizers are an interesting solution but none of them, other than carbamazepine, which did, but which is not better tolerated than the usual drugs in this population - was able to prove its efficacy in this indication. Among these medications, valproic acid, gabapentin and lamotrigine should be studied further, and the neuroprotective effect of some of them is an interesting route for research.

Proteomic analysis of peripheral leukocytes in Alzheimer's disease patients treated with divalproex sodium

The molecular profiling of peripheral tissues, including circulating leukocytes, may hold promise in the discovery of biomarkers for diagnosing and treating neurodegenerative diseases, including Alzheimer's disease (AD). As a proof-of-concept, we performed a proteomics study on peripheral leukocytes from patients with AD both before and during treatment with divalproex sodium. Using two-dimensional gel electrophoresis and MALDI-TOF mass spectrometry, we identified 10 differentially expressed proteins: two up-regulated proteins, 14-3-3 protein epsilon and peroxiredoxin 2; and eight down-regulated proteins, actin-interacting protein, mitogen activated protein kinase 1, beta actin, annexin A1, glyceraldehyde 3-phosphate dehydrogenase, transforming protein RhoA, acidic leucine-rich nuclear phosphoprotein 32 family member B, and a currently unidentified protein. A subset was validated on both the transcript and protein levels in normal human peripheral blood mononuclear cell cultures treated with valproic acid. These proteins comprise a number of functional classes that may be important to the biology of AD and to the therapeutic action of valproate. These data also suggest the potential of using peripheral leukocytes to monitor pharmaceutical action for neurodegenerative diseases.

The Wnt-dependent signaling pathways as target in oncology drug discovery

Our current understanding of the Wnt-dependent signaling pathways is mainly based on studies performed in a number of model organisms including, Xenopus, Drosophila melanogaster, Caenorhabditis elegans and mammals. These studies clearly indicate that the Wnt-dependent signaling pathways are conserved through evolution and control many events during embryonic development. Wnt pathways have been shown to regulate cell proliferation, morphology, motility as well as cell fate. The increasing interest of the scientific community, over the last decade, in the Wnt-dependent signaling pathways is supported by the documented importance of these pathways in a broad range of physiological conditions and disease states. For instance, it has been shown that inappropriate regulation and activation of these pathways is associated with several pathological disorders including cancer, retinopathy, tetra-amelia and bone and cartilage disease such as arthritis. In addition, several components of the Wnt-dependent signaling pathways appear to play important roles in diseases such as Alzheimer’s disease, schizophrenia, bipolar disorder and in the emerging field of stem cell research. In this review, we wish to present a focused overview of the function of the Wnt-dependent signaling pathways and their role in oncogenesis and cancer development. We also want to provide information on a selection of potential drug targets within these pathways for oncology drug discovery, and summarize current data on approaches, including the development of small-molecule inhibitors, that have shown relevant effects on the Wnt-dependent signaling pathways.

Disease-modifying therapies in Alzheimer's disease: how far have we come?

Currently, there are no disease-modifying therapies available for Alzheimer's disease (AD). Acetylcholinesterase inhibitors and memantine are licensed for AD and have moderate symptomatic benefits. Epidemiological studies have suggested that NSAIDs, estrogen, HMG-CoA reductase inhibitors (statins) or tocopherol (vitamin E) can prevent AD. However, prospective, randomised studies have not convincingly been able to demonstrate clinical efficacy. Major progress in molecular medicine suggests further drug targets. The metabolism of the amyloid-precursor protein and the aggregation of its Abeta fragment are the focus of current studies. Abeta peptides are produced by the enzymes beta- and gamma-secretase. Inhibition of gamma-secretase has been shown to reduce Abeta production. However, gamma-secretase activity is also involved in other vital physiological pathways. Involvement of gamma-secretase in cell differentiation may preclude complete blockade of gamma-secretase for prolonged times in vivo. Inhibition of beta-secretase seems to be devoid of serious adverse effects according to studies with knockout animals. However, targeting beta-secretase is hampered by the lack of suitable inhibitors to date. Other approaches focus on enzymes that cut inside the Abeta sequence such as alpha-secretase and neprilysin. Stimulation of the expression or activity of alpha-secretase or neprilysin has been shown to enhance Abeta degradation. Furthermore, inhibitors of Abeta aggregation have been described and clinical trials have been initiated. Peroxisome proliferator activated receptor-gamma agonists and selected NSAIDs may be suitable to modulate both Abeta production and inflammatory activation. On the basis of autopsy reports, active immunisation against Abeta in humans seems to have proven its ability to clear amyloid deposits from the brain. However, a first clinical trial with active vaccination against the full length Abeta peptide has been halted because of adverse effects. Further trials with vaccination or passive transfer of antibodies are planned.

Memantine in the treatment of mild-to-moderate Alzheimer's disease

Memantine is the first and only medication that has been approved by European, US and Canadian regulatory agencies for the treatment of moderate-to-severe Alzheimer's disease (AD). It is an NMDA receptor antagonist that works to prevent excitotoxicity and cell death, which are mediated by the excessive influx of calcium during a sustained release of glutamate. Preclinical studies of memantine reveal that it has the potential to improve memory and learning processes after impairment has occurred, as well as to prevent further neuronal damage. Although memantine has been considered for the treatment of earlier AD, it has not yet been approved for this. Randomized controlled trials of memantine in the treatment of mild-to-moderate AD have demonstrated small treatment effects in measures of cognition, global assessment and behavior favoring the use of memantine. However, the differences between treatment groups were not consistently significant. Two ongoing long-term trials are further investigating the efficacy of memantine in the treatment of mild-to-moderate AD.

Alzheimer's disease: progress in the development of anti-amyloid disease-modifying therapies

The amyloid hypothesis--the leading mechanistic theory of Alzheimer's disease--states that an imbalance in production or clearance of amyloid beta (Abeta) results in accumulation of Abeta and triggers a cascade of events leading to neurodegeneration and dementia. The number of persons with Alzheimer's disease is expected to triple by mid-century. If steps are not taken to delay the onset or slow the progression of Alzheimer's disease, the economic and personal tolls will be immense. Different classes of potentially disease-modifying treatments that interrupt early pathological events (ie, decreasing production or aggregation of Abeta or increasing its clearance) and potentially prevent downstream events are in phase II or III clinical studies. These include immunotherapies; secretase inhibitors; selective Abeta42-lowering agents; statins; anti-Abeta aggregation agents; peroxisome proliferator-activated receptor-gamma agonists; and others. Safety and serious adverse events have been a concern with immunotherapy and gamma-secretase inhibitors, though both continue in clinical trials. Anti-amyloid disease-modifying drugs that seem promising and have reached phase III clinical trials include those that selectively target Abeta42 production (eg, tarenflurbil), enhance the activity of alpha-secretase (eg, statins), and block Abeta aggregation (eg, transiposate).

Clinical trials of amyloid-based therapies for Alzheimer's disease

We appear to be on the brink of a new epoch of treatment for Alzheimer's disease. Compelling evidence suggests that Aβ42 secretion is the triggering event in the pathogenesis of Alzheimer's disease, and that tau aggregation may be an important secondary event linked to neurodegeneration. Prophylactic administration of anti-amyloid agents designed to prevent Aβ accumulation in persons with subclinical disease is likely to be more effective than therapeutic interventions in established Alzheimer's disease. Drug development programs in Alzheimer's disease focus primarily on agents with anti-amyloid disease-modifying properties, and many different pharmacologic approaches to reducing amyloid pathology and tauopathy are being studied. Classes of therapeutic modalities currently in advanced-stage clinical trial testing include forms of immunotherapy (activeβ-amyloid immunoconjugate and human intravenous immunoglobulin), a γ-secretase inhibitor, the selective Aβ42-lowering agent R-flurbiprofen, and the anti-aggregation agent tramiprosate. Non-traditional dementia therapies such as the HMG-CoA reductase inhibitors (statins), valproate, and lithium are now being assessed for clinical benefit as anti-amyloid disease-modifying treatments. Positive findings of efficacy and safety from clinical studies are necessary but not sufficient to demonstrate that a drug has disease-modifying properties. Definitive proof of disease-modification requires evidence from validated animal models of Alzheimer's disease; rigorously controlled clinical trials showing a significantly improved, stabilized, or slowed rate of decline in cognitive and global function compared to placebo; and prospectively obtained evidence from surrogate biomarkers that the treatment resulted in measurable biological changes associated with the underlying disease process.

Memantine in the treatment of Alzheimer’s disease

Memantine is a moderate-affinity glutamate antagonist that primarily takes action at the N-methyl-D-aspartate receptor site. It has US FDA and European Medicines Agency approval for the treatment of moderate-to-severe Alzheimer’s disease. Memantine replaces Mg2+ at the N-methyl-D-aspartate receptor, blocking pathological glutamate activity but allowing normal glutamate action at this site. Consequently, calcium homeostasis is better maintained, reducing slow after hyperpolarization and preventing neuronal excitotoxicity and cell death. Clinical trials have shown that memantine is generally safe and well tolerated, and have provided evidence for its efficacy as assessed by cognitive, behavioral, functional and global measures. It has also been shown to be well tolerated and effective in the treatment of moderate-to-severe Alzheimer’s disease when patients received previous and ongoing treatment with donepezil. The tolerability and efficacy of memantine is under continued investigation in milder Alzheimer’s disease and other forms of dementia.

Antipsychotic Drug Use Among Nursing Home Residents Taking Rivastigmine

OBJECTIVE

To evaluate whether or not rivastigmine use is associated with a decrease in the initiation of antipsychotic drug therapy among nursing home residents in the United States.

METHODS

A retrospective analysis was performed using Minimum Data Set data and physician order files for newly admitted residents of 452 US nursing facilities from 2000 through 2002. The rivastigmine group included those who were diagnosed with Alzheimers disease (AD) and began rivastigmine treatment within 30 days of diagnosis. Patients were required to be on treatment for a minimum of 30 days. The control group included those who were diagnosed with AD, but did not receive a cholinesterase inhibitor. All subjects were antipsychotic drug-naive within 30 days of baseline (initiation of rivastigmine or initial AD diagnosis). A Cox proportional hazards model was used to estimate predicted risk of antipsychotic drug use.

RESULTS

This study included 845 patients in the rivastigmine group and 517 patients in the control group. The rivastigmine group had fewer female patients, was younger, and had more verbal distress, sleep issues, sadness, loss of interest, and behavioral symptoms at baseline compared with the control group (P < .01). Overall initiation of antipsychotics was lower in the rivastigmine group (8.6%) compared with the control group (17.0%). Patients in the control group were almost 2 times more likely (relative risk = 1.86; P < .001) to take antipsychotics compared with patients taking rivastigmine, after adjusting for demographic covariates and mental health conditions or behavioral symptoms at baseline. Patients with baseline mental health conditions or behavioral symptoms were more likely to start antipsychotics than those without such conditions (P < .001).

CONCLUSIONS

Study results suggest that nursing home residents with Alzheimers disease treated with rivastigmine have a reduced risk of initiating therapy with an antipsychotic drug compared with residents who do not receive cholinesterase inhibitor treatment.

Les symptômes psychologiques et comportementaux de la démence : description et prise en charge

Behavioral and Psychological Symptoms in Dementia (BPSD) are, beside cognitive disorders, major features of Alzheimer's disease and related disorders. Diagnosis is important to enhance our knowledge of the pathophysiology of dementia and of their functional consequences for patients and caregivers. Pharmacological and non-pharmacological management of dementia depends to a large extent on the presence of BPSD. A committee of geriatricians, neurologists and psychiatrists specialized in dementia (THEMA 2) has promoted an epidemiological, diagnostic and therapeutic update in this field. This work was based on the BPSD Consensus Conference Report edited in 2000 by the International Psychogeriatric Association. This report was updated with the most recent literature reports, and was adapted to the French environment. This paper is a synthesis of this meeting, validated and corrected by the entire Thema 2 group.

Effect of Divalproex Sodium on Behavioural and Cognitive Problems in Elderly Dementia

BACKGROUND

Behavioural and psychological symptoms of dementia (BPSD) occur in up to 90% of individuals with dementia at some point in their illness. BPSD reduce patient quality of life, cause great distress to caregivers and are the most common reason for institutionalisation. In nursing homes, pharmacological measures (usually antipsychotics or benzodiazepines) are often required to control agitation and aggression in patients with dementia. However, no medications have been approved by the US Food and Drug Administration for this indication as yet. The antiepileptic agent divalproex sodium may have advantages in this setting because of lower rates of drug interactions and adverse effects in this patient population.

OBJECTIVE

The aim of the study was to assess the impact of treatment with divalproex sodium on behavioural, mood and cognitive measures in a population of elderly nursing home residents with a history of behaviour problems associated with dementia.

MATERIALS AND METHODS

The study was a retrospective analysis of a long-term care database which allowed assessment of the impact of divalproex sodium therapy on behavioural, mood and cognitive measures in elderly nursing home residents with a history of dementia-related behaviour problems. Minimum Data Set items relating to problems of behaviour, cognition and mood were collected prior to and after divalproex sodium treatment over a 1-year period. Two-phase generalised linear regression, with fixed intersections at the time of divalproex sodium initiation, was used to estimate trends in each measure prior to and after divalproex sodium initiation. Monotherapy, combination therapy with benzodiazepines and antipsychotics, and dose comparisons of divalproex sodium were studied.

RESULTS

In all three situations (i.e. as monotherapy, in combination with benzodiazepines and antipsychotics, and at both higher and lower doses), divalproex sodium therapy was shown to have multiple beneficial effects on various behavioural, mood and cognition indicators in elderly nursing home residents. In general, the data seemed to support more favourable results for the higher divalproex sodium dose group.

CONCLUSIONS

These data support the use of divalproex sodium in elderly nursing home residents with a history of dementia and behaviour problems and warrant conduct of prospective, randomised trials of the drug in this setting.

Pharmacologic management of agitation in Alzheimer's disease

A large body of evidence has accrued that neuropsychiatric disturbances, such as agitation, are extremely common in Alzheimer's disease. These disturbances are associated with considerable morbidity including earlier nursing home admission, more rapid progression, exacerbation of functional and cognitive deficits, and increased caregiver distress. When attention to social or environmental causes, medical conditions, or other triggers of the behavioral disturbance fails to yield improvement, a role for medication may be indicated, whereby the most dominant behavioral target symptoms are matched to the most relevant medication class. Evidence is reviewed for various medication classes in treating agitation in the patient with Alzheimer's disease, and future treatment strategies may be aimed at delaying or preventing such neuropsychiatric disturbances.

Neuroprotective activities of sodium valproate in a murine model of human immunodeficiency virus-1 encephalitis

Human immunodeficiency virus-1 (HIV-1) infection of the nervous system can result in neuroinflammatory events leading first to neuronal dysfunction then to cognitive and behavioral impairments in infected people. The multifaceted nature of the disease process, commonly called HIV-1-associated dementia (HAD), provides a number of adjunctive therapeutic opportunities. One proposed adjunctive therapy is sodium valproate (VPA), an anticonvulsant known to promote neurite outgrowth and increase beta-catenin through inhibiting glycogen synthase kinase 3beta activity and tau phosphorylation. We now show that VPA treatment of rat cortical neurons exposed to HIV-1 gp120 prevents resultant neurotoxic activities. This includes the induction of significant neurite outgrowth and microtubule-associated protein 2 (MAP-2) and neuron-specific nuclear protein (NeuN) antigens in affected neuronal cell bodies and processes. Similarly, VPA protects severe combined immunodeficient (SCID) mice against the neurodegeneration of HIV-1ADA infected monocyte-derived macrophages (MDMs). In SCID mice with HIV-1 MDM-induced encephalitis, VPA treatment significantly reduced neuronal phosphorylatedbeta-catenin and tau without affecting HIV-1 replication or glial activation. We conclude that VPA protects neurons against HIV-1 infected MDM neurotoxicity, possibly through its effects on the phosphorylation of tau and beta-catenin. The use of VPA as an adjuvant in treatment of human HAD is being pursued.

Current Treatment for Alzheimer Disease and Future Prospects

A cascade of pathophysiological events is triggered in Alzheimer disease (AD) that ultimately involves common cellular signaling pathways and leads to cellular and network dysfunction, failure of neurotransmission, cell death, and a common clinical outcome. The process is asynchronous, meaning that viable neurons remain as targets for therapy even in the diseased state, and each stage of the cascade affords the possibility for therapeutic intervention. Cholinesterase inhibitors are the only available treatment in the United States for patients with mild to moderate AD, helping maintain cognitive and functional abilities in most patients and conferring beneficial behavioral effects in some. Memantine is an NMDA receptor antagonist that has recently been approved in Europe for treatment of moderately severe to severe AD and is under investigation in the United States. Its mechanism of action may include enhanced neurotransmission in several systems as well as antiexcitotoxic effects. There are data regarding the effectiveness of the combination of memantine with cholinesterase inhibitors that will be useful for the practicing clinician. Other agents have shown some benefit in clinical trials, including the antioxidants vitamin E, selegiline, and Ginkgo biloba extracts, although the weight of evidence regarding their effects is not sufficient to define clinical practice. Potential future therapies currently are in development that target multiple aspects of the illness cascade, including aberrant inflammation, neurotrophic function, and processing of beta amyloid and tau proteins. These newer approaches hold promise for disease modification but are as yet unproven. Whether or not disease-modifying or preventive therapies become a reality, clinicians will be faced with AD patients who require treatment at all stages of illness for the indefinite future. Cholinergic and emerging noncholinergic medications will likely prevail as the standards of treatment for years to come.