Benzodiazepines may have protective effects against Alzheimer disease

The neurotransmitter puzzle of Alzheimer's: Dissecting mechanisms and exploring therapeutic horizons

Alzheimer's Disease (AD) represents a complex interplay of neurological pathways and molecular mechanisms, with significant impacts on patients' lives. This review synthesizes the latest developments in AD research, focusing on both the scientific advancements and their clinical implications. We examine the role of microglia in AD, highlighting their contribution to the disease's inflammatory aspects. The cholinergic hypothesis, a cornerstone of AD research, is re-evaluated, including the role of Alpha-7 Nicotinic Acetylcholine Receptors in disease progression. This review places particular emphasis on the neurotransmission systems, exploring the therapeutic potential of GABAergic neurotransmitters and the role of NMDA inhibitors in the context of glutamatergic neurotransmission. By analyzing the interactions and implications of neurotransmitter pathways in AD, we aim to shed light on emerging therapeutic strategies. In addition to molecular insights, the review addresses the clinical and personal aspects of AD, underscoring the need for patient-centered approaches in treatment and care. The final section looks at the future directions of AD research and treatment, discussing the integration of scientific innovation with patient care. This review aims to provide a comprehensive update on AD, merging scientific insights with practical considerations, suitable for both specialists and those new to the field.

Impaired sleep is associated with tau deposition on 18F-flortaucipir PET and accelerated cognitive decline, accounting for medications that affect sleep

BACKGROUND

Impaired sleep is commonly associated with Alzheimer's disease (AD), although the underlying mechanisms remain unclear. Furthermore, the moderating effects of sleep-affecting medications, which have been linked to AD pathology, are incompletely characterized. Using data from the Alzheimer's Disease Neuroimaging Initiative, we investigated whether a medical history of impaired sleep, informant-reported nighttime behaviors, and sleep-affecting medications are associated with beta-amyloid and tau deposition on PET and cognitive change, cross-sectionally and longitudinally.

METHODS

We included 964 subjects with 18F-florbetapir PET scans. Measures of sleep impairment and medication use were obtained from medical histories and the Neuropsychiatric Inventory Questionnaire. Multivariate models, adjusted for covariates, were used to assess associations among sleep-related features, beta-amyloid and tau, and cognition. Cortical tau deposition, categorized by Braak stage, was assessed using the standardized uptake value peak alignment (SUVP) method on 18F-flortaucipir PET.

RESULTS

Medical history of sleep impairment was associated with greater baseline tau in the meta-temporal, Braak 1, and Braak 4 regions (p = 0.04, p < 0.001, p = 0.025, respectively). Abnormal nighttime behaviors were also associated with greater baseline tau in the meta-temporal region (p = 0.024), and greater cognitive impairment, cross-sectionally (p = 0.007) and longitudinally (p < 0.001). Impaired sleep was not associated with baseline beta-amyloid (p > 0.05). Short-term use of selective serotonin reuptake inhibitors and benzodiazepines slightly weakened the sleep-tau relationship.

CONCLUSIONS

Sleep impairment was associated with tauopathy and cognitive decline, which could be linked to increased tau secretion from neuronal hyperactivity. Clinically, our results help identify high-risk individuals who could benefit from sleep-related interventions aimed to delay cognitive decline and AD.

Insights on benzodiazepines' potential in Alzheimer's disease

Alzheimer's disease (AD) is the most frequent type of dementia characterized by the deposition of amyloid beta (Aβ) plaque and tau-neurofibrillary tangles (TNTs) in the brain. AD is associated with the disturbances of various neurotransmitters including gamma-aminobutyric acid (GABA). Of note, GABA is reduced in AD, and restoration of GABA effect by benzodiazepines (BDZs) may improve AD outcomes. However, BDZs may adversely affect cognitive functions chiefly in elderly AD patients with sleep disorders. Besides, there is a controversy regarding the use of BDZs in AD. Consequently, the objective of the present review was to disclose the possible role of BDZs on the pathogenesis of AD that might be beneficial, neutral, or detrimental effects on AD. Prolonged use of intermediate-acting BDZ lorazepam exerts amnesic effects due to attenuation of synaptic plasticity and impairment of recognition memory. However, BDZs may have a protective effect against the development of AD by reducing tau phosphorylation, neuroinflammation, and progression of AD neuropathology. On the other side, other findings highlighted that extended use of BDZs was not associated with the development of AD. In conclusion, there are controversial points concerning the use of BDZs and the risk for the progression of AD. Thus, preclinical, and clinical studies are essential in this regard.

Benzodiazepines in Alzheimer's disease: beneficial or detrimental effects

Dementia is considered a clinical syndrome characterized by cognitive dysfunction and memory loss. Alzheimer's disease (AD) is the most common type of dementia. AD is linked with the turbulence of diverse neurotransmitters including gamma-aminobutyric acid (GABA). Notably, GABA in the brain and cerebrospinal fluid was reduced in AD. Thus, allosteric modulation of the GABA effect by benzodiazepines (BDZs) may improve the clinical outcomes of AD patients. Therefore, the objective of the present review was to reveal the possible role of BDZs on the pathogenesis and clinical outcomes in AD patients. Though BDZs may adversely affect cognitive functions mainly in elderly patients, herein it was postulated that BDZs may have beneficial, neutral, or detrimental effects in AD. Taken together, there is strong controversy regarding the use of BDZs and the risk for the development of AD. Therefore, experimental, preclinical and clinical studies are critical to determine the potential protective or detrimental effects of BDZs on AD neuropathology.

An avoidable crisis

In Scotland drug policy and consequently the progress of evidence-based treatment options has been struggling for many years. Political inaction is brought about by a complex chain of legal and operational obstructions with local authorities deferring to national Government which in turn is paralysed by international convention. Scotland represents a case study demonstrating the adverse consequences of management by non medical requirements rather than implementation of a clinically proven progressive policy. The difficulty of translating theory and evidence into practice is acknowledged but suggestions are made for pragmatic and humanitarian initiatives.

The association between benzodiazepine use and greater risk of neurocognitive impairment is moderated by medical burden in people with HIV

Benzodiazepine use is linked to neurocognitive impairment (NCI) in the general population and people with HIV (PWH); however, this relationship may depend on age-related factors such as medical comorbidities, which occur at an elevated rate and manifest earlier in PWH. We retrospectively examined whether chronological age or medical burden, a clinical marker for aging, moderated the relationship between benzodiazepine use and NCI in PWH. Participants were 435 PWH on antiretroviral therapy who underwent neurocognitive and medical evaluations, including self-reported current benzodiazepine use. A medical burden index score (proportion of accumulated multisystem deficits) was calculated from 28 medical deficits. Demographically corrected cognitive deficit scores from 15 neuropsychological tests were used to calculate global and domain-specific NCI based on established cut-offs. Logistic regressions separately modeled global and domain-specific NCI as a function of benzodiazepine x age and benzodiazepine x medical burden interactions, adjusting for current affective symptoms and HIV disease characteristics. A statistically significant benzodiazepine x medical burden interaction (p = .006) revealed that current benzodiazepine use increased odds of global NCI only among those who had a high medical burden (index score > 0.3 as indicated by the Johnson–Neyman analysis), which was driven by the domains of processing speed, motor, and verbal fluency. No age x benzodiazepine interactive effects on NCI were present. Findings suggest that the relationship between BZD use and NCI among PWH is specific to those with greater medical burden, which may be a greater risk factor for BZD-related NCI than chronological age.

The effects of a multi-disciplinary team on sleep quality assessment in mild-to-moderate Alzheimer's disease patients with sleep disorders

BACKGROUND AND AIMS

Sleep disturbances are a severe problem among patients with Alzheimer's disease (AD). By evaluating sleep quality in mild-to-moderate AD patients, this study aimed to assess the effects of multi-disciplinary team (MDT) in reducing the incidence of adverse reactions of AD patients. The reduction in the incidence of adverse reactions to predict multi-disciplinary team (MDT) treatment effects.

METHODS AND RESULTS

This study included 60 mild-to-moderate AD patients with sleep problems when hospitalized in Huzhou Third Municipal Hospital. The patients were randomly distributed into two groups, routine and MDT treatments. The cognitive functions, sleep conditions, and psycho-behavioral symptoms were compared between both the groups. Cognitive function declined significantly between pretherapy and follow-up in the routine treatment group (MMSE: t = -7.961, P < 0.001; MoCA: t = -4.672, P < 0.001). There was a significant decline in drowsiness in the MDT group compared to that in the routine treatment group (χ² = 4.320, P = 0.038). Sleep quality improved significantly during the follow-up in the MDT treatment group (t = 6.098, P < 0.001). The results of the Hamilton Depression Scale (HAMD) and Hamilton Anxiety Scale (HAMA) among family caregivers (FCGs) demonstrated that MDT treatment could alleviate caregivers' depression (t = -2.867, P = 0.042), and routine treatment can worsen their anxiety (t = 3.258, P = 0.003).

CONCLUSION

The MDT treatment method as an effective and meaningful therapy can help mitigate the suffering of patients with AD and FCGs.

Neurophysiological biomarkers using transcranial magnetic stimulation in Alzheimer's disease and mild cognitive impairment: A systematic review and meta-analysis

Transcranial magnetic stimulation (TMS) is a non-invasive neurophysiological tool that enables the investigation of cortical excitability in the human brain. Paired-pulse TMS paradigms include short- and long-interval intracortical inhibition (SICI/LICI), intracortical facilitation (ICF), and short-latency afferent inhibition (SAI), which can assess neurophysiological functions of GABAergic, glutamatergic, and cholinergic neural circuits, respectively. We conducted the first systematic review and meta-analysis to compare these TMS indices among patients with AD, mild cognitive impairment (MCI), and healthy controls (HC). Our meta-analyses indicated that RMT, SAI, SICI, and LICI were significantly lower in patients with AD, while ICF did not show a difference in patients with AD compared with HC. In patients with MCI, RMT and SAI were significantly lower than in HC. In conclusion, motor cortical excitability was increased, while cholinergic function was decreased in AD and MCI in comparison with HC and patients with AD had decreased GABAergic and glutamatergic functions compared with HC. Our results warrant further studies to differentiate AD, MCI, and HC, employing multimodal TMS neurophysiology.

Associations of Benzodiazepines, Z-Drugs, and Other Anxiolytics With Subsequent Dementia in Patients With Affective Disorders: A Nationwide Cohort and Nested Case-Control Study

OBJECTIVE

Benzodiazepines and Z-drugs are two of the most prescribed agents worldwide. However, because of their cognitive side effects, the question of their influence on the risk of dementia has been raised. The authors examined the association of benzodiazepines, Z-drugs, and other anxiolytics with incident dementia in patients with affective disorders.

METHODS

The authors conducted a cohort and nested case-control study of 235,465 patients over age 20 who were identified in the Danish National Patient Registry as having had a first-time hospital contact for an affective disorder between 1996 and 2015. From the Danish National Prescription Registry, information was obtained on all prescriptions for benzodiazepines, Z-drugs, and other anxiolytics, and patients were followed for incident dementia (defined by hospital discharge diagnosis or acetylcholinesterase inhibitor use). Cox proportional hazards and conditional logistic regression models were used to calculate hazard ratios and odds ratios with adjustment for sociodemographic and clinical variables.

RESULTS

A total of 75.9% (N=171,287) of patients had any use of benzodiazepines or Z-drugs, and during the median follow-up of 6.1 years (interquartile range, 2.7-11), 9,776 (4.2%) patients were diagnosed with dementia. Any use of benzodiazepines or Z-drugs showed no association with dementia after multiple adjustments in either the cohort analysis or a nested case-control design. In the cohort analysis, the number of prescriptions and the cumulated dose of benzodiazepines or Z-drugs at baseline were not associated with dementia. In the nested case-control study, where prescriptions were counted from 1995 until 2 years before the index date, there was a slightly higher odds ratio of dementia in patients with the lowest use of benzodiazepines or Z-drugs (odds ratio=1.08, 95% CI=1.01, 1.15) compared with no lifetime use. However, patients with the highest use had the lowest odds of developing dementia (odds ratio=0.83, 95% CI=0.77, 0.88).

CONCLUSIONS

This large cohort study did not reveal associations between use of benzodiazepines or Z-drugs and subsequent dementia, even when exposures were cumulated or divided into long- and short-acting drugs. Some results were compatible with a protective effect.

Is Long-Term Benzodiazepine Use a Risk Factor for Cognitive Decline? Results of a Systematic Review

Background and Aims

Benzodiazepines have been widely used for long periods of time despite their adverse effects. The acute effects on cognition are well established. However, less is known about the long-term effects. This study critically reviewed existing evidence of the association between long-term exposure to benzodiazepines and risk of cognitive decline in adults.

Methods

A systematic review with narrative synthesis was conducted. PubMed and PsycINFO databases were searched using combinations of keywords related to “benzodiazepines” and “cognitive function” from database inception to 12 February 2018 to identify prospective longitudinal studies. The records were evaluated for relevance according to the inclusion and exclusion criteria.

Results

Fourteen studies involving 2145 long-term benzodiazepine users were included. Meta-analysis was not undertaken because the combined result would not be meaningful as the included studies differed in several key aspects such as frequency and duration of benzodiazepine use, follow-up periods, cognitive domains, cognitive tests, scoring systems, and statistical analysis. The definition of long-term benzodiazepine use was problematic in all the studies. The exposure was determined by measures which were assumed to represent the whole period in-between the follow-ups. Only 3 of the 14 studies provided support for an association between long-term benzodiazepine use and cognitive decline with a small to medium effect size. However, these three studies used different methods to assess the strength of this association. Global cognitive functioning, verbal memory, intelligence, psychomotor speed, and speed of processing were the cognitive domains affected which also varied across these three studies.

Conclusions

Little evidence of an association between long-term benzodiazepine use and a higher risk of cognitive decline among the general adult population was found. However, discrepancies among the results and inconsistencies regarding the cognitive domains affected and methodological limitations prevent definite conclusions. Therefore, future research with prospective studies specially designed would be of great value.

Benzodiazepines and Related Drugs as a Risk Factor in Alzheimer's Disease Dementia

Benzodiazepines (BZDs) and Z-drugs are compounds widely prescribed in medical practice due to their anxiolytic, hypnotic, and muscle relaxant properties. Yet, their chronic use is associated with cases of abuse, dependence, and relapse in many patients. Furthermore, elderly people are susceptible to alterations in pharmacodynamics, pharmacokinetics as well as to drug interaction due to polypharmacy. These situations increase the risk for the appearance of cognitive affectations and the development of pathologies like Alzheimer's disease (AD). In the present work, there is a summary of some clinical studies that have evaluated the effect of BZDs and Z-drugs in the adult population with and without AD, focusing on the relationship between their use and the loss of cognitive function. Additionally, there is an assessment of preclinical studies focused on finding molecular proof on the pathways by which these drugs could be involved in AD pathogenesis. Moreover, available data (1990-2019) on BZD and Z-drug use among elderly patients, with and without AD, was compiled in this work. Finally, the relationship between the use of BZD and Z-drugs for the treatment of insomnia and the appearance of AD biomarkers was analyzed. Results pointed to a vicious circle that would worsen the condition of patients over time. Likewise, it put into relevance the need for close monitoring of those patients using BZDs that also suffer from AD. Consequently, future studies should focus on optimizing strategies for insomnia treatment in the elderly by using other substances like melatonin agonists, which is described to have a much more significant safety profile.

Benzodiazepines, z-Hypnotics, and Risk of Dementia: Special Considerations of Half-Lives and Concomitant Use

The utilization of benzodiazepines (BZDs) and z-hypnotics has substantially increased with the aging of the population, but the risk of BZDs and z-hypnotics in the development of dementia remains a strong concern. This cohort study aimed to evaluate the risk of BZDs and z-hypnotics for subsequent dementia development with a special consideration of their half-lives and the concomitant use of these medications. People aged 65 years and older who were newly prescribed oral BZDs or z-hypnotics between 2003 and 2012 were identified from Taiwan's National Health Insurance Research Database. All BZDs were categorized as long-acting drugs (≥ 20 h) or short-acting drugs (< 20 h) for further comparisons, and data were collected on a quarterly basis, starting on the first date of drug prescription and ending on the date of death, occurrence of dementia, or end of the follow-up period (December 31, 2012), whichever came first. All dementia events except vascular dementia occurring during the follow-up period were identified. Among 260,502 eligible subjects, short-acting BZDs and z-hypnotics users were at greater risk of dementia than long-acting users [adjusted odds ratio (95% confidence interval) in short-acting BZD users, 1.98 (1.89-2.07); z-hypnotic users, 1.79 (1.68-1.91); and long-acting BZD users, 1.47 (1.37-1.58)]. In addition, subjects concomitantly using 2 or more BZDs or z-hypnotics had a higher risk of dementia than those who used 1 of these drugs (4.79 (3.95-5.81)). The use of BZDs and z-hypnotics was strongly associated with the risk of dementia development, especially the short-acting BZDs, z-hypnotics, and concomitant use of multiple agents. These findings deserve further interventional studies for clarification.

Benzodiazepine use and the risk for dementia

Emerging evidence indicates that the use of benzodiazepines among older adults may increase the risk of development of dementia. A review of the literature identified 13 studies investigating this link. Eight studies found a positive association between the use of benzodiazepines and development of dementia. Two studies found no such association, two had mixed results and one study found that benzodiazepine use reduced the incidence of dementia. As none of these studies were controlled prospective studies, causality could not be ascertained. The association identified between the use of benzodiazepines and the development of dementia is a cause for concern among older adults.

Risk of Dementia in Long-Term Benzodiazepine Users: Evidence from a Meta-Analysis of Observational Studies

Background and Purpose

There is conflicting evidence in the literature on the association between benzodiazepines (BDZs) and the risk of dementia. This meta-analysis aimed to determine the relationship between the long-term usage of BDZs and the risk of dementia.

Methods

The PubMed and Embase databases were systematically searched for relevant publications up to September 2017. The literature search focused on observational studies that analyzed the relationship between the long-term use of BDZs and the risk of dementia. Pooled rate ratios (RRs) with 95% confidence interval (CI) were assessed using a random-effects model. The robustness of the results was checked by performing subgroup and sensitivity analyses.

Results

Ten studies were included: six case–control and four cohort studies. The pooled RR for developing dementia was 1.51 (95% CI=1.17–1.95, p=0.002) in patients taking BDZ. The risk of dementia was higher in patients taking BDZs with a longer half-life (RR=1.16, 95% CI=0.95–1.41, p=0.150) and for a longer time (RR=1.21, 95% CI=1.04–1.40, p=0.016).

Conclusions

This meta-analysis that pooled ten studies has shown that BDZ significantly increases the risk of dementia in the elderly population. The risk is higher in patients taking BDZ with a longer half-life (>20 hours) and for a longer duration (>3 years).

Use of sedative-hypnotics and the risk of Alzheimer's dementia: A retrospective cohort study

There has been a growing interest in the relationship between sedative-hypnotics use and the risk of Alzheimer's dementia (AD) risk. This study aimed to evaluate the risk of AD associated with the use of sedative-hypnotics. A retrospective cohort study was conducted with randomly selected 5% samples from ≥50 years old beneficiaries of National Health Insurance Service (NHIS) of Korea from January 2002 to December 2015. The exposure to sedative-hypnotics was defined when prescribed over 30 defined daily dose (DDD) after January 2004 and it was categorized by prescribed dosage, types and half-lives of benzodiazepines. Time-dependent Cox regression model with a lag period of 5-years was used to evaluate the association between use of sedative-hypnotics and the risk of subsequent AD. Sensitivity analysis was performed for restricting sedative-hypnotics only when prescribed with insomnia. A total of 268,170 subjects were identified and subjects exposed to sedative-hypnotics showed a higher risk of AD (HR: 1.79; 95% CI: 1.72-1.86) than those who were not. There was an increased risk of AD among subjects exposed to benzodiazepines or zolpidem (HR: 1.75; 95% CI: 1.67-1.82) and antidepressants or low-dose antipsychotics (HR: 1.63; 95% CI: 1.42-1.87). The risk of AD was increased regardless of dose of sedative-hypnotics and half-life among benzodiazepines, especially in exposure to more than 360 DDD of sedative-hypnotics (HR: 1.78; 95% CI: 1.60-1.99) and the long-acting benzodiazepine (HR:1.77; 95% CI: 1.65-1.89).

The risk of Alzheimer's disease associated with benzodiazepines and related drugs: a nested case-control study

OBJECTIVE

To assess the association between benzodiazepine and related drug (BZDR) use and risk of Alzheimer's disease (AD) with cumulative consumption and duration of use based models.

METHOD

A nationwide nested case-control study of all Finnish community-dwelling persons who received clinically verified AD diagnosis in 2005-2011 (N = 70 719) and their matched controls (N = 282 862). AD diagnosis was based on DSM-IV and NINCDS-ADRDA criteria. BZDR purchases were extracted from the Prescription Register since 1995. The association between BZDR use and AD was assessed using conditional logistic regression with 5-year lag time between exposure and outcome.

RESULTS

Benzodiazepine and related drug use was associated with modestly increased risk of AD (adjusted OR 1.06, 95% CI 1.04-1.08). A dose-response relationship was observed with both cumulative consumption and duration. Adjustment for other psychotropics removed the cumulative dose-response relationship by attenuating the ORs in the highest dose category.

CONCLUSION

Benzodiazepine and related drug use in general was associated with modestly increased risk of AD. No major differences were observed between different subcategories of BZDRs (i.e. benzodiazepines, Z drugs, short-/medium-acting or long-acting BZDRs). As dose-response relationship abolished after adjustment for other psychotropics, it is possible that the association may partially be due to antidepressants and/or antipsychotics, or concomitant use of these medications.

A Systematic Review and Meta-Analysis of the Risk of Dementia Associated with Benzodiazepine Use, After Controlling for Protopathic Bias

BACKGROUND

Benzodiazepine use is highly prevalent in elderly and late middle-aged populations and may be associated with an increased risk of dementia. Observational studies have suggested that benzodiazepine use may increase the risk of dementia, however there have been significant concerns regarding protopathic bias in these studies, precluding conclusive findings.

OBJECTIVE

The aim of our study was to investigate the risk of dementia associated with the use of benzodiazepines in elderly patients, after controlling for protopathic bias.

METHODS

We identified observational studies with more than 50 cases, adequate assessment of benzodiazepine exposure, and reliable dementia diagnosis ascertainment, from the MEDLINE, PubMed, EMBASE, CINAHL, LILACS and CENTRAL electronic databases through to 5 June 2018, with no language limits. The association of any current or former use of short- or long-acting benzodiazepines with incident dementia was analysed. A subgroup analysis was performed by the introduction of lag time to assess the effect of protopathic bias. We also performed analyses considering the effect of higher benzodiazepine cumulative doses and adjustment for psychiatric covariates. Study quality was investigated using the Newcastle-Ottawa Scale.

RESULTS

We identified 15 studies reported in 14 articles, involving 159,090 cases. Ever use of benzodiazepines was associated with a significantly increased risk of dementia [odds ratio (OR) 1.39, 95% confidence interval (CI) 1.21-1.59]. Those studies that implemented the longest lag times of ≥ 5 years, and hence most likely to overcome protopathic bias, found a risk estimate that was marginally attenuated, but still significant (OR 1.30, 95% CI 1.14-1.48). Long-acting benzodiazepines were associated with a marginally higher magnitude risk (OR 1.21, 95% CI 0.99-1.49) than short-acting benzodiazepines (OR 1.13, 95% CI 1.02-1.26), although the former failed to reach statistical significance (p = 0.059).

CONCLUSIONS

Our findings indicate that the association between benzodiazepine use and dementia incidence is not purely an artefact due to protopathic bias. Reduction of inappropriate benzodiazepine prescription is likely to attenuate dementia risk.

Use of benzodiazepines and cognitive performance in primary care patients with first cognitive complaints

ABSTRACTThe aim of the present study is to investigate the impact of benzodiazepine use on cognitive performance in primary care patients with first cognitive complaints. The association between the exposition to benzodiazepines (short and long half-life) and cognitive performance, evaluated through the Mini Mental State Examination (MMSE), was tested through analysis of the covariance and logistic regression models. Within the 4,249 participants (mean age 77.0 ± 8.2, 66.4% women), 732 (17%) were on benzodiazepines. When compared with non-users, short- and long-acting benzodiazepine users presented overlapping adjusted MMSE mean scores (respectively, mean MMSE score: 25.3, 95%CI 25.2-25.5; 25.4, 95%CI 25.1-25.7, and 25.9, 95%CI 25.3-26.4; p = 0.156). When tested according to the logistical regression model, after adjusting for potential confounders, no association was found between short and long acting benzodiazepine use and a MMSE < 24 (respectively, OR 0.9, 95%CI 0.7-1.2; OR 0.8, 95%CI 0.7-1.3) as compared with non-users. In conclusion, according to the results of our study, benzodiazepine use seems not to impact on cognitive performance- as assessed with the MMSE- of primary care patients referring to GPs for first cognitive complaints.

Regular Benzodiazepine and Z-Substance Use and Risk of Dementia: An Analysis of German Claims Data

BACKGROUND

While acute detrimental effects of benzodiazepine (BDZ), and BDZ and related z-substance (BDZR) use on cognition and memory are known, the association of BDZR use and risk of dementia in the elderly is controversially discussed. Previous studies on cohort or claims data mostly show an increased risk for dementia with the use of BDZs or BDZRs. For Germany, analyses on large population-based data sets are missing.

OBJECTIVE

To evaluate the association between regular BDZR use and incident any dementia in a large German claims data set.

METHODS

Using longitudinal German public health insurance data from 2004 to 2011 we analyzed the association between regular BDZR use (versus no BDZR use) and incident dementia in a case-control design. We examined patient samples aged≥60 years that were free of dementia at baseline. To address potential protopathic bias we introduced a lag time between BDZR prescription and dementia diagnosis. Odds ratios were calculated applying conditional logistic regression, adjusted for potential confounding factors such as comorbidities and polypharmacy.

RESULTS

The regular use of BDZRs was associated with a significant increased risk of incident dementia for patients aged≥60 years (adjusted odds ratio [OR] 1.21, 95% confidence interval [CI] 1.13-1.29). The association was slightly stronger for long-acting substances than for short-acting ones. A trend for increased risk for dementia with higher exposure was observed.

CONCLUSION

The restricted use of BDZRs may contribute to dementia prevention in the elderly.

Benzodiazepine Use and Cognitive Decline in Elderly With Normal Cognition

Benzodiazepine (BZD) use may be associated with dementia. However, differing opinions exist regarding the effect of BZDs on long-term changes in cognition. We evaluated the association between BZD use and cognitive decline in the elderly with normal cognition from the National Alzheimer's Disease Coordinating Center's Uniform Data Set. The study exposure, BZD use, was classified 2 ways: any-use [reported BZD use at a minimum of 1 Alzheimer's disease center (ADC) visit] and always-use (reported BZD use at all ADC visits). The reference group included participants without any declared BZD use at any Alzheimer's Disease Center (ADC) visit. The main outcome measures were Clinical Dementia Rating Sum of Boxes score and Mini-Mental State Examination score. We observed a decline in cognitive status over time in the 2 comparison groups. All participants who reported taking BZDs had poorer cognitive performance at all visits than nonusers. However, cognitive decline was statistically similar among all participants. We found no evidence of an association between BZD use and cognitive decline. The poor cognitive performance in BZD users may be due to prodromal symptoms caused by preclinical dementia processes.

Towards a Better Understanding of GABAergic Remodeling in Alzheimer's Disease

γ-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the vertebrate brain. In the past, there has been a major research drive focused on the dysfunction of the glutamatergic and cholinergic neurotransmitter systems in Alzheimer’s disease (AD). However, there is now growing evidence in support of a GABAergic contribution to the pathogenesis of this neurodegenerative disease. Previous studies paint a complex, convoluted and often inconsistent picture of AD-associated GABAergic remodeling. Given the importance of the GABAergic system in neuronal function and homeostasis, in the maintenance of the excitatory/inhibitory balance, and in the processes of learning and memory, such changes in GABAergic function could be an important factor in both early and later stages of AD pathogenesis. Given the limited scope of currently available therapies in modifying the course of the disease, a better understanding of GABAergic remodeling in AD could open up innovative and novel therapeutic opportunities.

Benzodiazepine Use Attenuates Cortical β-Amyloid and is Not Associated with Progressive Cognitive Decline in Nondemented Elderly Adults: A Pilot Study Using F18-Florbetapir Positron Emission Tomography

OBJECTIVE

It is inconclusive as to whether benzodiazepines (BZDs) are related to cognitive deterioration in the elderly populations. Animal studies suggest that γ-aminobutyric acid A receptor agonists, such as BZDs, may prevent Aβ-neurotoxicity and reduce β-amyloid (Aβ). However, no studies have investigated the effects of BZD use on Aβ in humans.

METHODS

This cross-sectional, prospective study using Alzheimer's Disease Neuroimaging Initiative sites in the United States and Canada on nondemented elderly adults between 55 and 90 years of age assessed cortical Aβ levels by positron emission tomography radiotracer F¹⁸-Florbetapir. Changes in global cognitive function and verbal memory performance over 2 years were assessed using scores on Montreal Cognitive Assessment and five domains of Rey Auditory Verbal Learning Test, respectively.

RESULTS

Previous BZD users (N = 15) had lower cortical Aβ levels in frontal (F(1, 26) = 8.82, p = 0.006), cingulate (F(1, 26) = 8.58, p = 0.007), parietal (F(1, 26) = 7.31, p = 0.012), and temporal (F(1, 26) = 7.67, p = 0.010) regions compared with matched BZD nonusers (N = 15), after controlling for history of psychiatric disorders and antidepressant use. Also, no differences were found in global cognitive function and changes in cortical Aβ over 2 years between continuous BZD users (N = 15) andthe matched nonuser group (N = 15).

CONCLUSION

Previous BZD use was associated with lower cortical Aβ levels in nondemented elderly control subjects. Future studies with larger samples are required to replicate our findings.

The Benzodiazepine-Dementia Disorders Link: Current State of Knowledge

The short-term effects of benzodiazepines on memory are well established and are suspected in the long term. Eleven studies have been published so far concerning benzodiazepine use and the risk of dementia disorders; nine of these studies concluded these drugs have a deleterious effect, one found a protective effect, and one (the most recently published) observed no effect. The positive association found in some studies could be due to a reverse causation bias since the main indications for benzodiazepines (e.g. sleep disorders, anxiety) can also be prodromes of dementia disorders. This bias is less likely for treatments started more than 10 years before the diagnosis. Among others, three mechanisms could underlie the potential influence of benzodiazepines on the development of dementia disorders. First, benzodiazepines can decrease beta-site amyloid precursor protein-cleaving enzyme 1 (BACE-1) and γ-secretase activity and slow down the accumulation of Aβ oligomers in the brain. This potential positive effect has never been confirmed; the same is true for the prevention of excitotoxicity through benzodiazepine anti-glutamatergic action. Second, since astrocytes located in the area of amyloid plaques could have gamma-aminobutyric acid (GABA)-secreting activity, patients with pre-dementia lesions could be at increased risk of presenting with more pronounced deleterious cognitive effects of benzodiazepines. Finally, owing to the neural compensation and cognitive reserve concepts, some subjects could cope with initial lesions by using/developing alternative networks. By lowering the brain activation level, benzodiazepines could limit this capacity. In conclusion, it is essential that animal studies explore the mechanistic hypotheses of this association found by most of the pharmacoepidemiological studies conducted on this topic.

Benzodiazepine, psychotropic medication, and dementia: A population-based cohort study

INTRODUCTION

Benzodiazepine use has been associated with increased risk of dementia. However, it remains unclear whether the risk relates to short or long half-life benzodiazepines and whether it extends to other psychotropic drugs.

METHODS

Prospective cohort study among 8240 individuals ≥65, interviewed on medication use. Incident dementia confirmed by an end point committee after a multistep procedure.

RESULTS

During a mean of 8 years of follow-up, 830 incident dementia cases were observed. Users of benzodiazepines at baseline had a 10% increased risk of dementia (adjusted hazard ratio [HR], 1.10; 95% confidence interval, 0.90-1.34). However, long half-life (>20 hours) benzodiazepine users had a marked increased risk of dementia (HR = 1.62; 1.11-2.37) compared with short half-life users (HR = 1.05; 0.85-1.30). Users of psychotropics had an increased risk of dementia (HR = 1.47; 1.16-1.86).

DISCUSSION

Results of this large, prospective study show increased risk of dementia for long half-life benzodiazepine and psychotropic use.

Impact of alprazolam in allostatic load and neurocognition of patients with anxiety disorders and chronic stress (GEMA): observational study protocol

INTRODUCTION

The allostatic load model explains the additive effects of multiple biological processes that accelerate pathophysiology related to stress, particularly in the central nervous system. Stress-related mental conditions such as anxiety disorders and neuroticism (a well-known stress vulnerability factor), have been linked to disturbances of hypothalamo-pituitary-adrenal with cognitive implications. Nevertheless, there are controversial results in the literature and there is a need to determine the impact of the psychopharmacological treatment on allostatic load parameters and in cognitive functions. Gador study of Estres Modulation by Alprazolam, aims to determine the impact of medication on neurobiochemical variables related to chronic stress, metabolic syndrome, neurocognition and quality of life in patients with anxiety, allostatic load and neuroticism.

METHODS/ANALYSIS

In this observational prospective phase IV study, highly sympthomatic patients with anxiety disorders (six or more points in the Hamilton-A scale), neuroticism (more than 18 points in the Neo five personality factor inventory (NEO-FFI) scale), an allostatic load (three positive clinical or biochemical items at Crimmins and Seeman criteria) will be included. Clinical variables of anxiety, neuroticism, allostatic load, neurobiochemical studies, neurocognition and quality of life will be determined prior and periodically (1, 2, 4, 8, and 12 weeks) after treatment (on demand of alprazolam from 0.75 mg/day to 3.0 mg/day). A sample of n=55/182 patients will be considered enough to detect variables higher than 25% (pretreatment vs post-treatment or significant correlations) with a 1-ß power of 0-80. t Test and/or non-parametric test, and Pearson's test for correlation analysis will be determined.

ETHICS AND DISSEMINATION

This study protocol was approved by an Independent Ethics Committee of FEFyM (Foundation for Pharmacological Studies and Drugs, Buenos Aires) and by regulatory authorities of Argentina (ANMAT, Dossier # 61 409-8 of 20 April 2009), following the law of Habeas Data and psychotherapeutic drug control.

TRIAL REGISTRATION NUMBER

GEMA 20811.

Association between Benzodiazepine Use and Dementia: A Meta-Analysis

BACKGROUND

The association between long-term benzodiazepine use and risk of dementia remains controversial. Therefore, current study aimed to quantify this association, and to explore a potential dose-response pattern.

METHODS

We searched PubMed, Embase and the Cochrane Library through August 17, 2014. We included nested case-control or prospective cohort studies that provided risk estimates on the association of benzodiazepine use with risk of dementia, and a clear definition of status of benzodiazepine use. Overall effect size was calculated using a random-effects model.

FINDINGS

Six studies were eligible for inclusion, involving 11,891 dementia cases and 45,391 participants. Compared with never users, pooled adjusted risk ratios (RRs) for dementia were 1.49 (95% confidence interval (CI) 1.30-1.72) for ever users, 1.55 (95% CI 1.31-1.83) for recent users, and 1.55 (95% CI 1.17-2.03) for past users. The risk of dementia increased by 22% for every additional 20 defined daily dose per year (RR, 1.22, 95%CI 1.18-1.25). When we restricted our meta-analyses to unadjusted RRs, all initial significant associations persisted.

CONCLUSIONS

Long-term benzodiazepine users have an increased risk of dementia compared with never users. However, findings from our study should be treated with caution due to limited studies and potential reverse causation. Large prospective cohort studies with long follow-up duration are warranted to confirm these findings.

Bridging the gap between education and appropriate use of benzodiazepines in psychiatric clinical practice

More than half a century after their discovery, benzodiazepines (BDZs) still represent one of the largest and most widely prescribed groups of psychotropic compounds, not only in clinical psychiatry but also in the entire medical field. Over the last two decades, however, there has been an increased focus on the development of antidepressants and antipsychotics on the part of the pharmaceutical industry, clinicians, and researchers, with a reduced interest in BDZs, in spite of their widespread clinical use. As a consequence, many psychiatric residents, medical students, nurses, and other mental health professionals might receive poor academic teaching and training regarding these agents, and have the false impression that BDZs represent an outdated chapter in clinical psychopharmacology. However, recent advances in the field, including findings concerning epidemiology, addiction risk, and drug interactions, as well as the introduction of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition with related diagnostic changes, strongly encourage an updated appraisal of the use of BDZs in clinical practice. During a recent thematic event convened with the aim of approaching this topic in a critical manner, a group of young Italian psychiatrists attempted to highlight possible flaws in current teaching pathways, identify the main clinical pros and cons regarding current use of BDZs in clinical practice, and provide an updated overview of their use across specific clinical areas and patient populations. The main results are presented and discussed in this review.

Benzodiazepine use and risk of Alzheimer's disease: case-control study

OBJECTIVES

To investigate the relation between the risk of Alzheimer's disease and exposure to benzodiazepines started at least five years before, considering both the dose-response relation and prodromes (anxiety, depression, insomnia) possibly linked with treatment.

DESIGN

Case-control study.

SETTING

The Quebec health insurance program database (RAMQ).

PARTICIPANTS

1796 people with a first diagnosis of Alzheimer's disease and followed up for at least six years before were matched with 7184 controls on sex, age group, and duration of follow-up. Both groups were randomly sampled from older people (age >66) living in the community in 2000-09.

MAIN OUTCOME MEASURE

The association between Alzheimer's disease and benzodiazepine use started at least five years before diagnosis was assessed by using multivariable conditional logistic regression. Ever exposure to benzodiazepines was first considered and then categorised according to the cumulative dose expressed as prescribed daily doses (1-90, 91-180, >180) and the drug elimination half life.

RESULTS

Benzodiazepine ever use was associated with an increased risk of Alzheimer's disease (adjusted odds ratio 1.51, 95% confidence interval 1.36 to 1.69; further adjustment on anxiety, depression, and insomnia did not markedly alter this result: 1.43, 1.28 to 1.60). No association was found for a cumulative dose <91 prescribed daily doses. The strength of association increased with exposure density (1.32 (1.01 to 1.74) for 91-180 prescribed daily doses and 1.84 (1.62 to 2.08) for >180 prescribed daily doses) and with the drug half life (1.43 (1.27 to 1.61) for short acting drugs and 1.70 (1.46 to 1.98) for long acting ones).

CONCLUSION

Benzodiazepine use is associated with an increased risk of Alzheimer's disease. The stronger association observed for long term exposures reinforces the suspicion of a possible direct association, even if benzodiazepine use might also be an early marker of a condition associated with an increased risk of dementia. Unwarranted long term use of these drugs should be considered as a public health concern.

Chronic use of benzodiazepines and latent cognitive decline in the elderly: results from the Three-city study

We aimed to examine whether long-term use of benzodiazepines is associated with an accelerated decline of cognitive performances by using a statistical model specifically adapted to multivariate longitudinal bounded quantitative outcomes. The data came from the "Three-city" study, a French population based study. All the subjects were 65 years old or older at inclusion and had been followed-up for 7 years. The use of benzodiazepines and cognitive functioning were assessed at each examination phase (baseline, 2, 4 and 7 years). Cognitive decline was analyzed using a nonlinear multivariate mixed model with a latent process. This model makes it possible to assess change over time of the latent cognitive process underlying several neuropsychological tests: Mini Mental Status Examination, Isaacs Set test, Benton Visual Retention Test, and Trail Making Test (A and B), and to describe and account for their metrological properties. Analyses were adjusted for age, center, gender, education, socio-professional status, depression, insomnia, high blood pressure, hypercholesterolemia, alcohol, tobacco consumption and physical activity. Nine hundred and sixty nine subjects who reported taking benzodiazepines for 2, 4 or 7 consecutive years were compared to 4226 subjects who were non-benzodiazepine users. Chronic use of benzodiazepine was significantly associated with a lower latent cognitive level (β=-1.79 SE=0.25 p=<0.001), but no association was found between chronic use and an acceleration of cognitive decline, neither on the latent cognitive process (β × time=0.010 SE=0.04 p=0.81), nor on specific neuropsychological tests. Our results suggest that chronic benzodiazepine use is associated with poorer cognitive performance but not with accelerated cognitive decline with age.

Risk of dementia in patients with insomnia and long-term use of hypnotics: a population-based retrospective cohort study

BACKGROUND

Hypnotics have been reported to be associated with dementia. However, the relationship between insomnia, hypnotics and dementia is still controversial. We sought to examine the risk of dementia in patients with long-term insomnia and the contribution of hypnotics.

METHODS

Data was collected from Taiwan's Longitudinal Health Insurance Database. The study cohort comprised all patients aged 50 years or older with a first diagnosis of insomnia from 2002 to 2007. The comparison cohort consisted of randomly selected patients matched by age and gender. Each patient was individually tracked for 3 years from their insomnia index date to identify whether the patient had a first diagnosis of dementia. Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

We identified 5693 subjects with long-term insomnia and 28,465 individuals without. After adjusting for hypertension, diabetes mellitus, hyperlipidemia, and stroke, those with long-term insomnia had significantly higher risks of dementia (HR, 2.34; 95% CI, 1.92-2.85). Patients with long-term insomnia and aged 50 to 65 years had a higher increased risk of dementia (HR, 5.22; 95% CI, 2.62-10.41) than those older than 65 years (HR, 2.33; 95% CI, 1.90-2.88). The use of hypnotics with a longer half-life and at a higher prescribed dose predicted a greater increased risk of dementia.

CONCLUSIONS

Patients with long-term use of hypnotics have more than a 2-fold increased risk of dementia, especially those aged 50 to 65 years. In addition, the dosage and half-lives of the hypnotics used should be considered, because greater exposure to these medications leads to a higher risk of developing dementia.

Benzodiazepine use and risk of dementia: prospective population based study

OBJECTIVE

To evaluate the association between use of benzodiazepines and incident dementia.

DESIGN

Prospective, population based study.

SETTING

PAQUID study, France.

PARTICIPANTS

1063 men and women (mean age 78.2 years) who were free of dementia and did not start taking benzodiazepines until at least the third year of follow-up.

MAIN OUTCOME MEASURES

Incident dementia, confirmed by a neurologist.

RESULTS

During a 15 year follow-up, 253 incident cases of dementia were confirmed. New use of benzodiazepines was associated with an increased risk of dementia (multivariable adjusted hazard ratio 1.60, 95% confidence interval 1.08 to 2.38). Sensitivity analysis considering the existence of depressive symptoms showed a similar association (hazard ratio 1.62, 1.08 to 2.43). A secondary analysis pooled cohorts of participants who started benzodiazepines during follow-up and evaluated the association with incident dementia. The pooled hazard ratio across the five cohorts of new benzodiazepine users was 1.46 (1.10 to 1.94). Results of a complementary nested case-control study showed that ever use of benzodiazepines was associated with an approximately 50% increase in the risk of dementia (adjusted odds ratio 1.55, 1.24 to 1.95) compared with never users. The results were similar in past users (odds ratio 1.56, 1.23 to 1.98) and recent users (1.48, 0.83 to 2.63) but reached significance only for past users.

CONCLUSIONS

In this prospective population based study, new use of benzodiazepines was associated with increased risk of dementia. The result was robust in pooled analyses across cohorts of new users of benzodiazepines throughout the study and in a complementary case-control study. Considering the extent to which benzodiazepines are prescribed and the number of potential adverse effects of this drug class in the general population, indiscriminate widespread use should be cautioned against.

Prevalence of psychiatric disorders in community-dwelling older men and women with cognitive impairment no dementia: results from the ESA study

OBJECTIVES

To assess the prevalence rate of mood disorders, anxiety disorders, benzodiazepine dependence, and insomnia in older men and women with probable cognitive impairment no dementia (CIND) and to examine the independent associations between each disorder and CIND.

METHOD

Participants were a random sample of community-dwelling individuals aged 65-96 (N = 2414). Semi-structured in-home interviews based on DSM-IV-TR (DSM, Diagnostic and Statistical Manual of Mental Disorders) criteria evaluated the prevalence rates of mood disorders, anxiety disorders, benzodiazepine dependence, and insomnia. Participants were classified as probable CIND based on their Mini-Mental State Examination score using sex, age, and education-stratified cut-offs (lower than the 15th percentile).

RESULTS

In men, 22.7% of individuals with probable CIND and 12.1% of those with normal cognition had at least one psychiatric disorder (crude odds ratio (OR): 2.13, 95% confidence interval (CI): 1.23-3.69). More specifically, mood disorders (3.43, 1.74-6.75), benzodiazepine dependence (5.10, 1.23-21.11), and comorbid anxiety and mood disorders (8.67, 2.00-37.68) were significantly associated with probable CIND, but not anxiety disorders alone and insomnia. The prevalence rate of psychiatric disorders was similar in women with probable CIND (23.1%) and in women without CIND (23.9%; 0.95, 0.64-1.42). No specific psychiatric disorder was significantly associated with probable CIND in women. All associations remained unchanged after adjustments for potential confounders.

CONCLUSIONS

The association between psychiatric disorders and probable CIND appears to be sex-specific. In clinical practice, mood disorders, and benzodiazepine dependence should receive particular attention since these disorders are associated with a condition increasing the risk of dementia.

Sedative use and incident cognitive decline among persons aged 75 years and older: a population-based longitudinal study

BACKGROUND

Acute exposure to sedative drugs may induce memory impairment, but there is mixed evidence that long-term sedative use may result in incident cognitive decline. The objective of this study was to investigate the use of sedative drugs and incident cognitive decline in a population-based sample of persons aged 75 years and older.

METHODS

The study sample comprised 781 participants in the Geriatric Multidisciplinary Strategy for the Good Care of the Elderly (GeMS) study in Kuopio, Finland. Data on health status, drug use, and sociodemographic factors were elicited during annual nurse interviews from 2004 to 2007. A linear mixed model was used to compare change in Mini-Mental State Examination (MMSE) scores (2005-2007) among users of sedative drugs in 2004 and 2005 (n = 139) to non-users of sedative drugs from 2004 to 2007 (n = 310). The model was adjusted for covariates including age, gender, education, depressive symptoms and antipsychotic use.

RESULTS

Unadjusted mean MMSE scores were 27.50 in 2005, 26.58 in 2006, and 25.95 in 2007 among users of sedative drugs. Unadjusted mean MMSE scores were 28.05 in 2005, 27.61 in 2006, and 27.09 in 2007 among non-users of sedative drugs. Adjusted mean MMSE scores were 0.31 points lower in 2005, 0.62 points lower in 2006, and 0.93 lower in 2007 among users compared to non-users of sedative drugs (P = 0.051).

CONCLUSIONS

Sedatives were not associated with statistically significant cognitive decline. However, clinicians should maintain a judicious approach to prescribing sedative drugs given the risk of adverse drug events.

Use of CNS medications and cognitive decline in the aged: a longitudinal population-based study

Background

Previous studies have found associations between the use of central nervous system medication and the risk of cognitive decline in the aged. Our aim was to assess whether the use of a single central nervous system (CNS) medication and, on the other hand, the combined use of multiple CNS medications over time are related to the risk of cognitive decline in an older (≥ 65 yrs) population that is cognitively intact at baseline.

Methods

We conducted a longitudinal population-based study of cognitively intact older adults. The participants were 65 years old or older and had Mini-Mental State Examination (MMSE) sum scores of 24 points or higher. The study included a 7.6-year follow-up. The use of benzodiazepines and related drugs (BZDs), antipsychotics (APs), antidepressants (ADs), opioids (Ops), anticholinergics (AChs) and antiepileptics (AEs) was determined at baseline and after a 7.6-years of the follow-up period. Cognitive functioning was used as an outcome variable measured with MMSE at baseline and at the mean follow-up of 7.6 years. Control variables were adjusted with analyses of covariance.

Results

After adjusting for control variables, the use of Ops and the concomitant use of Ops and BZDs as well as the use of Ops and any CNS medication were associated with cognitive decline. The use of AChs was associated with decline in cognitive functioning only in men.

Conclusions

Of all the CNS medications analyzed in this study, the use of Ops may have the greatest effect on cognitive functioning in the ageing population. Due to small sample sizes these findings cannot be generalized to the unselected ageing population. More studies are needed concerning the long-term use of CNS medications, especially their concomitant use, and their potential cognitive effects.

Pharmacoepidemiology of psychotropic drugs: examples of current research challenges on major public health issues

Background– As a large number of persons are exposed to prescribed psychotropic drugs, their utilisation and impact should be further explored at the population level.Aims– To illustrate the interest of pharmacoepidemiological studies of psychotropic drugs by selected examples of major public health issues.Method– Selective review of the literature. Results – Many questions remain unsolved regarding the behavioural teratogenicity of prenatal exposure to psychotropic drugs, the impact of their increasing use in children, the long-term cognitive consequences of exposure to benzodiazepines, and the risks associated with extension of indications of antipsychotic drugs.Conclusion– Pharmacoepidemiological studies need to be further developed owing to the large number of public health questions raised by the extensive and expanding use of psychotropic drugs.

The association between dementia and long-term use of benzodiazepine in the elderly: nested case-control study using claims data

OBJECTIVES

The aim of this study was to examine the association between long-term benzodiazepines (BZDs) use and the risk of dementia.

DESIGN

Population-based nested case-control study of dementia.

SETTING

All subjects were aged 45 and older and enrolled in the National Health Insurance Research Database in Taiwan, 1997-2004.

PARTICIPANTS

Cases (N = 779) were patients who were identified with dementia at least two times in their outpatient claims. They were individually matched to six comparison subjects (N = 4,626) based on age and gender.

MEASUREMENTS

BZD usage (average dosage per year, average days per year, and cumulative dose and periods) and potential confounding comobidities, including cardiovascular and psychiatric diseases.

RESULTS

Subjects with dementia had higher cumulative dose, longer duration of BZDs exposure, and more likelihood to be long-term BZDs users.

CONCLUSION

Our findings suggest that long-term use of BZDs is associated with an increased risk for dementia, but the underlying mechanisms remain unclear, and further investigations are needed. Long-term use of BZDs should be avoided among the elderly, who may be at a higher risk for developing dementia, in addition to other health problems.

An immunohistochemical study of GABA A receptor gamma subunits in Alzheimer's disease hippocampus: relationship to neurofibrillary tangle progression

Immunohistochemical characterization of the distribution of GABA(A) receptor subunits gamma1/3 and 2 in the hippocampus relative to neurofibrillary tangle (NFT) pathology staging was performed in cognitively normal subjects (Braak stage I/II, n = 4) and two groups of Alzheimer's disease (AD) patients (Braak stage III/IV, n = 4; Braak stage V/VI, n = 8). In both Braak groups of AD patients, neuronal gamma1/3 and gamma2 immunoreactivity was preserved in all hippocampal subfields. However, compared to normal controls neuronal gamma1/3 immunoreactivity was more intense in several end-stage AD subjects. Despite increased NFT pathology in the Braak V/VI AD group, GABA(A)gamma1/3 and gamma2 immunoreactivity did not co-localize with markers of NFT. These results suggest that upregulating or preserving GABA(A)gamma1/3 and gamma2 receptors may protect neurons against neurofibrillary pathology in AD.