The neurobiology of neuropsychiatric syndromes in dementia

The impact of education level and socioeconomic status on the association between depressive symptoms and memory in an older population in Latin America: An exploratory analysis from the Brazilian Longitudinal Study of Aging (ELSI-BRAZIL)

Purpose

The globally increasing older population raises concerns about age-related conditions, including cognitive impairment and depressive symptoms. In Latin America, nearly one-third of the population is affected by either of these conditions. However, data investigating the association between cognitive impairment and depressive symptoms, particularly in Brazil, are limited to small-scale studies that have not carefully examined the critical effects of variables such as education level and socioeconomic status on this relationship. We aimed at exploring this association in a representative population-based cohort.

Methods

We used the Brazilian Longitudinal Study of Aging (ELSI-BRAZIL) database to examine the relationship between depressive symptoms and cognitive impairment in Brazilian older adults, adjusted for potential confounders. Direct acyclic graphs and multivariable linear regression were used to build our model. Depressive symptoms were measured using a short version of the Center for Epidemiologic Studies Scale (CES D-8), and combined memory recall test as a surrogate of cognitive impairment.

Results

The study included 8280 participants. Only education level was identified as a confounder for the relationship between memory loss and depressive symptoms. After adjusting for age, sex, and education level, there was strong evidence for a negative association between depressive symptoms and memory performance. For every 5-unit increase in the CES D-8 score, there was a reduction in memory capacity, translating to a loss of approximately one word in the combined words recall test (mean - 0.18, 95% CI -0.22; -0.15, P < 0.001). In addition, we found strong evidence for an interaction between socioeconomic status and depressive symptoms. Subjects belonging to medium socioeconomic status (SES) showed more pronounced memory decline, when compared to those with lower SES (mean - 0.28, 95% CI -0.42 to -0.14, P < 0.001).

Conclusions

In adults aged over 50, after adjusting for sex, age, and educational level, a 5-unit increase in CES D-8 score is associated with loss of one point in the combined memory recall test. This association seems to be confounded by educational level and significantly modified by socioeconomic status.

Sex-specific in the association between depressive symptoms and risk of cognitive impairment in Chinese older adults

BACKGROUND

Many studies have focused on the relationship between depressive symptoms and cognitive impairment, but gender differences in this relationship are unclear, especially among Chinese older adults. Therefore, this study explores whether there are gender differences between depressive symptoms and risk of cognitive impairment based on a survey of a Chinese older adult population.

STUDY DESIGN

This is a cross-sectional study.

METHOD

We screened 9678 older adults aged 65 to 105 from the 2018 CLHLS database. The 10-item Center for Epidemiological Studies Depression Scale (CESD-10) and Mini-Mental State Examination (MMSE) were utilized for measuring depressive symptoms and cognitive performance, respectively. Logistic regressions and restricted cubic spline were applied to investigate the relationship between depressive symptoms and cognitive impairment.

RESULTS

Of the 9678 participants, 4719 (48.8 %) were men. The association between severe depressive symptoms and cognitive impairment was more pronounced in older men (male × severe depressive symptoms: OR = 2.71, 95%CI = 1.07-6.92, p = 0.037). Compared with no depressive symptoms, severe depressive symptoms were associated with an almost five times greater risk of cognitive impairment in men (OR = 4.84, 95 % CI = 2.26-10.40, p < 0.001, compared to OR = 2.25, 95 % CI = 1.27-3.96, p = 0.005 in women). Gender differences were demonstrated in the association of individual ten depressive symptoms with cognitive impairment: men who felt lonely were more likely to have cognitive impairment (OR = 1.24, 95 % CI = 1.06-1.47, p = 0.010), while women who slept poorly were more likely to have cognitive impairment (OR = 1.42, 95 % CI = 1.16-1.74, p = 0.001).

CONCLUSION

Results indicate a stronger association between severe depressive symptoms and cognitive impairment among older Chinese males. Our study suggests that reducing loneliness can help prevent cognitive impairment in older men, and improving sleep quality can help improve cognitive function in older women.

Ascorbate insufficiency disrupts glutamatergic signaling and alters electroencephalogram phenotypes in a mouse model of Alzheimer's disease

Clinical studies have reported that increased epileptiform and subclinical epileptiform activity can be detected in many patients with an Alzheimer's disease (AD) diagnosis using electroencephalogram (EEG) and this may correlate with poorer cognition. Ascorbate may have a specific role as a neuromodulator in AD as it is released concomitantly with glutamate reuptake following excitatory neurotransmission. Insufficiency may therefore result in an exacerbated excitatory/inhibitory imbalance in neuronal signaling. Using a mouse model of AD that requires dietary ascorbate (Gulo-/-APPswe/PSEN1dE9), EEG was recorded at baseline and during 4 weeks of ascorbate depletion in young (5-month-old) and aged (20-month-old) animals. Data were scored for changes in quantity of spike trains, individual spikes, sleep-wake rhythms, sleep fragmentation, and brainwave power bands during light periods each week. We found an early increase in neuronal spike discharges with age and following ascorbate depletion in AD model mice and not controls, which did not correlate with brain amyloid load. Our data also show more sleep fragmentation with age and with ascorbate depletion. Additionally, changes in brain wave activity were observed within different vigilance states in both young and aged mice, where Gulo-/-APPswe/PSEN1dE9 mice had shifts towards higher frequency bands (alpha, beta, and gamma) and ascorbate depletion resulted in shifts towards lower frequency bands (delta and theta). Microarray data supported ascorbate insufficiency altering glutamatergic transmission through the decreased expression of glutamate related genes, however no changes in protein expression of glutamate reuptake transporters were observed. These data suggest that maintaining optimal brain ascorbate levels may support normal brain electrical activity and sleep patterns, particularly in AD patient populations where disruptions are observed.

NREM sleep loss increases neurofilament light chain levels in APP/PS1 and C57BL/6 J mice

PURPOSE

Sleep disturbances exacerbate the progression of Alzheimer's disease (AD), but disturbances of non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep may have different effects. Neurofilament light chain (NfL), an axon-specific protein, is an indicator of the severity of neuronal apoptosis. To investigate whether or not NREM or REM sleep is crucial to neuronal survival, we examined the effects of induced NREM or REM sleep loss on NfL levels in APP/PS1 mice, a model of AD, and their wild-type (WT) C57BL/6 J littermates.

METHODS

At 6 months of age, WT mice and AD mice were equally divided into six groups, namely, the WT-normal sleep (S), WT-total sleep deprivation (TSD), WT-REM deprivation (RD), AD-S, AD-TSD and AD-RD groups, according to the type of sleep intervention applied. All mice underwent 6 days of sleep intervention. Cerebrospinal fluid (CSF) and plasma NfL levels were measured at baseline and on days 2, 4 and 6, and spatial memory was assessed in the Morris water maze (MWM) test.

RESULTS

Among the 18 WT and 18 AD mice, CSF and plasma NfL levels were higher in AD-TSD mice than in AD-S or AD-RD mice, while no significant difference was observed between the latter two groups. In AD-TSD mice, CSF and plasma NfL levels increased with the duration of sleep deprivation. A similar pattern of results was observed for the WT groups.

CONCLUSIONS

NREM sleep loss may increase CSF and plasma NfL levels in both WT and AD mice.

Association between depression status in adolescents and cognitive performance over the subsequent six years: A longitudinal study

BACKGROUND

Adolescent depression is a common mental health problem and is sometimes associated with cognitive impairments. However, existing research regarding the association between depression status in adolescents and cognitive performance over the subsequent years is relatively paucity.

METHODS

The present study used longitudinal data from four waves (2012, 2014, 2016, and 2018) of the China Family Panel Studies (CFPS) to explore the associations between adolescent depression status in 2012 and cognitive performance (measured by immediate word recall, delayed word recall, number series tests, mathematics, and vocabulary) over the subsequent years. A total of 1055 (51.72 %), 1115 (54.66 %), and 879 (43.09 %) of the 2040 adolescents identified in 2012 were followed up in 2014, 2016, and 2018, respectively.

RESULTS

We found that adolescent depression status consistently showed a negative association with cognitive performance at the measurement points over six years. The associations were retained for most cognitive outcomes after controlling for a variety of confounding factors (adolescents, parental, and family characteristics).

CONCLUSIONS

The findings of this study provide more evidence of the association between depression status in adolescents and cognitive performance. Additionally, it highlights the importance of focusing on cognitive impairment in patients with depression more broadly, especially during adolescence, a critical period for cognitive development.

The association between longitudinal changes in depressive symptoms and cognitive decline among middle-aged and older Chinese adults

OBJECTIVE

Depression is associated with cognitive impairment and dementia, but few studies have been done on Chinese adults. This study evaluates the relationship between depressive symptoms status and cognitive function in middle-aged and elderly Chinese adults.

METHODS

We included 7,968 participants from the Chinese Health and Retirement Longitudinal Survey (CHRALS) with a follow-up of 4 years. Using the Center for Epidemiological Studies Depression Scale to measure depressive symptoms, with a score of 12 or more indicating elevated depressive symptoms. Adjust covariance analysis and generalized linear analysis were used to investigate the relationship between depressive symptoms status (never, new-onset, remission and persistence) and cognitive decline. Restricted cubic spline regression was used to performed the potential nonlinear associations between depressive symptoms and the change scores of cognitive functions.

RESULTS

During the 4-year follow-up, 1148 participants (14.41%) reported persistent depressive symptoms. The participants who have persistent depressive symptoms with more declines in total cognitive scores (least-square mean = -1.99, 95% CI: -3.70 to -0.27). Compared with never depressive symptoms, participants with persistent depressive symptoms experienced a faster decline in cognitive scores (β = -0.68, 95%CI: -0.98 to -0.38), and small difference (d=0.29) at follow-up. But females with new-onset depression had more cognitive decline than those with persistent depression (least-square mean _new-onset - least-square mean _persistent=-0.10), its differences in males (least-square mean _new-onset - least-square mean _persistent=0.03).

CONCLUSIONS

Participants with persistent depressive symptoms experienced a faster decline in cognitive function, but differently in men and women.

Sleep fragmentation affects glymphatic system through the different expression of AQP4 in wild type and 5xFAD mouse models

Alzheimer's disease (AD) is characterized by genetic and multifactorial risk factors. Many studies correlate AD to sleep disorders. In this study, we performed and validated a mouse model of AD and sleep fragmentation, which properly mimics a real condition of intermittent awakening. We noticed that sleep fragmentation induces a general acceleration of AD progression in 5xFAD mice, while in wild type mice it affects cognitive behaviors in particular learning and memory. Both these events may be correlated to aquaporin-4 (AQP4) modulation, a crucial player of the glymphatic system activity. In particular, sleep fragmentation differentially affects aquaporin-4 channel (AQP4) expression according to the stage of the disease, with an up-regulation in younger animals, while such change cannot be detected in older ones. Moreover, in wild type mice sleep fragmentation affects cognitive behaviors, in particular learning and memory, by compromising the glymphatic system through the decrease of AQP4. Nevertheless, an in-depth study is needed to better understand the mechanism by which AQP4 is modulated and whether it could be considered a risk factor for the disease development in wild type mice. If our hypotheses are going to be confirmed, AQP4 modulation may represent the convergence point between AD and sleep disorder pathogenic mechanisms.

Transcranial magnetic stimulation for sleep disorders in Alzheimer's disease: A double-blind, randomized, and sham-controlled pilot study

BACKGROUND

Sleep disorders are commonly comorbid with Alzheimer's disease (AD), And these disorders interfere with each other in many aspects. To date, pharmacological treatments for sleep disorders are still limited, and studies investigating repetitive transcranial magnetic stimulation (rTMS) for sleep disorders in AD are still lacking.

METHOD

A single-center, randomized, double-blind, parallel-arm, and sham-controlled pilot study was conducted in AD patients with sleep disorders. Seventy subjects were randomly divided into the following two groups: the sham group (SG) and the intervention group (IG). We evaluated sleep changes using the Pittsburgh Sleep Quality Index (PSQI) before and after the intervention. We also assessed the patients' cognitive function by the Alzheimer's Disease Assessment Scale-Cognitive section (ADAS-Cog). The intervention period was four weeks, and the patients were followed up in the 8th week to test the persistence of the effect of the rTMS intervention.

RESULT

Significant differences in the PSQI scores were found between the SG and IG at the end of the 4-week intervention (P = 0.001) and the 8-week follow-up (P < 0.001). There was also significant improvement in ADAS-Cog scores (4 weeks: P = 0.048, 8 weeks: P = 0.038). Activities of daily living (ADL) did not significantly differ between the SG and IG.

CONCLUSION

rTMS can effectively ameliorate sleep disorders in AD patients.

Trajectories of depressive symptoms and associated patterns of cognitive decline

The aim was to investigate the pattern and rate of cognitive decline across distinctive trajectories of depressive symptoms in older adults. In this prospective multinational cohort study on 69,066 participants (on average 64 years at baseline, 55% women), assessments of cognitive functions (immediate recall, delayed recall, verbal fluency) and depressive symptoms (EURO-D scale) were conducted at 2-year intervals. The trajectories of depressive symptoms were obtained using latent growth mixture modelling, cognitive decline was assessed using smoothing splines and linear mixed effects models. Four distinct trajectories of depressive symptoms were identified: constantly low (n = 49,660), constantly high (n = 2999), increasing (n = 6828) and decreasing (n = 9579). Individuals with increasing and constantly high depressive symptoms showed linear cognitive decline, while those with constantly low and decreasing depressive symptoms had fluctuating cognition. Participants with increasing depressive symptoms had the fastest decline, while those with decreasing symptoms were spared from decline in cognition. This study suggests that the pattern as well as the rate of cognitive decline co-occurs with specific patterns of changes in depressive symptoms over time. The most pronounced cognitive decline is present in individuals, in whom depressive symptoms increase late in life. Unique mechanisms of cognitive decline may exist for subgroups of the population, and are associated with the trajectory of depressive symptoms.

Effects of exercise on sleep in neurodegenerative disease

As the population ages, the incidence and prevalence of neurodegenerative disorders will continue to increase. Persons with neurodegenerative disease frequently experience sleep disorders, which not only affect quality of life, but potentially accelerate progression of the disease. Unfortunately, pharmacological interventions are often futile or have adverse effects. Therefore, investigation of non-pharmacological interventions has the potential to expand the treatment landscape for these disorders. The last decade has observed increasing recognition of the beneficial role of exercise in brain diseases, and neurodegenerative disorders in particular. In this review, we will focus on the therapeutic role of exercise for sleep dysfunction in four neurodegenerative diseases, namely Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. Available data suggest that exercise may have the potential to improve sleep disorders and attenuate neurodegeneration, particularly in Alzheimer's disease and Parkinson's disease. However, additional research is required in order to understand the most effective exercise therapy for these indications; the best way to monitor the response to interventions; the influence of exercise on sleep dysfunction in Huntington's disease and amyotrophic lateral sclerosis; and the mechanisms underlying exercise-induced sleep modifications.

Clinical Aspects of Neurobehavioral Symptoms of Dementia

Neurobehavioral symptoms of dementia (NBSD) are very common and are significant symptoms of the illness, contributing most to caregiver burdens and often resulting in premature institutionalization of the person with dementia. The main symptoms of NBSD are anxiety, depression, delusions, and hallucinations. NBSD produce significant problems for both patients and caregivers. The pathophysiology of NBSD is determined by genetic, structural, or environmental factors. Therefore, treatment of NBSD requires continuous and organic cooperation between patients, caregivers, social environments, and doctors. Therefore, it is important for neurologists, who mainly view NBSD for dementia patients, to increase their understanding of these more comprehensive areas as well as the latest insights and treatments to help patients and caregivers.

Sleep architecture changes in the APP23 mouse model manifest at onset of cognitive deficits

Alzheimer's disease (AD), which accounts for most of the dementia cases, is, aside from cognitive deterioration, often characterized by the presence of non-cognitive symptoms such as activity and sleep disturbances. AD patients typically experience increased sleep fragmentation, excessive daytime sleepiness and night-time insomnia. Here, we sought to investigate the link between sleep architecture, cognition and amyloid pathology in the APP23 amyloidosis mouse model for AD. By means of polysomnographic recordings the sleep-wake cycle of freely-moving APP23 and wild-type (WT) littermates of 3, 6 and 12 months of age was examined. In addition, ambulatory cage activity was assessed by interruption of infrared beams surrounding the home cage. To assess visuo-spatial learning and memory a hidden-platform Morris-type Water Maze (MWM) experiment was performed. We found that sleep architecture is only slightly altered at early stages of pathology, but significantly deteriorates from 12 months of age, when amyloid plaques become diffusely present. APP23 mice of 12 months old had quantitative reductions of NREM and REM sleep and were more awake during the dark phase compared to WT littermates. These findings were confirmed by increased ambulatory cage activity during that phase of the light-dark cycle. No quantitative differences in sleep parameters were observed during the light phase. However, during this light phase, the sleep pattern of APP23 mice was more fragmented from 6 months of age, the point at which also cognitive abilities started to be affected in the MWM. Sleep time also positively correlated with MWM performance. We also found that spectral components in the EEG started to alter at the age of 6 months. To conclude, our results indicate that sleep architectural changes arise around the time the first amyloid plaques start to form and cognitive deterioration becomes apparent. These changes start subtle, but gradually worsen with age, adequately mimicking the clinical condition.

Therapeutic efficacy of the Ginkgo special extract EGb761® within the framework of the mitochondrial cascade hypothesis of Alzheimer's disease

OBJECTIVES

The mitochondrial cascade hypothesis of dementia assumes mitochondrial dysfunction as an important common pathomechanism for the whole spectrum of age-associated memory disorders from cognitive symptoms in the elderly over mild cognitive impairment to Alzheimer's dementia. Thus, a drug such as the Ginkgo special extract EGb 761^® which improves mitochondrial function should be able to ameliorate cognitive deficits over the whole aging spectrum.

METHODS

We review the most relevant publications about effects of EGb 761^® on cognition and synaptic deficits in preclinical studies as well as on cognitive deficits in man from aging to dementia.

RESULTS

EGb 761^® improves mitochondrial dysfunction and cognitive impairment over the whole spectrum of age-associated cognitive disorders in relevant animal models and in vitro experiments, and also shows clinical efficacy in improving cognition over the whole range from aging to Alzheimer's or even vascular dementia.

CONCLUSIONS

EGb 761^® shows clinical efficacy in the treatment of cognitive deficits over the whole spectrum of age-associated memory disorders. Thus, EGb 761^® can serve as an important pharmacological argument for the mitochondrial cascade hypothesis of dementia.

Mitochondrial Pharmacology of Dimebon (Latrepirdine) Calls for a New Look at its Possible Therapeutic Potential in Alzheimer's Disease

Dimebon (latrepirdine), an old antihistaminic drug, showed divergent results in two large clinical trials in Alzheimer disease (AD), which according to our review might be related to the specific pharmacological properties of the drug and the different patient populations included in both studies. Out of the many pharmacological effects of Dimebon, improvement of impaired mitochondrial function seeems to be most relevant for the substantial effects on cognition and behaviour reported in one of the studies, as these effects are already present at the low concentrations of dimebon measured in plasma and tissues of patients and experimental animals. Since impaired mitochondrial function seems to be the major driving force for the progression of the clinical symptoms and since most of the clinical benefits of dimebon originate from an effect on the symptomatic deterioration, mitochondrial improvement can also explain the lack of efficacy of this drug in another clinical trial where symptoms of the patiets remained stable for the time of the study. Accordingly, it seems worthwhile to reevaluate the clinical data to proof that clinical response is correlated with high levels of Neuropsychiatric Symptoms as these show a good relationship to the individual speed of symptomatic decline in AD patients related to mitochondrial dysfunction.

Sleep, Cognitive impairment, and Alzheimer's disease: A Systematic Review and Meta-Analysis

Study Objectives

Mounting evidence implicates disturbed sleep or lack of sleep as one of the risk factors for Alzheimer's disease (AD), but the extent of the risk is uncertain. We conducted a broad systematic review and meta-analysis to quantify the effect of sleep problems/disorders on cognitive impairment and AD.

Methods

Original published literature assessing any association of sleep problems or disorders with cognitive impairment or AD was identified by searching PubMed, Embase, Web of Science, and the Cochrane library. Effect estimates of individual studies were pooled and relative risks (RR) and 95% confidence intervals (CI) were calculated using random effects models. We also estimated the population attributable risk.

Results

Twenty-seven observational studies (n = 69216 participants) that provided 52 RR estimates were included in the meta-analysis. Individuals with sleep problems had a 1.55 (95% CI: 1.25-1.93), 1.65 (95% CI: 1.45-1.86), and 3.78 (95% CI: 2.27-6.30) times higher risk of AD, cognitive impairment, and preclinical AD than individuals without sleep problems, respectively. The overall meta-analysis revealed that individuals with sleep problems had a 1.68 (95% CI: 1.51-1.87) times higher risk for the combined outcome of cognitive impairment and/or AD. Approximately 15% of AD in the population may be attributed to sleep problems.

Conclusion

This meta-analysis confirmed the association between sleep and cognitive impairment or AD and, for the first time, consolidated the evidence to provide an "average" magnitude of effect. As sleep problems are of a growing concern in the population, these findings are of interest for potential prevention of AD.

Pathophysiologic relationship between Alzheimer's disease, cerebrovascular disease, and cardiovascular risk: A review and synthesis

As the population ages due to demographic trends and gains in life expectancy, the incidence and prevalence of dementia increases, and the need to understand the etiology and pathogenesis of dementia becomes ever more urgent. Alzheimer's disease (AD), the most common form of dementia, is a complex disease, the mechanisms of which are poorly understood. The more we learn about AD, the more questions are raised about our current conceptual models of disease. In the absence of a cure or the means by which to slow disease progress, it may be prudent to apply our current knowledge of the intersection between AD, cardiovascular disease, and cerebrovascular disease to foster efforts to delay or slow the onset of AD. This review discusses our current understanding of the epidemiology, genetics, and pathophysiology of AD, the intersection between AD and vascular causes of dementia, and proposes future directions for research and prevention.

Prion Protein Modulates Monoaminergic Systems and Depressive-like Behavior in Mice

We sought to examine interactions of the prion protein (PrP(C)) with monoaminergic systems due to: the role of PrP(C) in both Prion and Alzheimer diseases, which include clinical depression among their symptoms, the implication of monoamines in depression, and the hypothesis that PrP(C) serves as a scaffold for signaling systems. To that effect we compared both behavior and monoaminergic markers in wild type (WT) and PrP(C)-null (PrP(-/-)) mice. PrP(-/-) mice performed poorly when compared with WT in forced swimming, tail suspension, and novelty suppressed feeding tests, typical of depressive-like behavior, but not in the control open field nor rotarod motor tests; cyclic AMP responses to stimulation of D1 receptors by dopamine was selectively impaired in PrP(-/-) mice, and responses to serotonin, but not to norepinephrine, also differed between genotypes. Contents of dopamine, tyrosine hydroxylase, and the 5-HT5A serotonin receptor were increased in the cerebral cortex of PrP(-/-), as compared with WT mice. Microscopic colocalization, as well as binding in overlay assays were found of PrP(C) with both the 5HT5A and D1, but not D4 receptors. The data are consistent with the scaffolding of monoaminergic signaling modules by PrP(C), and may help understand the pathogenesis of clinical depression and neurodegenerative disorders.

Analysis of hippocampal gene expression profile of Alzheimer's disease model rats using genome chip bioinformatics

In this study, an Alzheimer's disease model was established in rats through stereotactic injection of condensed amyloid beta 1–40 into the bilateral hippocampus, and the changes of gene expression profile in the hippocampus of rat models and sham-operated rats were compared by genome expression profiling analysis. Results showed that the expression of 50 genes was significantly up-regulated (fold change ≥ 2), while 21 genes were significantly down-regulated in the hippocampus of Alzheimer's disease model rats (fold change ≤ 0.5) compared with the sham-operation group. The differentially expressed genes are involved in many functions, such as brain nerve system development, neuronal differentiation and functional regulation, cellular growth, differentiation and apoptosis, synaptogenesis and plasticity, inflammatory and immune responses, ion channels/transporters, signal transduction, cell material/energy metabolism. Our findings indicate that several genes were abnormally expressed in the metabolic and signal transduction pathways in the hippocampus of amyloid beta 1–40-induced rat model of Alzheimer's disease, thereby affecting the hippocampal and brain functions.

Longitudinal relationships between Alzheimer disease progression and psychosis, depressed mood, and agitation/aggression

OBJECTIVES

Behavioral and psychological symptoms of dementia (BPSD) are prevalent in Alzheimer disease (AD) and are related to poor outcomes such as nursing home placement. No study has examined the impact of individual BPSD on dependence, a clinically important feature that reflects changing patient needs and their effect on caregivers. The current study characterized independent cross-sectional and longitudinal relationships between three BPSD (psychosis, depressed mood, and agitation/aggression), cognition, and dependence to better understand the interplay between these symptoms over time.

DESIGN

The Predictors Study measured changes in BPSD, cognition, and dependence every 6 months in patients with AD. Cross-sectional and longitudinal relationships between individual BPSD, cognition, and dependence over 6 years were characterized by using multivariate latent growth curve modeling. This approach characterizes independent changes in multiple outcome measures over time.

SETTING

Four memory clinics in the United States and Europe.

PARTICIPANTS

A total of 517 patients with probable AD.

MEASUREMENTS

Columbia University Scale for Psychopathology, modified Mini-Mental State Examination, and Dependence Scale.

RESULTS

Both psychosis and depressed mood at study entry were associated with worse subsequent cognitive decline. Independent of cognitive decline, initial psychosis was associated with worse subsequent increases in dependence. Rates of increase in agitation/aggression separately correlated with rates of declines in both cognition and independence.

CONCLUSIONS

Although purely observational, our findings support the poor prognosis associated with psychosis and depression in AD. Results also show that agitation/aggression tracks declines in cognition and independence independently over time. Targeted intervention for individual BPSD, particularly psychosis, could have broad effects not only on patient well-being but also on care costs and family burden.

Neuropsychiatric aspects of dementia

Dementia affects approximately 6.5% of people over the age of 65. Whilst cognitive impairment is central to the dementia concept, neuropsychiatric symptoms are invariably present at some stage of the illness. Neuropsychiatric symptoms result in a number of negative outcomes for the individual and their caregivers and are associated with higher rates of institutionalization and mortality. A number of factors have been associated with neuropsychiatric symptoms including neurobiological changes, dementia type, and illness severity and duration. Specific patient, caregiver and environmental factors are also important. Neuropsychiatric symptoms can be broadly divided into four clusters: psychotic symptoms, mood/affective symptoms, apathy, and agitation/aggression. Neuropsychiatric symptoms tend to persist over time although differing symptom profiles exist at various stages of the illness. Assessment should take into account the presenting symptoms together with an appreciation of the myriad of likely underlying causes for the symptoms. A structured assessment/rating tool can be helpful. Management should focus on non-pharmacological measures initially with pharmacological approaches reserved for more troubling symptoms. Pharmacological approaches should target specific symptoms although the evidence-base for pharmacological management is quite modest. Any medication trial should include an adequate appreciation of the risk-benefit profile in individual patients and discussion of these with both the individual and their caregiver.

Gene-behavior interaction of depressive symptoms and the apolipoprotein E {varepsilon}4 allele on cognitive decline

OBJECTIVE

Depressive symptoms and the apolipoprotein E (APOE) ε4 allele are independent risk factors for cognitive decline. However, it is not clear whether the presence of both depressive symptoms and the APOE ε4 allele increases cognitive decline.

METHODS

A prospective study of a population-based sample of 4150 (70% African American and 63% women) participants 65 years and older who were interviewed at 3-year intervals was conducted. Depressive symptoms were measured using the 10-item version of the Center for Epidemiologic Studies Depression scale, with each item coded as presence or absence of a symptom. The APOE genotype was ascertained by DNA samples collected during follow-up. Cognitive function was assessed at the initial and follow-up interviews (average follow-up of 9.2 years), using a standardized global cognitive score.

RESULTS

There were 1405 (34%) participants with one or more copies of the APOE ε4 allele. In participants with no depressive symptoms, cognitive function decreased by 0.0412 unit per year among those with no copies and 0.0704 unit per year among those with one or more copies of the APOE ε4 allele. For each additional symptom of depression, cognitive decline increased by 0.0021 unit per year among those with no copies and 0.0051 unit per year among those with one or more copies of the APOE ε4 allele. The three-way interaction of depressive symptoms, APOE ε4 allele, and time was significant (p = .021).

CONCLUSIONS

The association of depressive symptoms on cognitive decline was increased among participants with one or more copies of the APOE ε4 allele compared with those without the allele.

Depressive symptoms precede memory decline, but not vice versa, in non-demented older adults

OBJECTIVES

To determine whether depressive symptoms typically precede or follow memory declines.

DESIGN

An autoregressive latent trajectory model was used to examine the direction of the relationship between depressive symptoms and memory decline observed over 12 years.

SETTING

Washington/Hamilton Heights Inwood Columbia Aging Project, a community-based longitudinal study of aging and dementia in northern Manhattan.

PARTICIPANTS

Older adults initially without dementia(n = 2,425).

MEASUREMENTS

Memory composite scores were computed from three subscores of the Selective Reminding Test. Depressive symptoms were assessed using a 10-item version of the Center for Epidemiologic Studies Depression Scale. Analyses controlled for age, sex, recruitment wave,education, black race, and Hispanic ethnicity measured at baseline and chronic disease burden measured at each study visit.

RESULTS

Initial depressive symptoms predicted worse memory scores at the second study visit (B weight = − 0.03; P = .003) and accelerated memory decline over the entire study period (B weight = − 0.02; P = .03). Memory scores did not predict subsequent depressive symptoms.

CONCLUSION

These findings suggest that depressive symptoms precede memory decline, but not vice versa, in late life. This pattern of results is consistent with hypotheses that depression is a prodrome of dementia or a causal contributor to memory decline. Clinicians should be aware that depressive symptoms may represent an early indicator not only of dementia, as reported previously, but also of memory decline more generally.

Neuropsychiatric symptom clusters of Alzheimer's disease in Hong Kong Chinese: prevalence and confirmatory factor analysis of the Neuropsychiatric Inventory

BACKGROUND

The aim of this study was to investigate the clustering of symptoms on the Neuropsychiatric Inventory (NPI) and the relative prevalence of symptom clusters in mild and moderate Alzheimer's disease (AD).

METHODS

Confirmatory factor analysis (CFA) was performed on the polychoric correlation matrix of 12 NPI items (scored yes or no) using the weighted least squares with mean and variance adjustment (WLSMV) estimator in Mplus (N = 224 community-dwelling Chinese persons with mild/moderate AD). Severity of AD was determined by Clinical Dementia Rating scores. The relative model fit of three competing measurement models (also known as factor structures) was tested using a modified χ2 difference test. Prevalence rates across mild and moderate stages were compared using χ2 tests. Furthermore, the measurement model of choice was cross-validated in an independent sample of 181 community-dwelling persons with dementia.

RESULTS

CFA supported a four-factor model, namely behavioral problems (agitation/aggressiveness, disinhibition, irritability, and aberrant motor behavior), psychosis (delusions and hallucinations), mood disturbance (depression, anxiety, sleep, appetite, and apathy), and euphoria (a stand-alone item that is equivalent to the factor). The most prevalent symptom clusters were behavioral (72%) and mood (69%) disturbances, followed by psychosis (45%). Euphoria was rare (6%). All syndromes were more prevalent in moderate than in mild stage, except for euphoria. In addition, the four-factor model was replicated in the cross-validation sample.

CONCLUSIONS

The four syndromes provide a parsimonious conceptualization of neuropsychiatric symptoms corresponding to clinical observations and neurochemical changes of the disease. The independent replication in the second sample supports generalization of the four-factor model in Chinese persons with AD.

Cerebral correlates of psychotic syndromes in neurodegenerative diseases

Psychosis has been recognized as a common feature in neurodegenerative diseases and a core feature of dementia that worsens most clinical courses. It includes hallucinations, delusions including paranoia, aggressive behaviour, apathy and other psychotic phenomena that occur in a wide range of degenerative disorders including Alzheimer's disease, synucleinopathies (Parkinson's disease, dementia with Lewy bodies), Huntington's disease, frontotemporal degenerations, motoneuron and prion diseases. Many of these psychiatric manifestations may be early expressions of cognitive impairment, but often there is a dissociation between psychotic/behavioural symptoms and the rather linear decline in cognitive function, suggesting independent pathophysiological mechanisms. Strictly neuropathological explanations are likely to be insufficient to explain them, and a large group of heterogeneous factors (environmental, neurochemical changes, genetic factors, etc.) may influence their pathogenesis. Clinico-pathological evaluation of behavioural and psychotic symptoms (PS) in the setting of neurodegenerative and dementing disorders presents a significant challenge for modern neurosciences. Recognition and understanding of these manifestations may lead to the development of more effective preventive and therapeutic options that can serve to delay long-term progression of these devastating disorders and improve the patients' quality of life. A better understanding of the pathophysiology and distinctive pathological features underlying the development of PS in neurodegenerative diseases may provide important insights into psychotic processes in general.

Sleep quality and 1-year incident cognitive impairment in community-dwelling older adults

STUDY OBJECTIVES

To examine in cognitively intact older men and women the associations between subjective sleep quality and 1-yr incident cognitive impairment.

DESIGN

Prospective cohort study.

SETTING

General community.

PARTICIPANTS

1,664 cognitively intact individuals age 65 to 96 years.

MEASUREMENTS AND RESULTS

Sleep quality at baseline was measured using the Pittsburgh Sleep Quality Index (PSQI). Cognitive functioning was assessed at baseline and 12 months later using the Mini-Mental State Examination (MMSE). Incident general cognitive impairment was defined according to a follow-up MMSE score below the 15(th) percentile according to normative data and of at least 2 points below baseline. General cognitive impairments were also separated into amnestic and nonamnestic subtypes according to MMSE delayed recall performance. Associations between sleep quality indicators at baseline and incident cognitive impairment were assessed by odds ratio (OR) adjusted for age, education, baseline MMSE score, psychotropic drug use, anxiety, depressive episodes, cardiovascular conditions, and chronic diseases. Results revealed that global PSQI score was significantly linked with incident cognitive impairment (OR 1.17, 95% confidence interval (CI) 1.05-1.30) in men, but not in women. In women, sleep disturbance score (OR 2.62, 95% CI 1.41-4.86) and long sleep duration (≥ 9 hr; OR 3.70, 95% CI 1.49-9.17) were associated with nonamnestic and amnestic incident cognitive impairment, respectively. In men, short sleep duration (≤ 5 hr; OR 4.95, 95% CI 1.72-14.27) and habitual sleep efficiency score (OR 1.94, 95% CI 1.42-2.66) were associated with amnestic and general incident cognitive impairment, respectively.

CONCLUSIONS

Sleep quality in older adults should receive particular attention by clinicians because poor sleep quality can be an early sign of cognitive decline.

Missense substitutions associated with behavioural disturbances in Alzheimer's disease (AD)

Behavioural and psychological symptoms in dementia, or BPSD, occur in the majority of Alzheimer's disease (AD) patients. They are associated with considerable patient morbidity and greater care-giver stress. There is some evidence suggesting that BPSD have a genetic component and a large number of studies have examined the association of candidate genes with these symptoms. This review provides a comprehensive summary of all the published studies investigating the association of candidate gene missense substitutions with BPSD. Missense substitutions could potentially alter protein function or render the protein non-functional, resulting in phenotypic consequences. More than 80 studies investigating the association of 8 missense substitutions in 7 genes with BPSD were identified. However, results of these studies are contradictory and do not provide firm support for these associations. Larger studies and more systematic approaches will delineate the association of missense substitutions with behavioural symptoms in AD.

Comparison of polysomnographic variables and their relationship to cognitive impairment in patients with Alzheimer's disease and frontotemporal dementia

Polysomnograhic (PSG) studies in Alzheimer's disease (AD) show REM sleep abnormalities, which may be indicative for the deterioration of cholinergic pathways and probably closely linked to declarative memory impairment. To clarify the specificity of the association between sleep and cognitive impairment in dementia, we compared AD patients with patients suffering from frontotemporal dementia (FTD) with regard to PSG and neuropsychological variables. 15 AD and 6 FTD patients underwent polysomonography and a neuropsychological battery (CERAD-NB). Group differences (age: AD > FTD; education level: AD < FTD) were considered as covariates. Polysomnography revealed a trend towards increased REM latency and reduced REM sleep in AD, as well as a decrease of stage 2 sleep, however, at least partly due to effects of age. Declarative memory was more impaired in AD than in FTD, but this difference disappeared when adjusted for covariates. While no relationship was found between REM sleep and CERAD-NB parameters, strong positive correlations between stage 2 sleep and declarative memory measures were observed, which were also detectable when analyzing both groups separately. Based on these results we conclude that REM sleep alterations may be specific for AD, distinguishable from other dementia diagnoses, whereas NonREM stage 2 sleep may be related to declarative memory formation in dementia independent of subtype.

Clinicopathological correlates of behavioral and psychological symptoms of dementia

Behavioral and psychological symptoms are commonly observed in a majority of demented patients at some time during the course of their illness. Many of these psychiatric manifestations, especially those related to mood, may be early expressions of dementia and/or mild cognitive impairment. The literature suggests that behavioral and psychological symptoms of dementia (BPSD) are an integral part of the disease process. The dissociation, in many cases, between BPSD and the rather linear decline in cognitive functions suggests that independent pathophysiological mechanisms give rise to these symptoms. A review of the neuroimaging and neuropathology literature indicates that BPSD are the expression of regional rather than diffuse brain pathology. Psychotic symptoms in demented patients usually demonstrate preferential involvement of the frontal lobe and/or limbic regions. Visual hallucinations differentiate themselves from other psychotic symptoms by their tendency to involve the occipital lobes. There is a significant association between apathy and structural changes of the anterior cingulate gyrus. White matter hyperintensities occur in a significant number of depressed patients; otherwise, there is lack of association between depression and either specific brain changes or affected regions. Strictly neuropathological explanations are likely to be insufficient to explain BPSD. Environmental changes, neurochemical abnormalities, past psychiatric history (including premorbid personality), social history (e.g., intellectual achievement and life-long learning), family history, and genetic susceptibility are factors, among others, that influence BPSD.

A tune in "a minor" can "b major": a review of epidemiology, illness course, and public health implications of subthreshold depression in older adults

BACKGROUND

With emphasis on dimensional aspects of psychopathology in development of the upcoming DSM-V, we systematically review data on epidemiology, illness course, risk factors for, and consequences of late-life depressive syndromes not meeting DSM-IV-TR criteria for major depression or dysthymia. We termed these syndromes subthreshold depression, including minor depression and subsyndromal depression.

METHODS

We searched PubMed (1980-Jan 2010) using the terms: subsyndromal depression, subthreshold depression, and minor depression in combination with elderly, geriatric, older adult, and late-life. Data were extracted from 181 studies of late-life subthreshold depression.

RESULTS

In older adults subthreshold depression was generally at least 2-3 times more prevalent (median community point prevalence 9.8%) than major depression. Prevalence of subthreshold depression was lower in community settings versus primary care and highest in long-term care settings. Approximately 8-10% of older persons with subthreshold depression developed major depression per year. The course of late-life subthreshold depression was more favorable than that of late-life major depression, but far from benign, with a median remission rate to non-depressed status of only 27% after ≥1 year. Prominent risk factors included female gender, medical burden, disability, and low social support; consequences included increased disability, greater healthcare utilization, and increased suicidal ideation.

LIMITATIONS

Heterogeneity of the data, especially related to definitions of subthreshold depression limit our ability to conduct meta-analysis.

CONCLUSIONS

The high prevalence and associated adverse health outcomes of late-life subthreshold depression indicate the major public health significance of this condition and suggest a need for further research on its neurobiology and treatment. Such efforts could potentially lead to prevention of considerable morbidity for the growing number of older adults.

Diagnostic correlates of Alzheimer dementia in a U.S. Nationwide inpatient sample

INTRODUCTION

Alzheimer dementia (ALZ-D) is among the most frequent diseases in the elderly. Several somatic and psychiatric disorders have been suggested to be related to this diagnosis. The aim of this analysis of a large and representative U.S. nationwide inpatient sample (NIS) was to identify diagnostic correlates of ALZ-D in subjects aged 60 years and older.

METHODS

Of the total sample of 800,457 inpatient subjects ( approximately 2% of all inpatients in 2004), 315,244 individuals were 60 years or older. Of these, 9,572 (3.03%) received a diagnosis of ALZ-D, whereas 33,367 (10.59%) were diagnosed with osteoarthritis (OA) and served as a comparison group. Comparisons of potential somatic and psychiatric diagnostic correlates were conducted.

RESULTS

As determined by both univariate comparison and multivariate logistic regression analysis, after controlling for age and gender, subjects with ALZ-D (versus OA) had an overall higher rate of diagnoses of diseases of the vascular system (stroke: odds ratio 1.69; 95% confidence interval: 1.25-2.30) and psychotic and affective disorders (bipolar: 2.78 [1.26-6.12]; schizoaffective: 3.06 [2.10-4.47]). Increasing age and male gender were positively associated with the diagnosis of ALZ-D.

DISCUSSION

Many somatic diagnoses related to ALZ-D were confirmed by these analyses of the NIS. However, psychotic and affective disorders were identified to be equally significant correlates of ALZ-D, even in the presence of all other disorders. Prospective and longitudinal data are needed to investigate potential causal and temporal relationships between ALZ-D with somatic and psychiatric disorders.

Historical note on Darwin's consideration of early-onset dementia in older persons, thirty-six years before Alzheimer's initial case report

In February 1871, the great naturalist Charles Darwin received a letter from Dr. James-Crichton Browne, who was serving as Director of the largest lunatic asylum in England. Darwin had been introduced to Crichton-Browne 2 years earlier by Henry Maudsley, who believed that the young psychiatrist could provide Darwin with clinical examples of extreme emotional expression, to aid him in preparing to write Expression of the Emotions in Man and Animals (1872). This particular letter from Crichton-Browne contained the first and only reference to "premature dotage" or "senile decay" found anywhere in Darwin's entire corpus of correspondence, which amounted to more than 80,000 pages of handwritten letters to nearly 2,000 individuals throughout his lifetime. Moreover, this letter from Crichton-Browne, received by Darwin 36 years before the first case report of senile dementia by Professor Alois Alzheimer, explicitly noted that such premature dotage is the result of "brain wasting." Crichton-Browne believed that senile dementia was the result of a central nervous system disease, with the emotional lability observed in his patients linked inextricably to the disease process. This early hypothesis, of interest to Darwin in 1871, anticipated the groundbreaking neurohistopathologic research and case description by Alzheimer 36 years later, and has been confirmed by all clinical research in this field since 1907. This concordance between psychological symptoms and Alzheimer's disease continues to be an important area of study, leading to recent advances in our understanding of the genetics, neurobiology, and neurochemistry of psychiatric illness in older adults.

Pharmacological management of psychosis in elderly patients with parkinsonism

Parkinsonism is a characteristic feature of Parkinson's disease and dementia with Lewy bodies and is commonly seen in Alzheimer's disease. Psychosis commonly appears during the course of these illnesses. Treatment of parkinsonism with antiparkinsonian medications constitutes an additional risk factor for the appearance or worsening of psychosis. Conversely, treatment of psychosis with antipsychotic drugs in patients with parkinsonism might worsen the underlying movement disorder, especially in the elderly. In this article, we review parkinsonian conditions in the elderly and offer guidelines to assess and manage comorbid psychosis. We focus on the pharmacologic management of psychosis with atypical antipsychotic medications and briefly review the role of acetylcholinesterase inhibitors.

Pattern of brain atrophy in elderly patients with depression revealed by voxel-based morphometry

In this study, we explored to what extent brain abnormalities can be identified in specific brain structures of patients suffering from late onset depression. We examined the structural difference in regional gray and white matter volume between 14 community-dwelling patients suffering from geriatric depression and 20 age-matched non-depressed normal subjects by voxel-based morphometry (VBM) based on magnetic resonance imaging. All subjects also underwent an extensive neuropsychological assessment. Compared with control subjects, patients with depression were impaired in measures of verbal and visual memory, construction, executive ability, and information-processing speed. VBM of gray matter revealed a significant decrease of volume in the right rostral hippocampus, in the right amygdala and in the medial orbito-frontal cortex (gyrus rectus) bilaterally. In the correlation analysis of gray matter volume with the score of the geriatric depression scale, we observed a negative correlation with the medial orbito-frontal cortex (gyrus rectus) bilaterally. There were no differences in white matter volumes between patients with depression and healthy control subjects. The most important limitation of this study was sample size. A larger sample size may have improved detection of changes not reaching significance. Furthermore, our results may not be generalizable across depression severity or to hospitalized patients. The findings are consistent with our hypothesis that depression in the elderly is associated with local gray matter dysfunction.

Apolipoprotein E epsilon4 allele genotype and the effect of depressive symptoms on the risk of dementia in men: the Honolulu-Asia Aging Study

CONTEXT

The apolipoprotein E epsilon4 (APOE epsilon4) allele is a genetic risk factor for Alzheimer disease. Recently, depression has also become recognized as a risk factor for dementia. However, the possible effect of the APOE genotype on the association between depression and dementia is unexamined.

OBJECTIVE

To examine the independent and combined effects of depression and APOE epsilon4 on the risk of dementia and its subtypes.

DESIGN

The Honolulu-Asia Aging Study, a population-based prospective cohort study of Japanese American men.

SETTINGS AND PARTICIPANTS

Depressive symptoms and presence of the APOE epsilon4 allele were assessed between March 1991 and October 1993 in 1932 cognitively healthy men aged 71 to 90 years. Incident cases of dementia were diagnosed during approximately 6 years of follow-up based on neurologic assessment at 2 repeated examinations (April 1994-April 1996 and October 1997-February 1999).

MAIN OUTCOME MEASURES

Overall dementia, Alzheimer disease, and vascular dementia.

RESULTS

The interaction of depression and APOE epsilon4 was statistically significant in the analytical models. Compared with men with neither APOE epsilon4 nor depression, the risk of dementia in nondepressed men with APOE epsilon4 was not significant (hazard ratio, 1.1; 95% confidence interval [CI], 0.6-1.8); however, depressed men without APOE epsilon4 had a 1.6-fold greater risk (95% CI, 0.8-3.0), whereas depressed men with APOE epsilon4 had a 7.1-fold greater risk (95% CI, 3.0-16.7) of dementia. For subtypes, we found similar increased risks of Alzheimer disease.

CONCLUSIONS

The APOE epsilon4 status modifies the association between depressive symptoms and dementia in elderly men. Because individuals with depressive symptoms and the APOE epsilon4 allele had a markedly increased risk of dementia, one might be especially watchful for early signs of dementia in the older person with depression who is also positive for the APOE epsilon4 allele. Because this cohort includes only men, further investigation in women is required.

Herceptin

The biology of the human epidermal growth factor (EGF) receptor-2 (HER2) has been reviewed numerous times and provides an excellent example for developing a targeted cancer therapeutic. Herceptin, the FDA-approved therapeutic monoclonal antibody against HER2, has been used to treat over 150,000 women with breast cancer. However, the developmental history of Herceptin, the key events within the program that created pivotal decision points, and the reasons why decisions were made to pursue the monoclonal antibody approach have never been adequately described. The history of Herceptin is reviewed in a way which allows the experience to be shared for the purposes of understanding the drug discovery and development process. It is the objective of this review to describe the pivotal events and explain why critical decisions were made that resulted in the first therapeutic to successfully target tyrosine kinases in cancer. New approaches and future prospects for therapeutics targeting the HER family are also discussed.

Effective electroconvulsive therapy in a 92-year-old dementia patient with psychotic feature

A 92-year-old woman who suffered from dementia with psychotic feature was admitted to a psychiatric ward. She refused to eat or take any medications. After 0.5 mg i.v. injection haloperidol, prolongation of QTc interval occurred in the electrocardiogram. Therefore two sessions of electroconvulsive therapy (ECT) were performed carefully after informed consent was obtained by her family. Almost no psychotic symptoms were observed after the first ECT. No cognitive side-effects were observed during and after the two ECT sessions. This demonstrates that ECT can be used as an alternative treatment when elderly dementia patients with psychotic feature cannot tolerate medication.