Long-term outcome of depressive pseudodementia in the elderly

Association of cognitive impairment with the interaction between chronic kidney disease and depression: findings from NHANES 2011-2014

BACKGROUND

Cognitive impairment (CoI), chronic kidney disease (CKD), and depression are prevalent among older adults and are interrelated, imposing a significant disease burden. This study evaluates the association of CKD and depression with CoI and explores their potential interactions.

METHOD

Data for this study were sourced from the 2011-2014 National Health and Nutritional Examination Survey (NHANES). Multiple binary logistic regression models assessed the relationship between CKD, depression, and CoI while controlling for confounders. The interactions were measured using the relative excess risk of interaction (RERI), the attributable proportion of interaction (AP), and the synergy index (S).

RESULTS

A total of 2,666 participants (weighted n = 49,251,515) were included in the study, of which 700 (16.00%) had CoI. After adjusting for confounding factors, the risk of CoI was higher in patients with CKD compared to non-CKD participants (odds ratio [OR] = 1.49, 95% confidence interval [CI]:1.12-1.99). The risk of CoI was significantly increased in patients with depression compared to those without (OR = 2.29, 95% CI: 1.73-3.03). Furthermore, there was a significant additive interaction between CKD and depression in terms of the increased risk of CoI (adjusted RERI = 2.01, [95% CI: 0.31-3.71], adjusted AP = 0.50 [95% CI: 0.25-0.75], adjusted S = 2.97 [95% CI: 1.27-6.92]).

CONCLUSION

CKD and depression synergistically affect CoI, particularly when moderate-to-severe depression co-occurs with CKD. Clinicians should be mindful of the combined impact on patients with CoI. Further research is needed to elucidate the underlying mechanisms and assess the effects specific to different CKD stages.

Common mental health disorders and cognitive decline in a longitudinal Down syndrome cohort

BACKGROUND

Down syndrome is the most common genetic cause of intellectual disability and Alzheimer's disease. In the general population, common mental disorders (CMDs), including anxiety, depression and obsessive-compulsive disorder, are linked to cognitive decline and higher risk for dementia. It is not known how CMDs affect longer-term cognitive outcomes in Down syndrome, and there is often diagnostic uncertainty in older people with Down syndrome and psychiatric comorbidity.

AIMS

To study the influence of CMDs on cognitive ability and whether they are related longitudinally to development of clinical signs of Alzheimer's disease in Down syndrome.

METHOD

We followed 115 individuals with Down syndrome, 27 of whom were diagnosed with a CMD, over approximately 3 years. Changes in cognitive and behavioural outcomes between baseline and follow-up assessment were analysed, with comparisons made between those with and without a comorbid CMD. Age, gender, apolipoprotein E status and level of intellectual disability were included as covariates.

RESULTS

No significant association between presence of a CMD and poorer performance on cognitive tasks or informant-rated decline over time was observed (P > 0.05).

CONCLUSIONS

Our results suggest that a diagnosis of a CMD does not have a significant negative effect on long-term cognitive or behavioural outcomes in individuals with Down syndrome. In individuals with stable or treated CMD, subsequent cognitive decline is likely indicative of Alzheimer's disease rather than a consequence of mental disorder.

Is later-life depression a risk factor for Alzheimer's disease or a prodromal symptom: a study using post-mortem human brain tissue?

BACKGROUND

Depression and dementia are both common diseases. Although new cases of depression are more common in younger adults, there is a second peak at the age of 50 years suggesting a different pathological process. Late-life depression (LLD) is associated with dementia. However, it remains unclear whether depression represents a dementia prodrome or is a true risk factor for its development. LLD is thought to have a vascular component and this may be a possible link between depression and dementia. We hypothesised that later-life depression is a prodromal manifestation of dementia and would therefore be associated with more AD, and/or ischaemic brain abnormalities that are present in earlier-life depression or in age- and sex-matched controls.

METHODS

We assessed post-mortem orbitofrontal cortex and dorsolateral pre-frontal cortex from 145 individuals in 4 groups: 28 18-50-year-olds with depression, 30 older individuals (ages 51-90) with depression, 28 with early AD (Braak tangle stages III-IV) and 57 matched controls (17 early-life, 42 later-life). Levels of Aβ, phospho-tau and α-synuclein were assessed by immunohistochemistry and ELISA. To quantify chronic ischaemia, VEGF, MAG and PLP1 were measured by ELISA. To assess pericyte damage, PDGFRB was measured by ELISA. For blood-brain barrier leakiness, JAM-A, claudin 5 and fibrinogen were measured by ELISA. To quantity endothelial activation, the ratio of ICAM1:collagen IV was assessed by immunohistochemistry.

RESULTS

There was no evidence of chronic cerebral hypoperfusion or increased Aβ/tau in either depression group. There was also no indication of pericyte damage, increased blood-brain barrier leakiness or endothelial activation in the OFC or DLPFC in the depression groups.

CONCLUSIONS

Contrary to some previous findings, we have not found evidence of impaired vascular function or increased Aβ in LLD. Our study had a relatively small sample size and limitations in the availability of clinical data. These results suggest that depression is a risk factor for dementia rather than an early manifestation of AD or a consequence of cerebral vascular insufficiency.

Does depression in mid-life predispose to greater cognitive decline in later life in the Whitehall II cohort?

BACKGROUND

Later-life depression appears to have different symptomatology and possibly underlying pathology to younger adults. Depression is linked to dementia but whether it is a risk factor or an early sign of dementia remains unclear. Neuroinflammation is increasingly recognised in both conditions.

AIMS

To investigate the link between depression, inflammation and dementia. We hypothesised that recurrent depression increases the rate of cognitive decline in older adults and that this effect is modified by anti-inflammatory medication.

METHODS

We used data from Whitehall II including cognitive test results and reliable measures to assess depression. Depression was defined as a self-reported diagnosis or a score of ≥20 on the CESD. The presence/absence of inflammatory illness was assessed using a standardised list of inflammatory conditions. Individuals with dementia, chronic neurological and psychotic conditions were excluded. Logistic and linear regression was used to examine the effect of depression on cognitive test performance and the effect of chronic inflammation.

LIMITATIONS

Lack of clinical diagnoses of depression.

RESULTS

There were 1063 individuals with and 2572 without depression. Depression did not affect deterioration in episodic memory, verbal fluency or the AH4 test at 15-year follow up. We found no evidence of an effect of anti-inflammatory medication. Depressed individuals had worse cross-sectional performance on the Mill Hill test and tests of abstract reasoning and verbal fluency at both baseline and 15-year follow-up.

CONCLUSIONS

Using a UK based study with a long follow-up interval we have shown that depression in individuals aged >50 is not associated with increased cognitive decline.

fNIRS Assessment during Cognitive Tasks in Elderly Patients with Depressive Symptoms

This study aimed to investigate differences in prefrontal cortex activation between older adults with and without depressive symptoms during cognitive tasks using functional near-infrared spectroscopy (fNIRS). We examined 204 older participants without psychiatric or neurological disorders who completed the Geriatric Depression Scale, digit span, Verbal Fluency Test, and Stroop test. At the same time, prefrontal cortex activation was recorded using fNIRS. During the Stroop test, significantly reduced hemodynamics were observed in the depressive-symptom group. The mean accΔHbO₂ of all channel averages was 0.14 μM in the control group and -0.75 μM in the depressive-symptom group (p = 0.03). The right hemisphere average was 0.13 μM and -0.96 μM, respectively (p = 0.02), and the left hemisphere average was 0.14 μM and -0.54 μM, respectively (p = 0.12). There was no significant difference in hemodynamic response (mean accΔHbO₂) between the two groups during the digit span backward and VFT. In conclusion, reduced hemodynamics in the frontal cortex of the depressive-symptom group has been observed. The frontal fNIRS signal and the Stroop task may be used to measure depressive symptoms sensitively in the elderly.

Association of subclinical depressive symptoms and sleep with cognition in the community-dwelling older adults

BACKGROUND

/Purpose: This study aimed to explore the association of subclinical depressive symptoms and sleep with cognition in community-dwelling Taiwanese older adults.

METHODS

This four-year prospective cohort study (2015-2019) included 379 participants aged 65 years or older from the annual senior health checkup program at National Taiwan University Hospital who were followed up two years later. Global and domain cognitive functions were assessed using validated neuropsychological tests. Depressive symptoms were evaluated using the Center for Epidemiologic Studies Depression (CES-D) Scale. Sleep quality was evaluated using the Pittsburg Sleep Quality Index (PSQI). Excessive daytime sleepiness was assessed using the Epworth Sleepiness Scale (ESS). Generalized linear mixed models were used to explore the associations of subclinical depressive symptoms and sleep variables with cognition, adjusting for important covariates. Stratification analyses were performed using the sleep variables.

RESULTS

Over time, depressive symptoms were associated with poor performance of memory (βˆ = 0.24, P = 0.04) and executive function (βˆ = -0.24, P = 0.03). Poor sleep quality (elevated PSQI score) was associated with poor memory performance (βˆ = -0.04 to -0.03, P < 0.05). Excessive daytime sleepiness (elevated ESS score) was associated with poor performance of memory (βˆ = -0.02, P < 0.05) and executive function (βˆ = -0.02, P = 0.001). At baseline, better sleep quality and no excessive daytime sleepiness were associated with better memory performance over time.

CONCLUSION

Subclinical depressive symptoms, worse sleep quality, and excessive daytime sleepiness were differentially associated with impairment of cognitive domains (mainly memory and executive function).

Towards an understanding of the pathological basis of senile depression and incident dementia: Implications for treatment

Senile depression (SD) is a heterogeneous syndrome. Several clinical profiles are more likely to appear in SD than in early-life depression, but it remains unclear whether the pathophysiology is different. The prevalence of dementia increases with aging, and the underlying pathophysiological processes in the preclinical phase begin even before cognitive deficits or neurological signs appear. SD may be either a risk factor for developing dementia or a prodromal stage of dementia. The inconsistent findings regarding the association between SD and incident dementia may be attributable to the neuropathological heterogeneity underlying SD. Most studies have focused on patients with the clinical diagnosis of Alzheimer disease (AD) as an outcome, but several clinicopathological studies suggest that primary age-related tauopathy and argyrophilic grain disease may account for a proportion of cases clinically misdiagnosed as AD in the elderly population. Furthermore, most AD cases have additional neuropathologic changes such as cerebrovascular disease and Lewy body disease. Here, we review the neuropathological findings linking SD to incident dementia, focusing on common age-related neuropathologies. In particular, the roles of disturbance of neural circuity, imbalance of monoaminergic systems, dysregulation of the hypothalamic-pituitary-adrenal axis, and elevated neuroinflammatory status are discussed. Finally, we review the current treatment of SD in the context of age-related neuropathological changes.

Apathy, anhedonia and cognitive dysfunction: common symptoms of depression and neurological disorders

Depression is one of the most common mental disorders in neurological practice. Among other symptoms of depression, a symptom complex represented by apathy, anhedonia, and cognitive impairment plays an important role. This review presents the clinical characteristics of the symptoms described above and discusses modern neurochemical and neuroimaging concepts of their pathogenesis. The problem of pathogenetically substantiated therapy of depression with a predominance of apathy, anhedonia and cognitive impairment is discussed. Fundamental and clinical arguments are presented in favor of the high efficacy of vortioxetine in depression with a predominance of apathy, anhedonia, and cognitive impairment. 

Guidelines for diagnosis and treatment of depression in older adults: A report from the Japanese Society of mood disorders

The Committee for Treatment Guidelines of Mood Disorders, Japanese Society of Mood Disorders, published a Japanese guideline for the treatment of late-life depression in 2020. Based on that guideline, the present guideline was developed and revised to incorporate the suggestions of global experts and the latest published evidence. In the diagnosis of late-life depression, it is important to carefully differentiate it from bipolar disorders, depressive states caused by physical and organic brain disease, drug effects, and dementia, and to determine the comorbidity between late-life depression and dementia. It is necessary to fully understand the clinical characteristics and psychosocial background of late-life depression, evaluate the patient's condition, and provide basic interventions based on these factors. Problem-solving therapy, reminiscence therapy/life review therapy, and behavioral activation therapy, and other forms of psychotherapy can reduce depressive symptoms. In terms of pharmacotherapy, newer antidepressants or non-tricyclic antidepressants are recommended for late-life depression, and it is recommended that the efficacy of least the minimal effective dosage should first be determined. Switching antidepressants and aripiprazole augmentation can be used to treatment-resistant therapy. Electroconvulsive therapy and repetitive transcranial magnetic stimulation have demonstrated usefulness for late-life depression. Exercise therapy, high-intensity light therapy, and diet therapy also show some effectiveness and are useful for late-life depression. Continuation therapy should be maintained for at least 1 year after remission.

Recurrent depression has persistent effects on cognition but this does not appear to be mediated by neuroinflammation

BACKGROUND

Later-life depression appears to be different to depression in younger adults. The underlying pathology may also differ. Depression is linked to dementia but whether it is a risk factor or an early sign of a developing dementia remains unclear. Neuroinflammation is increasingly recognised in both depression and Alzheimer's Disease.

AIMS

To investigate the link between depression, inflammation and dementia. We hypothesised that recurrent depression has adverse effects on performance in cognitive tests in middle to older age and that this effect is modified by anti-inflammatory medication.

METHODS

We identified UK based cohort studies which included individuals aged >50, had medical information, results from detailed cognitive testing and had used reliable measures to assess depression. Individuals with recurrent depression had ≥ 2 episodes of depression. Controls had no history of depression. The presence/absence of inflammatory illness was assessed using a standardised list of inflammatory conditions. Individuals with dementia, chronic neurological and psychotic conditions were excluded. Logistic and linear regression were used to examine the effect of depression on cognitive test performance and the mediating effect of chronic inflammation.

RESULTS

Unexpectedly in both studies there was evidence that those with recurrent depression performed better in some cognitive tasks (e.g Mill Hill vocabulary) but worse in others (e.g. reaction time). In UK Biobank there was no evidence that anti-inflammatories moderated this effect.

LIMITATIONS

Cross-sectional assessment of cognition.

CONCLUSIONS

Although previous recurrent depression has small effects on cognitive test performance this does not appear to be mediated by chronic inflammatory disease.

Depressive symptoms with cognitive dysfunction increase the risk of cognitive impairment: analysis of the Korean Longitudinal Study of Aging (KLoSA), 2006-2018

OBJECTIVES

Geriatric depression complicates cognitive health in older adults. This study aims to investigate the impact of depressive symptoms on cognitive impairment in community-dwelling older adults, depending on whether cognitive dysfunction accompanied.

DESIGN

A community-based longitudinal cohort study.

SETTING

This study analyzed data from the Korean Longitudinal Study of Aging (KLoSA) from 2006 to 2018.

PARTICIPANTS

Among 10,254 individuals who were registered in the KLoSA study, a total of 9119 subjects met the criteria, and 4547 subjects were included in the final analysis. The subjects were grouped into 4 categories based on depressive symptoms and cognitive dysfunction at baseline assessment: "normal control" (NC, n = 3341), "depression only" (Dep-only, n = 652), "cognitive dysfunction only" (CD-only, n = 393), and "depression with cognitive dysfunction" (Dep-CD, n = 161).

MEASUREMENTS

Cognitive impairment 10 years later was defined as K-MMSE scores below two percentile on demographically adjusted norms.

RESULTS

Ten-year survival, that is, not experiencing cognitive impairment, was 80 $$ \pm \,$$1% in NC group, 72 $$ \pm $$ 2% in Dep-only group, 52 $$ \pm $$ 3% in CD-only group, and 44 $$ \pm $$ 5% in Dep-CD group. The hazard ratio (HR) of the Dep-only group (HR = 1.18, 95% CI, 0.97-1.43, n.s.) did not differ from that of the NC group, but the HR of the Dep-CD group was significantly higher (HR = 2.85, 95% CI, 2.23-3.66, p < 0.001) than the NC group. When the Dep-CD group was compared to the CD-only group, the HR was 1.13 (95% CI, 0.85-1.49, n.s.), which indicates that it did not significantly differ from the CD-only group.

CONCLUSIONS

Our findings suggest that depressive symptoms with cognitive dysfunction are associated with a higher risk of cognitive impairment. Furthermore, cognitive dysfunction occurring with depressive symptoms is as much a risk for cognitive impairment as is pure cognitive dysfunction. Thus, healthcare providers should pay close attention to the community-dwelling elderly when depressive symptoms occur with cognitive dysfunction.

Untreated depressive symptoms significantly worsen quality of life in old age and may lead to the misdiagnosis of dementia: a cross-sectional study

BACKGROUND

Several studies demonstrated the role of depressive mood and cognitive impairment in the background of elevated mortality and decreased Quality of Life (QoL) in old age. Our aim was to assess depressive and cognitive symptoms among older people in order to determine if those are recognized and treated or not, to elucidate the association between them and to investigate their impact on QoL.

METHODS

In the framework of the ICT4Life project self-administered questionnaires and clinical screening tools were used to assess QoL, depressive symptoms and cognitive functions of 60 older persons over the age of 65.

RESULTS

Males found to be depressed (53.8 vs. 40.4%) and cognitively declined (53.8 vs. 48.9%) more frequently; and had higher scores on the depression (6.85 vs. 5.32) and lower on the QoL (47.38 vs. 50.19) scales. Depressed older persons had lower cognitive levels (24.39 vs. 21.52) and their QoL was significantly poorer (53.97 vs. 43.85) than that of the non-depressed subjects. Depressive symptoms were detected in almost half of the older adults (43.9%), and the majority (80.77%) did not receive antidepressant medication.

CONCLUSIONS

Depressive and cognitive symptoms found to be common among older people, but were not recognized and treated in most cases. Close correlation between depression and cognitive impairment was also confirmed, as well as the key role of depression in the background of pseudo-dementia and QoL decline. Early recognition of depressive symptoms is important not only to treat the underlying mood disorder, but also to improve QoL of older persons.

Functional cognitive disorders: a systematic review

Cognitive symptoms are common, and yet many who seek help for cognitive symptoms neither have, nor go on to develop, dementia. A proportion of these people are likely to have functional cognitive disorders, a subtype of functional neurological disorders, in which cognitive symptoms are present, associated with distress or disability, but caused by functional alterations rather than degenerative brain disease or another structural lesion. In this Review, we have systematically examined the prevalence and clinical associations of functional cognitive disorders, and related phenotypes, within the wider cognitive disorder literature. Around a quarter of patients presenting to memory clinics received diagnoses that might indicate the presence of functional cognitive disorders, which were associated with affective symptoms, negative self-evaluation, negative illness perceptions, non-progressive symptom trajectories, and linguistic and behavioural differences during clinical interactions. Those with functional cognitive disorder phenotypes are at risk of iatrogenic harm because of misdiagnosis or inaccurate prediction of future decline. Further research is imperative to improve diagnosis and identify effective treatments for functional cognitive disorders, and better understanding these phenotypes will also improve the specificity of diagnoses of prodromal degenerative brain disease.

Functional cognitive disorders: identification and management

We review the various functional cognitive disorders (FCDs) – complaints about memory function or another cognitive process in the absence of relevant neuropathology. These are increasingly coming to the attention of psychiatrists and neurologists and FCD encompasses some newly recognised conditions in addition to classic types such as pseudodementia and psychogenic amnesia. The clinical features, neuropsychological findings and treatment are presented and discussed.

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Social Network Position Moderates the Relationship between Late-life Depressive Symptoms and Memory Differently in Men and Women

Late-life depression has been considered to be associated with memory deficits and hippocampal volume reduction. Considering that not all depression patients undergo the same amount of cognitive impairment or regional brain volume loss, moderating factors such as complex mental activity and social activity have been examined to assess whether these factors attenuate the detrimental impact of depressive symptoms on cognitive function and regional brain volume. However, the premise that a cognitively stimulating experience may modify the association between depressive symptoms and memory or hippocampal volume has not been investigated using social network data, which would reflect individuals' concrete characteristic of everyday social activity. In a social network, a brokerage position which connects two otherwise unconnected others demands mental and physical efforts. Using complete social network data in an entire village in South Korea, we examined whether opportunities for brokerage in social networks alter the negative association between depressive symptoms and episodic memory function or hippocampal volume in older adults. Initially, 125 participants were included in the analysis involving episodic memory function. Then, of which 65 participants completed the MRI scan, and were included in the subsequent analysis containing the hippocampal volume. Furthermore, we investigated the gender-specific effect of brokerage based on the previously reported gender difference in the effect of social networks. We found a gender-specific moderating effect of brokerage. For men, a large opportunity for brokerage weakened the negative association between depressive symptoms and memory performance and left hippocampal volume. In contrast, women showed that a large opportunity for brokerage was not beneficial for assuaging the impact of depressive symptoms on memory performance and hippocampal volume. In women, the opportunity for brokerage was positively associated with the detrimental impact of depressive symptoms on memory performance and hippocampal volume. Our findings suggest that occupying a bridging position in a social network may minimize the impact of depressive symptoms on memory function and hippocampal volume among older men, whereas the opposite holds true for older women.

Longitudinal outcomes of patients with pseudodementia: a systematic review

Depression and a number of other psychiatric conditions can impair cognition and give the appearance of neurodegenerative disease. Collectively, this group of disorders is known as 'pseudodementia' and are important to identify given their potential reversibility with treatment. Despite considerable interest historically, the longitudinal outcomes of patients with pseudodementia remain unclear. We conducted a systematic review of longitudinal studies of pseudodementia. Bibliographic databases were searched using a wide range of search terms. Two reviewers independently assessed papers for inclusion, rated study quality, and extracted data. The search identified 18 studies with follow-up varying from several weeks to 18 years. Overall, 284 patients were studied, including 238 patients with depression, 18 with conversion disorder, 14 with psychosis, and 11 with bipolar disorder. Irrespective of diagnosis, 33% developed irreversible dementia at follow-up, 53% no longer met criteria for dementia, and 15% were lost to follow-up. Considerable variability was identified, with younger age at baseline, but not follow-up duration, associated with better outcomes. ECT and pharmacological interventions were also reported to be beneficial, though findings were limited by the poor quality of the studies. Overall, the findings suggest that pseudodementia may confer an increased risk of irreversible dementia in older patients. The findings also indicate, however, that a significant proportion improve, while many remain burdened with their psychiatric condition, independent of organic dementia. The findings support the clinical value of the construct and the need for its re-examination in light of developments in neuroimaging, genomics, other investigative tools, and trial methodology.

Cognitive impairment in depression: recent advances and novel treatments

In the past, little or no attention was paid to cognitive disorders associated with depression (a condition sometimes termed pseudodementia). However, recent years have seen a growing interest in these changes, not only because of their high frequency in acute-stage depression, but also because they have been found to persist, as residual symptoms (in addition to affective and psychomotor ones), in many patients who respond well to antidepressant treatment. These cognitive symptoms seem to impact significantly not only on patients' functioning and quality of life, but also on the risk of recurrence of depression. Therefore, over the past decade, pharmacological research in this field has focused on the development of new agents able to counteract not only depressive symptoms, but also cognitive and functional ones. In this context, novel antidepressants with multimodal activity have emerged. This review considers the different issues, in terms of disease evolution, raised by the presence of cognitive disorders associated with depression and considers, particularly from the neurologist's perspective, the ways in which the clinical approach to cognitive symptoms, and their interpretation to diagnostic and therapeutic ends, have changed in recent years. Finally, after outlining the pharmacodynamics and pharmacokinetics of the first multimodal antidepressant, vortioxetine, it reports the main results obtained with the drug in depressed patients, also in consideration of the ever-increasing evidence on its different mechanisms of action in animal models.

Aberrant Default Mode Network Underlying the Cognitive Deficits in the Patients With Late-Onset Depression

Late-onset depression (LOD) is regarded as a risk factor or a prodrome of Alzheimer’s disease (AD). Moreover, LOD patients with cognitive deficits have the higher risk of subsequent AD. Thus, it is necessary to understand the neural underpinnings of cognitive deficits and its pathological implications in LOD. Consistent findings show that the default mode network (DMN) is an important and potentially useful brain network for the cognitive deficits in LOD patients. In recent years, genetics has been actively researched as a possible risk factor in the pathogenesis of LOD. So, in this review, we discuss the current research progress on the cognitive deficits and DMN in LOD through a combined view of brain network and genetics. We find that different structural and functional impairments of the DMN might be involved in the etiological mechanisms of different cognitive impairments in LOD patients.

Late-Life Depressive Symptoms and Lifetime History of Major Depression: Cognitive Deficits are Largely Due to Incipient Dementia rather than Depression

BACKGROUND

Late-life depression is frequently accompanied by cognitive impairments.

OBJECTIVE

Whether these impairments indicate a prodromal state of dementia, or are a symptomatic expression of depression per se is not well-studied.

METHODS

In a cohort of very old initially non-demented primary care patients (n = 2,709, mean age = 81.1 y), cognitive performance was compared between groups of participants with or without elevated depressive symptoms and with or without subsequent dementia using ANCOVA (adjusted for age, sex, and education). Logistic regression analyses were computed to predict subsequent dementia over up to six years of follow-up. The same analytical approach was performed for lifetime major depression.

RESULTS

Participants with elevated depressive symptoms without subsequent dementia showed only small to medium cognitive deficits. In contrast, participants with depressive symptoms with subsequent dementia showed medium to very large cognitive deficits. In adjusted logistic regression models, learning and memory deficits predicted the risk for subsequent dementia in participants with depressive symptoms. Participants with a lifetime history of major depression without subsequent dementia showed no cognitive deficits. However, in adjusted logistic regression models, learning and orientation deficits predicted the risk for subsequent dementia also in participants with lifetime major depression.

CONCLUSION

Marked cognitive impairments in old age depression should not be dismissed as "depressive pseudodementia", but require clinical attention as a possible sign of incipient dementia. Non-depressed elderly with a lifetime history of major depression, who remained free of dementia during follow-up, had largely normal cognitive performance.

Linking major depression and the neural substrates of associative processing

It has been proposed that mood correlates with the breadth of associative thinking. Here we set this hypothesis to the test in healthy and depressed individuals. Generating contextual associations engages a network of cortical regions including the parahippocampal cortex (PHC), retrosplenial complex, and medial prefrontal cortex. The link between mood, associative processing, and its underlying cortical infrastructure provides a promising avenue for elucidating the mechanisms underlying the cognitive impairments in major depressive disorder (MDD). The participants included 15 nonmedicated individuals with acute major depressive episodes and 15 healthy matched controls. In an fMRI experiment, participants viewed images of objects that were either strongly or weakly associated with a specific context (e.g., a beach chair vs. a water bottle) while rating the commonality of each object. Analyses were performed to examine the brain activation and structural differences between the groups. Consistent with our hypothesis, controls showed greater activation of the contextual associations network than did depressed participants. In addition, PHC structural volume was correlated with ruminative tendencies, and the volumes of the hippocampal subfields were significantly smaller in depressed participants. Surprisingly, depressed participants showed increased activity in the entorhinal cortex (ERC), as compared with controls. We integrated these findings within a mechanistic account linking mood and associative thinking and suggest directions for the future.

The Treatment of Disruptive Vocalization in Dementia (Behavioral and Psychological Symptoms of Dementia) With Electroconvulsive Therapy: A Case Series

OBJECTIVE

There is emerging evidence that electroconvulsive therapy (ECT) can help with the behavioral and psychological symptoms of dementia. One of the most distressing behavioral symptoms of dementia is disruptive vocalization. Previous small case series have suggested that antidepressants and ECT can be beneficial for this distressing condition. The aim of this study was to describe the successful use of ECT in treating 5 patients with disruptive vocalization.

METHODS

A retrospective chart review of 5 patients with dementia of mixed etiologies was conducted comparing pretreatment and posttreatment scores on the Cohen-Mansfield Agitation Inventory. All 5 patients had unsuccessful treatments with nonpharmacological methods and pharmacotherapy including antidepressants.

RESULTS

After completion of a series of ECT, the mean verbal agitation score decreased from 6.8 (95% confidence interval, 6.3-7.3) to 2.3 (95% confidence interval, 1.3-3.3), with both clinical and statistical significance (P < 0.001).

CONCLUSIONS

Although further research is needed, these findings support considering the use of ECT for disruptive vocalization in dementia.

Benefits, pitfalls, and future design of population-based registers in neurodegenerative disease

Population-based disease registers identify and characterize all cases of disease, including those that might otherwise be neglected. Prospective population-based registers in neurodegeneration are necessary to provide comprehensive data on the whole phenotypic spectrum and can guide planning of health services. With the exception of the rare disease amyotrophic lateral sclerosis, few complete population-based registers exist for neurodegenerative conditions. Incomplete ascertainment, limitations and uncertainty in diagnostic categorization, and failure to recognize sources of bias reduce the accuracy and usefulness of many registers. Common biases include population stratification, the use of prevalent rather than incident cases in earlier years, changes in disease understanding and diagnostic criteria, and changing demographics over time. Future registers are at risk of funding shortfalls and changes to privacy legislation. Notwithstanding, as heterogeneities of clinical phenotype and disease pathogenesis are increasingly recognized in the neurodegenerations, well-designed longitudinal population-based disease registers will be an essential requirement to complete clinical understanding of neurodegenerative diseases.

Links Between Chronic Illness and Late-Life Cognition: Evidence From Four Latin American Countries

Objectives: We explored the links between chronic diseases and cognitive ability using datasets of community-dwelling older adults from Brazil, Chile, Mexico, and Uruguay from the SABE (Health, Well-Being, and Aging) survey. Methods: Ordinary least squares (OLS), Tobit and linear probability models, adjusting for extensive health and socio-demographic factors, were implemented separately for men and women and complemented by a series of robustness checks. Results: We find a negative association between the number of chronic conditions and cognitive decline that has the following characteristics: (a) differs across gender, (b) increases with the number of chronic conditions, (c) is larger among those individuals in the bottom of the cognitive distribution, (d) and is different across types of chronic conditions. Discussion: These results suggest that returns from preventive policies to reduce cognitive decline would increase if they were targeted to seniors with chronic conditions and implemented before the impact from multiple comorbidities makes the cognitive decline too steep to be reversed.

The Effects of Vortioxetine on Cognitive Function in Patients with Major Depressive Disorder: A Meta-Analysis of Three Randomized Controlled Trials

BACKGROUND

Management of cognitive deficits in Major Depressive Disorder (MDD) remains an important unmet need. This meta-analysis evaluated the effects of vortioxetine on cognition in patients with MDD.

METHODS

Random effects meta-analysis was applied to three randomized, double-blind, placebo-controlled 8-week trials of vortioxetine (5-20mg/day) in MDD, and separately to two duloxetine-referenced trials. The primary outcome measure was change in Digit Symbol Substitution Test (DSST) score. Standardized effect sizes (SES) versus placebo (Cohen's d ) were used as input. Path analysis was employed to determine the extent to which changes in DSST were mediated independently of a change in Montgomery-Åsberg Depression Rating Scale (MADRS) score. Meta-analysis was applied to MADRS-adjusted and -unadjusted SES values. Changes on additional cognitive tests were evaluated (source studies only).

RESULTS

Before adjustment for MADRS, vortioxetine separated from placebo on DSST score (SES 0.25-0.48; nominal p < 0.05) in all individual trials, and statistically improved DSST performance versus placebo in meta-analyses of the three trials (SES = 0.35; p < 0.0001) and two duloxetine-referenced trials (SES = 0.26; p = 0.001). After adjustment for MADRS, vortioxetine maintained DSST improvement in one individual trial ( p = 0.001) and separation from placebo was maintained in meta-analyses of all three trials (SES = 0.24; p < 0.0001) and both duloxetine-referenced trials (SES 0.19; p = 0.01). Change in DSST with duloxetine failed to separate from placebo in individual trials and both meta-analyses. Change in DSST statistically favored vortioxetine versus duloxetine after MADRS adjustment (SES = 0.16; p = 0.04).

CONCLUSIONS

Vortioxetine, but not duloxetine, significantly improved cognition, independent of depressive symptoms. Vortioxetine represents an important treatment for MDD-related cognitive dysfunction.

Depression versus dementia: is this construct still relevant?

Cognitive impairment has long been identified as a component of late-life depression (LLD), and depressive symptoms are common in neurodegeneration. Depression may confer a greater risk of cognitive decline in a cognitively intact population and further cognitive decline in a mild cognitive impairment population compared with those without depression. Exploration of the link between cognitive impairment in LLD and the depressive features of neurodegeneration is an essential part of a diagnostic algorithm. In this review, we will discuss these links; we will address depressive symptoms as a risk factor for dementia and as a prodrome to dementia. We will review clinical subtypes and imaging markers as predictors of development of dementia in depressed patients and explore vascular etiologies. We will also explore LLD and dementia as a spectrum, rather than mutually exclusive diagnostic entities.

Pseudo-dementia: A neuropsychological review

Ever since Kiloh (1961)[2] coined the term pseudo-dementia, it has been used a little loosely for describing the cognitive deficits in depression, especially, which is found in old age. However, several diagnostic dilemmas persist regarding the nosological status of this condition. Teasing out these individual diagnostic problems is important not only for administering appropriate therapy, but also for preventing them from the unnecessary diagnostic assessments towards the other diagnoses. Thus, it is important to have a detailed knowledge of the cognitive or neuropsychological deficits in this condition. In this review, we start by addressing the important issue of diagnostic confusion between dementia and pseudo-dementia. Subsequently, we proceed by reviewing the present scientific literature on the cognitive deficits found in this clinical condition. For the sake of convenience, we will divide the cognitive deficits into:

Memory deficits

Executive function deficits and

Deficits in speech and language domains.

Finally, we will look at the progression of this condition to see the components of this condition, which can be actually called “Pseudo”.

Expanded C9ORF72 hexanucleotide repeat in depressive pseudodementia

IMPORTANCE

Expanded hexanucleotide repeats in C9ORF72 are a common genetic cause of frontotemporal dementia and amyotrophic lateral sclerosis. Repeat expansions have also been detected infrequently in other disorders, including Alzheimer disease, dementia with Lewy bodies, and parkinsonian disorders.

OBSERVATIONS

A consecutive series of 31 cases from the brain bank for neurodegenerative disorders at Mayo Clinic was screened to assess the incidence of the expanded C9ORF72 repeat in cases of depressive pseudodementia. The presence of the hexanucleotide repeat was established using immunohistochemistry with a highly disease-specific antibody (C9RANT), and was further validated in carriers using repeat-primed polymerase chain reaction and Southern blotting. Two individuals harbored the C9ORF72 repeat expansion. Both patients were men with refractory depression. One patient experienced drug-induced parkinsonism and sudden-onset dementia, while the other patient had a more insidious disease course suspected to be Alzheimer disease.

CONCLUSIONS AND RELEVANCE

This report increases the range of clinicopathologic presentations of C9ORF72 expanded hexanucleotide repeat to include psychiatric disorders such as depressive pseudodementia.

A comparison of the cornell scale for depression in dementia and the Montgomery-Aasberg depression rating scale in a memory clinic population

BACKGROUND

The aim of this study was to explore the correlation between the Cornell Scale for Depression in Dementia (CSDD) and the Montgomery-Aasberg Depression Rating Scale (MADRS) among memory clinic patients.

METHODS

The CSDD (based on an interview with the caregiver) and the MADRS (based on the patient's opinion) were filled in independently of each other among 520 patients. Principal component and correlation analyses were performed.

RESULTS

The mean score of the CSDD was 7.6 (SD: 6.0), and the mean MADRS score was 9.7 (SD: 6.7). The correlation between the two scales was 0.36 for the whole group, 0.22 in the group with dementia and 0.48 for those without dementia, respectively. Principal component analyses revealed four factors for the CSDD and two factors for the MADRS.

CONCLUSIONS

Using two different sources of information, we found a poor correlation between the two scales. We suggest that evaluation of depression among memory clinic patients should be done by interviewing both the patient and the caregiver.

rTMS as a Treatment of Alzheimer's Disease with and without Comorbidity of Depression: A Review

With an ever-increasing population of Alzheimer's disease (AD) patients worldwide, a noninvasive treatment for AD is needed. In this paper, the application of repetitive transcranial magnetic stimulus (rTMS) as a treatment for patients with probable AD is compared to the application of rTMS as a treatment for depression. Comorbidity of depression and dementia is discussed, as well as possible links between the two diseases. The possible confounding antidepressant effects of rTMS on cognitive improvements in AD patients are discussed.

Major depressive disorder with psychotic features may lead to misdiagnosis of dementia: a case report and review of the literature

Major depressive disorder (MDD) with psychotic features is relatively frequent in patients with greater depressive symptom severity and is associated with a poorer course of illness and greater functional impairment than MDD without psychotic features. Multiple studies have found that patients with psychotic mood disorders demonstrate significantly poorer cognitive performance in a variety of areas than those with nonpsychotic mood disorders. The Mini Mental State Examination (MMSE) and the Dementia Rating Scale, Second Edition (DRS-2) are widely used to measure cognitive functions in research on MDD with psychotic features. Established total raw score cut-offs of 24 on the MMSE and 137 on the DRS-2 in published manuals suggest possible global cognitive impairment and dementia, respectively. Limited research is available on these suggested cut-offs for patients with MDD with psychotic features. We document the therapeutic benefit of electroconvulsive therapy (ECT), which is usually associated with short-term cognitive impairment, in a 68-year-old woman with psychotic depression whose MMSE and DRS-2 scores initially suggested possible global cognitive impairment and dementia. Over the course of four ECT treatments, the patient's MMSE scores progressively increased. After the second ECT treatment, the patient no longer met criteria for global cognitive impairment. With each treatment, depression severity, measured by the 24-item Hamilton Rating Scale for Depression, improved sequentially. Thus, the suggested cut-off scores for the MMSE and the DRS-2 in patients with MDD with psychotic features may in some cases produce false-positive indications of dementia.

Neuropsychological safety of nucleus accumbens deep brain stimulation for major depression: effects of 12-month stimulation

OBJECTIVES

Deep brain stimulation (DBS) to the nucleus accumbens (NAcc-DBS) has antidepressant effects in patients suffering from treatment-resistant depression (TRD). However, limited information exists regarding the impact of NAcc-DBS on cognitive functioning. The aim of this study was to examine whether NAcc-DBS in patients with TRD has any cognitive effects.

METHODS

A comprehensive neuropsychological battery was administered to 10 patients with TRD before onset of bilateral NAcc-DBS and after 1 year of DBS stimulation. Neuropsychological testing covered the domains of attention, learning and memory, executive functions, visual perception, and language. Performance was analyzed at baseline and after 1 year of continuous DBS.

RESULTS

No evidence was found for cognitive decline following NAcc-DBS comparing test results after 1 year of NAcc-DBS with baseline. However, significantly improved cognitive performance on tests of attention, learning and memory, executive functions and visual perception was found. In addition, there was a general trend towards cognitive enhancement from below average to average performance. These procognitive effects were independent of the antidepressant effects of NAcc-DBS or changes in NAcc-DBS parameters.

CONCLUSIONS

These results not only support cognitive safety of NAcc-DBS but also stress its beneficial role in augmenting cognitive performance in patients with TRD.

Mild Cognitive Impairment in the Elderly

The article reviews the relationship between depressive symptoms and mild cognitive impairment (MCI). Evidence bearing on this relation comes from clinical findings, neuroimaging, and cerebrospinal fluid markers. Depression in elderly people is associated with a higher occurrence of cognitive impairment, whereas the decline of cognitive functions over time seems to be a predictor of the development of dementia. Further symptoms predicting a high risk of progression from MCI to dementia are anxiety, restlessness, and low awareness of cognitive malfunction. There are controversies in the literature, however, about the connections among vascular brain lesions, depression, and MCI. Frontal and temporal brain regions seem to be at the core of functional changes in MCI patients. Several studies of cerebrospinal fluid point out the role of tau protein in predicting the outcome of MCI over time. In conclusion, diagnosis of MCI demands a complex assessment. MCI patients with and without depression need careful follow-up investigations.

The diagnostic challenge of psychiatric symptoms in neurodegenerative disease: rates of and risk factors for prior psychiatric diagnosis in patients with early neurodegenerative disease

OBJECTIVE

To identify rates of and risk factors for psychiatric diagnosis preceding the diagnosis of neurodegenerative disease.

METHOD

Systematic, retrospective, blinded chart review was performed of 252 patients with a neurodegenerative disease diagnosis seen in our specialty clinic between 1999 and 2008. Neurodegenerative disease diagnoses included behavioral-variant frontotemporal dementia (n = 69), semantic dementia (n = 41), and progressive nonfluent aphasia (n = 17) (all meeting Neary research criteria); Alzheimer's disease (n = 65) (National Institute of Neurologic and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association research criteria); corticobasal degeneration (n = 25) (Boxer research criteria); progressive supranuclear palsy (n = 15) (Litvan research criteria); and amyotrophic lateral sclerosis (n = 20) (El Escorial research criteria). Reviewers remained blinded to each patient's final neurodegenerative disease diagnosis while reviewing charts. Extensive caregiver interviews were conducted to ensure accurate and reliable diagnostic histories. For each patient, we recorded history of psychiatric diagnosis, family psychiatric and neurologic history, age at symptom onset, and demographic information.

RESULTS

A total of 28.2% of patients with a neurodegenerative disease received a prior psychiatric diagnosis. Depression was the most common psychiatric diagnosis in all groups. Behavioral-variant frontotemporal dementia patients received a prior psychiatric diagnosis significantly more often (50.7%; P < .001) than patients with Alzheimer's disease (23.1%), semantic dementia (24.4%), or progressive nonfluent aphasia (11.8%) and were more likely to receive diagnoses of bipolar disorder or schizophrenia than were patients with other neurodegenerative diseases (P < .001). Younger age (P < .001), higher education (P < .05), and a family history of psychiatric illness (P < .05) increased the rate of prior psychiatric diagnosis in patients with behavioral-variant frontotemporal dementia. Cognitive, behavioral, and emotional characteristics did not distinguish patients who did or did not receive a prior psychiatric diagnosis.

CONCLUSIONS

Neurodegenerative disease is often misclassified as psychiatric disease, with behavioral-variant frontotemporal dementia patients at highest risk. While this study cannot rule out the possibility that psychiatric disease is an independent risk factor for neurodegenerative disease, when patients with neurodegenerative disease are initially classified with psychiatric disease, the patient may receive delayed, inappropriate treatment and be subject to increased distress. Physicians should consider referring mid- to late-life patients with new-onset neuropsychiatric symptoms for neurodegenerative disease evaluation.

[Recurrent depression in the elderly: what cognitive prognosis?]

Depressive disorders are currently the expression of psychological and neurological vulnerabilities, which may be induced or increased by depression. Recurrence or chronic course of depressive episodes is more frequently associated with short-term or persistent cognitive deficits, and may increase the risk of dementia. This raises the question of shared pathophysiological factors. It is of major importance to assess the evolution of cognitive functioning after late-onset depressive episodes or after multiple episodes. This is one of the main reasons to prevent recurrence of depression, especially in the second part of life.

Neuromodulation approaches for the treatment of major depression: challenges and recommendations from a working group meeting

The use of neuromodulation as a treatment for major depressive disorder (MDD) has recently attracted renewed interest due to development of other non-pharmacological therapies besides electroconvulsive therapy (ECT) such as transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), deep brain stimulation (DBS), and vagus nerve stimulation (VNS). METHOD: We convened a working group of researchers to discuss the updates and key challenges of neuromodulation use for the treatment of MDD. RESULTS: The state-of-art of neuromodulation techniques was reviewed and discussed in four sections: [1] epidemiology and pathophysiology of MDD; [2] a comprehensive overview of the neuromodulation techniques; [3] using neuromodulation techniques in MDD associated with non-psychiatric conditions; [4] the main challenges of neuromodulation research and alternatives to overcome them. DISCUSSION: ECT is the first-line treatment for severe depression. TMS and tDCS are strategies with a relative benign profile of side effects; however, while TMS effects are comparable to antidepressant drugs for treating MDD; further research is needed to establish the role of tDCS. DBS and VNS are invasive strategies with a possible role in treatment-resistant depression. In summary, MDD is a chronic and incapacitating condition with a high prevalence; therefore clinicians should consider all the treatment options including invasive and non-invasive neuromodulation approaches.

The emerging modern face of mood disorders: a didactic editorial with a detailed presentation of data and definitions

The present work represents a detailed description of our current understanding and knowledge of the epidemiology, etiopathogenesis and clinical manifestations of mood disorders, their comorbidity and overlap, and the effect of variables such as gender and age. This review article is largely based on the 'Mood disorders' chapter of the Wikibooks Textbook of Psychiatry http://en.wikibooks.org/wiki/Textbook_of_Psychiatry/Mood_Disorders.

Depression, extrapyramidal symptoms, dementia and an unexpected outcome: a case report

Introduction

The diagnosis of Parkinson's disease is mainly clinical. DaT SCAN may help in difficult cases. Depression is also a clinical diagnosis and is common and persistent symptom in Parkinson's disease. Dementia is very often in Parkinson's disease, but usually not at the first stages. The treatment of each of the above symptoms is difficult and a lot of times individualized.

Case Presentation

Female 64 years old patient with history of hypothyroidism, depression and anxiety disorder was examined at outpatient Memory and Dementia clinic of 3^rd Department of Neurology. The patient's major problems were functional and cognitive decline, severe extrapyramidal symptoms and depression. According to UKPDS Brain Bank criteria the patient had bradykinesia, muscular rigidity, postural instability and rest tremor present with unilateral onset of the symptoms affecting left side most and progressive course. The modified Hoehn and Yahr scale was 3: mild to moderate bilateral disease; some postural instability; physically independent. The symptoms remained during nine months follow up, despite the pharmaceutical treatment. Nine months later, the patient made an attempt to suicide. Firstly, she was transferred to intensive care department with 2^nd degree burns and respiratory problems, then she was hospitalized at the Burn Unit and afterwards at the Psychiatric clinic. One month later the patient had no depression, a clear reduction of the extrapyramidal symptoms, functional and cognitive improvement.

Conclusion

An astonishing improvement occurred after the threat of life. Two years after the attempt to suicide, the depressive symptoms remain in remission and functional and cognitive status is normal. The extrapyramidal symptoms have disappeared.

Relation between neuritic plaques and depressive state in Alzheimer's disease

Meynen G, Van Stralen H, Smit JH, Kamphorst W, Swaab DF, Hoogendijk WJG. Relation between neuritic plaques and depressive state in Alzheimer's disease.

BACKGROUND

To investigate for the first time in a prospective study the relationship between depressive state and the neuropathological hallmarks of Alzheimer's disease, using a scale for depressive symptoms in dementia, while controlling for clinical severity of dementia.

METHOD

Within the framework of a prospective longitudinal study of depression in Alzheimer's disease, patients with dementia underwent a clinical evaluation every six months during the last years of their lives, using the Cornell scale for depression in dementia to assess depressive symptoms and using the Functional Assessment Staging scale to control for clinical severity of dementia. The brains of 43 Alzheimer patients were obtained. The last clinical evaluations prior to death together with post-mortem neuropathology measures were analysed.

RESULTS

We found a correlation between the Cornell scores and the sum score for the density of neuritic plaques in the entire cortex (p = 0.027), and even stronger in the temporal cortex (p = 0.012). The observed correlations were independent of sex, age of death, clinical dementia severity and duration of Alzheimer's disease.

CONCLUSIONS

This study shows a positive relationship between depressive state at time of death and the presence of neuritic plaques in Alzheimer's disease, which is independent of the clinical severity of dementia.

Hypothalamic vasopressin and oxytocin mRNA expression in relation to depressive state in Alzheimer's disease: a difference with major depressive disorder

Arginine vasopressin (AVP) and oxytocin (OXT), produced in the hypothalamic paraventricular (PVN) and supraoptic nucleus (SON), are considered to be involved in the pathophysiology of major depressive disorder (MDD). The objective of this study was to determine, for the first time, the relationship between AVP and OXT gene expression and depressive state in Alzheimer's disease (AD). Post-mortem brain tissue was obtained from six control subjects, and from a prospectively studied cohort of 23 AD patients, using the DSM-IIIR and the Cornell Scale for Depression in Dementia to determine depression diagnosis and severity. The amount of AVP and OXT mRNA was determined by in situ hybridisation. AD patients did not differ from controls with respect to the amount of AVP or OXT mRNA in the PVN or SON. Also, no differences were found between depressed and nondepressed AD patients and no relationship was found between the depression severity and AVP or OXT mRNA expression. The results indicate that AVP and OXT gene expression in the PVN and SON is unchanged in depressed AD patients compared to nondepressed AD patients. This is in contrast with the enhanced AVP gene expression in MDD, suggesting a difference in pathophysiology between MDD and depression in AD.

Depression and dementia

Depression and cognitive impairment are both common conditions in old age, and frequently occur together. However, accurate figures of the co-occurrence are not available. The inter-relationship between the two clinical entities is still complex and not well understood. Clearly depression can be a psychological reaction to cognitive decline, and thus may also appear as an early symptom in dementing individuals. However, recent data suggest that depression, and in particularly late-life depression, can also be a risk factor for Alzheimer's disease (AD). The relationship between the two clinical entities should be seen in view of observations of white matter changes both in AD and in depression. Since these white matter changes are thought to frequently reflect vascular changes, the concept of "vascular depression" has been advanced. Vascular changes in the brain occur commonly in demented individuals and conversely depression is frequent co-occurrence in vascular disease. Additionally neurotransmitter loss may occur in both, particularly monoaminergic disturbances which is characteristic of depression but may occur also in AD. The same is true for hippocampal atrophy, which is characteristic of AD but has also been described in depression. Here we review the complex relationships between dementia and depression and suggest that excessive release of corticosteroids may have a neurotoxic effects.

A review of the cognitive effects of electroconvulsive therapy in older adults

OBJECTIVE

To review studies that examined the impact of electroconvulsive therapy (ECT) on cognitive functioning in depressed older people.

METHODS

Studies were systematically retrieved using PsychINFO and MEDLINE, with additional articles sourced from lists of references. Given our aged-care focus, study participants had a minimum mean age of 60 years, with no single participant younger than 50 years.

RESULTS

Twenty-seven studies met our criteria. Apart from evidence of interictal slowing of information processing speed, there were mixed results with regard to the impact of ECT on other cognitive domains. Factors contributing to this variability in results include the lack of discrimination between unilateral, bilateral, or mixed electrode placement; the inclusion of patients with dementia; the small sample sizes; and the use of tests insensitive to subtle cognitive changes.

CONCLUSIONS

The effect of ECT in elderly recipients' cognition remains unclear, and further research with more critically selected methods is required. In the meantime, we recommend that clinicians regularly administer brief focused cognitive tests before, during, and after treatment to monitor progress.