Randomized double-blind placebo-controlled donepezil augmentation in antidepressant-treated elderly patients with depression and cognitive impairment: a pilot study

Pharmacological targeting of cognitive impairment in depression: recent developments and challenges in human clinical research

Impaired cognition is often overlooked in the clinical management of depression, despite its association with poor psychosocial functioning and reduced clinical engagement. There is an outstanding need for new treatments to address this unmet clinical need, highlighted by our consultations with individuals with lived experience of depression. Here we consider the evidence to support different pharmacological approaches for the treatment of impaired cognition in individuals with depression, including treatments that influence primary neurotransmission directly as well as novel targets such as neurosteroid modulation. We also consider potential methodological challenges in establishing a strong evidence base in this area, including the need to disentangle direct effects of treatment on cognition from more generalised symptomatic improvement and the identification of sensitive, reliable and objective measures of cognition.

Effectiveness and Safety of the Korean Medicine Senior Health Promotion Program Using Herbal Medicine and Acupuncture for Mild Cognitive Impairment: A Retrospective Study of 500 Patients in Seoul, Korea

BACKGROUND

The management of mild cognitive impairment (MCI) is becoming increasingly important. The Korean Medicine Senior Health Promotion Program (KSHPP) was developed in 2016, and it has been in use to date. This study aimed to assess the effectiveness of KSHPP using herbal medicine and acupuncture for treating MCI and the safety of herbal medicine using liver and renal function tests.

METHODS

We retrospectively reviewed the medical records of the participants with MCI. We assessed the Korean version of the Montreal Cognitive Assessment (MoCA-K), the Mini-Mental State Examination-Dementia Screening (MMSE-DS), and the Geriatric Depression Scale Short Form-Korea version (GDSSF-K) scores before and after KSHPP to determine its effectiveness. To evaluate its safety, the liver and renal function tests were conducted before and after herbal treatment.

RESULTS

We enrolled 1002 participants, and 500 participants satisfied the inclusion criteria. Of 500 patients, 364 (72.8%) were depressed and 136 (27.2%) were not. The mean MoCA-K score significantly increased by 2.77 for the entire sample and 3.22 for the depressed sample (all P < 0.0001). The mean MMSE-DS score significantly increased by 2.19 for the entire sample and 2.51 for the depressed sample (all P < 0.0001); the mean GDSSF-K score significantly decreased by 1.73 for the entire sample and 2.68 for the depressed sample (all P < 0.0001).

CONCLUSIONS

Our findings suggest that Korean medicine interventions can improve cognitive function and depression symptoms in patients with MCI. In addition, the results of the liver and renal function tests were analyzed as surrogate outcomes to assess the safety of herbal medicine. Based on these results, we expect that Korean medicine interventions can promote the cognitive and mental health of seniors. However, as there were several study limitations, particularly study design, practice effect, and short follow-up, these results must be interpreted with caution. We need a further long-term study with a rigorous design to retain confidence in the effectiveness and safety of KSHPP.

Depression in Alzheimer's Disease: A Delphi Consensus on Etiology, Risk Factors, and Clinical Management

Background: Alzheimer's disease (AD) and other forms of dementia are among the most common causes of disability in the elderly. Dementia is often accompanied by depression, but specific diagnostic criteria and treatment approaches are still lacking. This study aimed to gather expert opinions on dementia and depressed patient management to reduce heterogeneity in everyday practice. Methods: Prospective, multicenter, 2-round Modified Delphi survey with 53 questions regarding risk factors (11), signs and symptoms (7), diagnosis (8), and treatment (27) of depression in dementia, with a particular focus on AD. The questionnaire was completed by a panel of 37 expert physicians in neurodegenerative diseases (19 neurologists, 17 psychiatrists, and 1 geriatrician). Results: Consensus was achieved in 40 (75.5%) of the items: agreement in 33 (62.3%) and disagreement in 7 (13.2%) of them. Among the most relevant findings, depression in the elderly was considered an early sign (prodromal) and/or a dementia risk factor, so routine cognitive check-ups in depressed patients should be adopted, aided by clinical scales and information from relatives. Careful interpretation of neuropsychological assessment must be carried out in patients with depression as it can undermine cognitive outcomes. As agreed, depression in early AD is characterized by somatic symptoms and can be differentiated from apathy by the presence of sadness, depressive thoughts and early-morning awakening. In later-phases, symptoms of depression would include sleep-wake cycle reversal, aggressive behavior, and agitation. Regardless of the stage of dementia, depression would accelerate its course, whereas antidepressants would have the opposite effect. Those that improve cognitive function and/or have a dual or multimodal mode of action were preferred: Duloxetine, venlafaxine/desvenlafaxine, vortioxetine, tianeptine, and mirtazapine. Although antidepressants may be less effective than in cognitively healthy patients, neither dosage nor treatment duration should differ. Anti-dementia cholinesterase inhibitors may have a synergistic effect with antidepressants. Exercise and psychological interventions should not be applied alone before any pharmacological treatment, yet they do play a part in improving depressive symptoms in demented patients. Conclusions: This study sheds light on several unresolved clinical challenges regarding depression in dementia patients. Further studies and specific recommendations for this comorbid patient population are still needed.

Internet-Based Cognitive Behavior Therapy Only for the Young? A Secondary Analysis of a Randomized Controlled Trial of Depression Treatment

BACKGROUND

Late-life depression is a major public health concern, driving the development of complementary treatment options. This study investigates the effectiveness and acceptability of internet-based Cognitive Behavioral Therapy (iCBT) in older individuals (60+ years) compared to younger age groups.

MATERIALS AND METHODS

Secondary analysis of a cluster-randomized controlled trial with 647 (18-82 years; mean 43.9) mild to moderately severe depressed primary care patients receiving either iCBT + treatment as usual (TAU) or TAU alone. Severity of depression was measured by the Beck Depression Inventory (BDI-II) at baseline, 6 weeks and 6 months. Intention-to-treat analysis in three age groups (18-39 years, n = 264; 40-59 years, n = 300; 60+ years, n = 83) was performed, using mixed-effects regression models to quantify treatment effect.

RESULTS

No age differences in the effectiveness of iCBT were found. Patients in the intervention group consistently showed a greater reduction in depression severity than controls in all three age groups and at both follow-ups. Effect sizes ranged from d = 0.30 (40-59 years, 6 weeks) to d = 1.91 (60+ years, 6 months). Uptake of the intervention was banded around 70% with no differences between age groups (χ² = 0.18, p = .915). The mean number of completed modules increased with age (χ² = 18.99, p = .040).

DISCUSSION

iCBT is equally effective in both younger and older individuals, thus providing a valuable complementary element of routine late-life depression care.

CLINICAL TRIAL REGISTRATION

DRKS-ID: DRKS00005075 https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00005075.

Neurological Changes and Depression: 2020 Update

This article covers current research on the relationship between depression and cognitive impairment in older adults. First, it approaches the clinical assessment of late-life depression and comorbid cognitive impairment. Cognitive risk factors for suicide are discussed. Research is then provided on neuropsychological changes associated with depression, discussing subjective cognitive impairment, mild cognitive impairment, and dementia profiles. In addition, literature regarding neuroimaging and biomarker findings in depressed older adults is presented. Finally, therapeutic models for treatment of late-life depression are discussed, including psychotherapy models, holistic treatments, pharmacologic approaches, and brain stimulation therapies.

Management of Late-Life Depression

Depression is a common disorder in late life that is associated with poor quality of life, increased disability, and increased all-cause mortality. Rates of completed suicide are the highest in older depressed men compared with any other age group. In this age group, depression is often concurrent with medical illness and it can aggravate the course of medical illness. Cognitive impairment is frequently present and may be the result of the depression itself or may be the consequence of a neurodegenerative disorder such as Alzheimer's disease. Evidence-based psychotherapies, antidepressants, and somatic treatments such as electroconvulsive therapy are employed in the treatment of older depressed adults. Treatment may be complicated by the presence of cognitive impairment, other comorbid medical disorders, and medications used to treat these disorders. Certain safety issues such as increased bleeding risk, hyponatremia, decreased bone density and falls may be associated with antidepressant treatment, may be more common in older depressed adults, and their consequences may be more severe in late life. These risks, however, need to be weighed against the hazards of untreated depression. With appropriate care, most older depressed patients can be successfully treated and a positive outcome can have a significant effect on the patient's quality of life.

Donepezil Treatment in Patients With Depression and Cognitive Impairment on Stable Antidepressant Treatment: A Randomized Controlled Trial

OBJECTIVE

Depression and cognitive impairment are often comorbid in older adults, but optimal treatment strategies remain unclear. In a two-site study, the efficacy and safety of add-on donepezil versus placebo were compared in depressed patients with cognitive impairment receiving stable antidepressant treatment.

METHODS

A randomized, double-blind, placebo-controlled trial was conducted in older adults with depression and cognitive impairment (https://clinicaltrials.gov/ct2/show/NCT01658228; NCT01658228). Patients received open-label antidepressant treatment for 16 weeks, initially with citalopram and then with venlafaxine, if needed, followed by random assignment to add-on donepezil 5-10 mg daily or placebo for another 62 weeks. Outcome measures were neuropsychological test performance (Alzheimer's Disease Assessment Scale-Cognitive subscale [ADAS-Cog] and Selective Reminding Test [SRT] total immediate recall) and instrumental activities of daily living (Functional Activities Questionnaire).

RESULTS

Of 81 patients who signed informed consent, 79 patients completed the baseline evaluation. Open antidepressant treatment was associated with improvement in depression in 63.93% responders by week 16. In the randomized trial, there were no treatment group differences between donepezil and placebo on dementia conversion rates, ADAS-Cog, SRT total immediate recall, or FAQ. Neither baseline cognitive impairment severity nor apolipoprotein E e4 genotype influenced donepezil efficacy. Donepezil was associated with more adverse effects than placebo.

CONCLUSION

The results do not support adjunctive off-label cholinesterase inhibitor treatment in patients with depression and cognitive impairment. The findings highlight the need to prioritize discovery of novel treatments for this highly prevalent population with comorbid illnesses.

Antidepressants for treating depression in dementia

BACKGROUND

The use of antidepressants in dementia accompanied by depressive symptoms is widespread, but their clinical efficacy is uncertain. This review updates an earlier version, first published in 2002.

OBJECTIVES

To determine the efficacy and safety of any type of antidepressant for patients who have been diagnosed as having dementia of any type and depression as defined by recognised criteria.

SEARCH METHODS

We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group's Specialised Register, on 16 August 2017. ALOIS contains information on trials retrieved from databases and from a number of trial registers and grey literature sources.

SELECTION CRITERIA

We included all relevant double-blind, randomised trials comparing any antidepressant drug with placebo, for patients diagnosed as having dementia and depression.

DATA COLLECTION AND ANALYSIS

Two review authors selected studies for inclusion and extracted data independently. We assessed risk of bias in the included studies using the Cochrane 'Risk of bias' tool. Where clinically appropriate, we pooled data for treatment periods up to three months and from three to nine months. We used GRADE methods to assess the overall quality of the evidence.

MAIN RESULTS

We included ten studies with a total of 1592 patients. Eight included studies reported sufficiently detailed results to enter into analyses related to antidepressant efficacy. We split one study which included two different antidepressants and therefore had nine groups of patients treated with antidepressants compared with nine groups receiving placebo treatment. Information needed to make 'Risk of bias' judgements was often missing.We found high-quality evidence of little or no difference in scores on depression symptom rating scales between the antidepressant and placebo treated groups after 6 to 13 weeks (standardised mean difference (SMD) -0.10, 95% confidence interval (CI) -0.26 to 0.06; 614 participants; 8 studies). There was probably also little or no difference between groups after six to nine months (mean difference (MD) 0.59 point, 95% CI -1.12 to 2.3, 357 participants; 2 studies; moderate-quality evidence). The evidence on response rates at 12 weeks was of low quality, and imprecision in the result meant we were uncertain of any effect of antidepressants (antidepressant: 49.1%, placebo: 37.7%; odds ratio (OR) 1.71, 95% CI 0.80 to 3.67; 116 participants; 3 studies). However, the remission rate was probably higher in the antidepressant group than the placebo group (antidepressant: 40%, placebo: 21.7%; OR 2.57, 95% CI 1.44 to 4.59; 240 participants; 4 studies; moderate-quality evidence). The largest of these studies continued for another 12 weeks, but because of imprecision of the result we could not be sure of any effect of antidepressants on remission rates after 24 weeks. There was evidence of no effect of antidepressants on performance of activities of daily living at weeks 6 to 13 (SMD -0.05, 95% CI -0.36 to 0.25; 173 participants; 4 studies; high-quality evidence) and probably also little or no effect on cognition (MD 0.33 point on the Mini-Mental State Examination, 95% CI -1.31 to 1.96; 194 participants; 6 studies; moderate-quality evidence).Participants on antidepressants were probably more likely to drop out of treatment than those on placebo over 6 to 13 weeks (OR 1.51, 95% CI 1.07 to 2.14; 836 participants; 9 studies). The meta-analysis of the number of participants suffering at least one adverse event showed a significant difference in favour of placebo (antidepressant: 49.2%, placebo: 38.4%; OR 1.55, 95% CI 1.21 to 1.98, 1073 participants; 3 studies), as did the analyses for participants suffering one event of dry mouth (antidepressant: 19.6%, placebo: 13.3%; OR 1.80, 95% CI 1.23 to 2.63, 1044 participants; 5 studies), and one event of dizziness (antidepressant: 19.2%, placebo: 12.5%; OR 2.00, 95% CI 1.34 to 2.98, 1044 participants; 5 studies). Heterogeneity in the way adverse events were reported in studies presented a major difficulty for meta-analysis, but there was some evidence that antidepressant treatment causes more adverse effects than placebo treatment does.

AUTHORS' CONCLUSIONS

The available evidence is of variable quality and does not provide strong support for the efficacy of antidepressants for treating depression in dementia, especially beyond 12 weeks. On the only measure of efficacy for which we had high-quality evidence (depression rating scale scores), antidepressants showed little or no effect. The evidence on remission rates favoured antidepressants but was of moderate quality, so future research may find a different result. There was insufficient evidence to draw conclusions about individual antidepressant drugs or about subtypes of dementia or depression. There is some evidence that antidepressant treatment may cause adverse events.

Donepezil may reduce the risk of comorbidities in patients with Alzheimer's disease: A large-scale matched case-control analysis in Japan

Introduction

Few studies have focused on the association between donepezil and physical comorbid conditions in Alzheimer's disease patients.

Methods

We investigated the association between donepezil prescription and the occurrences of comorbidities in Alzheimer's disease patients, by using an electronic medical records database which contains case-based information on approximately three million patients from more than 60 hospitals across Japan.

Results

Nine thousand seven hundred forty-nine patients had at least one diagnosis of Alzheimer's disease between 2001 and 2015. To test the robustness of the results, we used a risk set sampling method, and the matched cohorts based on age, sex, comorbidity level, and duration of illness consisted of 1406 cases and an equal number of controls. From the multivariate logistic regression analysis adjusted for covariance, less occurrence of physical comorbidities was associated with donepezil prescription in the matched cohort.

Discussion

Although the mechanisms are unknown, donepezil may have positive effects on both cognition and physical status.

Neurologic Changes and Depression

This article covers current research on the relationship between depression and cognitive impairment in older adults. First, it approaches the clinical assessment of late-life depression and comorbid cognitive impairment. Cognitive risk factors for suicide are discussed. Research is then provided on neuropsychological changes associated with depression, discussing subjective cognitive impairment, mild cognitive impairment, and dementia profiles. Additionally, literature regarding neuroimaging and biomarker findings in depressed older adults is presented. Finally, therapeutic models for treatment of late-life depression are also discussed, including psychotherapy models, holistic treatments, pharmacologic approaches, and brain-stimulation therapies.

Treatment of neurocognitive symptoms in unipolar depression: A systematic review and future perspectives

BACKGROUND

Cognitive symptoms in Major Depressive Disorder (MDD) are persistent and commonly entail neurocognitive impairment and a decline in quality of life. This systematic review gathers the current scientific evidence on therapeutic strategies for neuropsychological impairment in MDD.

METHOD

A systematic search on PubMed, PsycINFO and Clinicaltrials.gov was carried out on December 2016 according to PRISMA using Boolean terms to identify interventions for the treatment of cognitive dysfunction in MDD. Only English-written articles providing original data and focusing in adults with MDD were included with no time restrictions.

RESULTS

A total of 95 studies reporting data on 40 pharmacological and non-pharmacological interventions were included. Interventions were grouped into the following categories: 1) Pharmacological Therapies (antidepressants, stimulants, compounds acting on NMDA receptors, compounds acting on the cholinergic system, compounds showing anti-inflammatory or antioxidant properties, other mechanisms of action), 2) Physical Therapies and 3) Psychological Therapies, 4) Exercise. There are some promising compounds showing a positive impact on cognitive symptoms including vortioxetine, lisdexamfetamine or erythropoietin.

LIMITATIONS

The studies included showed significant methodological differences in heterogeneous samples. The lack of a standardized neuropsychological battery makes comparisons between studies difficult.

CONCLUSION

Current evidence is not sufficient to widely recommend the use of procognitive treatments in MDD although promising results are coming to light.

Systematic review of randomized controlled trials of candidate treatments for cognitive impairment in depression and methodological challenges in the field

Cognitive impairment is a core feature of Major Depressive Disorder (MDD) but treatments targeting cognition are lacking. Numerous pre-clinical and clinical studies have investigated potential cognition treatments, but overall the evidence is conflicting. We conducted a systematic search following the PRISMA guidelines on PubMed and PsychInfo to evaluate the extant evidence and methodological challenges in randomized controlled trials (RCTs) of biological, psychological and behavioural candidate treatments targeting cognition in MDD. Inclusion criteria were RCTs with a placebo control assessing potential pro-cognitive effects of candidate treatments in MDD. Two independent authors reviewed the studies and assessed their risk of bias with the Cochrane Collaboration׳s Risk of Bias tool. Twenty-eight eligible studies (24 biological and four psychological or behavioural studies) were identified. Cognition was the primary treatment target in ten (36%) trials and an additional treatment outcome together with mood symptoms in 18 (64%) trials. The risk of bias was high or unclear in 93% of trials due to potential selective outcome reporting or 'pseudospecificity' (unspecific cognitive improvement due to reduced depression severity), and/or insufficient details on how the allocation sequence was generated or how blinding was maintained. Several promising treatments were identified, including vortioxetine, erythropoietin, transcranial direct current stimulation and cognitive remediation. However, several common methodological challenges may impede advances in the field. In particular, future trials should select one cognitive composite score as primary outcome, screen for cognitive impairment before inclusion of participants and address 'pseudospecificity' issues. Together, these strategies may improve the success of future cognition trials in MDD.

Combined treatment with memantine/es-citalopram for older depressed patients with cognitive impairment: a pilot study

OBJECTIVE

The objective of the study is to assess combined antidepressant and memantine treatment in older patients presenting with depression and cognitive impairment.

METHODS

Thirty-five depressed patients with cognitive impairment participated in this open-label pilot study. We evaluated whether, over a 48-week period, combined antidepressant (primarily es-citalopram) and memantine treatment was effective in the treatment of cognitive impairment and depression. Neuropsychological testing was performed, and antidepressant response monitored at baseline and at the 12, 24, and 48-week time points.

RESULTS

Treatment with escitalopram (mean daily dose 18.62 mg, SD 5.15) and memantine (mean daily dose 13.62 mg, SD 6.67) was associated with improvement in Hamilton Depression Rating Scale scores over the 48-week study period. Patients demonstrated significant improvement in the primary outcome of cognitive performance (Selective Reminding Test total immediate recall; SRT-IR) over the 48-week treatment period (p = 0.0147). Significant improvement was also observed in measures of naming and verbal fluency but not in the other cognitive domains. One of the 35 patients (2.9%) converted to Alzheimer's disease over the 48-week treatment period. In the amnestic mild cognitive impairment subsample (n = 22), the conversion rate was 4.5%, a rate lower than in other reports of patients with DEP-CI.

CONCLUSIONS

In this open-label trial, combined antidepressant and memantine treatment in patients with DEP-CI was associated with improved cognition and a low rate of conversion to dementia compared with published studies in patients with DEP-CI. Although limited by the open-label study design that incorporates practice effects that can improve cognitive test performance, the findings suggest the need for a larger randomized placebo-controlled trial.

Depression and dementias among military veterans

Depression is very common throughout the course of veterans' lives, and dementia is common in late life. Previous studies suggest an association between depression and dementia in military veterans. The most likely biologic mechanisms that may link depression and dementia among military veterans include vascular disease, changes in glucocorticoid steroids and hippocampal atrophy, deposition of β-amyloid plaques, inflammatory changes, and alterations of nerve growth factors. In addition, military veterans often have depression comorbid with posttraumatic stress disorder or traumatic brain injury. Therefore, in military veterans, these hypothesized biologic pathways going from depression to dementia are more than likely influenced by trauma-related processes. Treatment strategies for depression, posttraumatic stress disorder, or traumatic brain injury could alter these pathways and as a result decrease the risk for dementia. Given the projected increase of dementia, as well as the projected increase in the older segment of the veteran population, in the future, it is critically important that we understand whether treatment for depression alone or combined with other regimens improves cognition. In this review, we summarize the principal mechanisms of this relationship and discuss treatment implications in military veterans.

Cognition as a target in major depression: new developments

Major depressive disorder (MDD) is a highly prevalent and disabling psychiatric illness often accompanied of cognitive dysfunction which may persist even when patients achieve clinical remission. Currently, cognitive deficits emerge as a potential target because they compromise the functional outcome of depressed patients. The aim of this study was to review data for several potential pharmacological treatments targeting cognition in MDD, resulting from monotherapy or adjunctive treatment. An extensive and systematic Pubmed/Medline search of the published literature until March 2014 was conducted using a variety of search term to find relevant articles. Bibliographies of retrieved papers were further examined for publications of interest. Searches were limited to articles available in English language. We describe studies using modafinil, lisdexamfetamine, ketamine, lanicemine, memantine, galantamine, donepezil, vortioxetine, intranasal oxytocin, omega-3, s-adenosyl-methionine, scopolamine and erythropoietin. From these articles, we determined that there are a number of promising new therapies, pharmacological agents or complementary medicines, but data are just emerging. Drugs and therapies targeting cognitive dysfunction in MDD should prove effective in improving specific cognitive domains and functioning, while ruling out pseudospecificity.

Pharmacological and non-pharmacological interventions to improve cognitive dysfunction and functional ability in clinical depression--a systematic review

Cognitive dysfunction is of clinical significance and exerts longstanding implication on patients׳ function. Pharmacological and non-pharmacological treatments of cognitive dysfunction are emerging. This review evaluates pharmacological and non-pharmacological treatments of cognitive impairment primarily in the domains of memory, attention, processing speed and executive function in clinical depression. A total of 35 studies were retrieved from Pubmed, PsycInfo and Scopus after applying inclusion and exclusion criteria. Results show that various classes of antidepressants exert improving effects on cognitive function across several cognitive domains. Specifically, studies suggest that SSRIs, the SSRE tianeptine, the SNRI duloxetine, vortioxetine and other antidepressants such as bupropion and moclobemide may exert certain improving effects on cognitive function in depression, such as in learning and memory and executive function. Class-specific cognitive domains or specific dose-response relationships were not identified yet. The few non-pharmacological studies conducted employing cognitive orientated treatments and cognitive remediation therapy show promising results for the improvement of cognitive impairment in depression. However, several methodological constraints of studies limit generalizability of the results and caution the interpretation. Future direction should consider the development of a neuropsychological consensus cognitive battery to support the discovery, clinical assessment, comparison of studies and registration of new agents in clinical depression.

Impact of pharmacological and psychological treatment methods of depressive and anxiety disorders on cognitive functioning

Anxiety and depressive disorders are characterized by a number of clinical symptoms like decreased mood, apathy, anhedonia and anxiety. An important element of the clinical picture is also neurocognitive impairment. The most common treatment methods for depression and anxiety are pharmacology, psychotherapy or a combination of both methods. The data from literature show that those treatment methods lead to an improvement of clinical symptoms, but they exert a possible impact on cognitive functions. However the study results referring both to the role of pharmacological treatment and psychotherapy in this domain are still inconsistent. There is an increasing number of accessible data confirming the positive effects of those clinical interventions on cognitive functioning of anxiety and depressive patients, but the interpretation is complicated because of differences in methodology as well as examined sample size and their characteristics. More studies are then needed to describe this phenomenon.

Neuropsychiatric symptoms in the prodromal stages of dementia

PURPOSE OF REVIEW

To critically discuss the neuropsychiatric symptoms in the prodromal stages of dementia in order to improve the early clinical diagnosis of cognitive and functional deterioration.

RECENT FINDINGS

Current criteria for cognitive syndrome, including Alzheimer's disease, comprise the neuropsychiatric symptoms in addition to cognitive and functional decline. Although there is growing evidence that neuropsychiatric symptoms may precede the prodromal stages of dementia, these manifestations have received less attention than traditional clinical hallmarks such as cognitive and functional deterioration. Depression, anxiety, apathy, irritability, agitation, sleep disorders, among other symptoms, have been hypothesized to represent a prodromal stage of dementia or, at least, they increase the risk for conversion from minor neurocognitive disorder to major neurocognitive disorder. Longitudinal investigations have provided increased evidence of progression to dementia in individuals with minor neurocognitive disorder when neuropsychiatric symptoms also were present.

SUMMARY

Although neuropsychiatric symptoms are strongly associated with a higher risk of cognitive and functional deterioration, frequently the clinician does not acknowledge these conditions as increasing the risk of dementia. When the clinician accurately diagnoses neuropsychiatric symptoms in the prodromal stage of dementia, he could early establish appropriate treatment and, may be, delay the beginning of clinical and functional deterioration.

The nuances of cognition and depression in older adults: the need for a comprehensive assessment

OBJECTIVES

This study aimed to examine the confluence of depression, cognitive impairment, and vascular risk factors in older individuals.

METHODS

The study uses baseline data from the National Alzheimer's Coordinating Center. Data were collected across Alzheimer's Disease Centers in the USA. The sample included 12,634 individuals (cognitive intact = 8022; amnestic mild cognitive impairment [aMCI] = 3652; nonamnestic MCI [nonaMCI] = 960). The Geriatric Depression Scale assessed depression; the Trail Making Test assessed executive function.

RESULTS

The proportion of participants with depression was higher in the aMCI (18%) and nonaMCI group (21%) as compared with that in the cognitively intact group (8%); there was no difference in rates of depression between aMCI and nonaMCI groups. The proportion of participants with executive dysfunction differed between nondepressed and depressed individuals for the cognitively intact (8% vs. 12%) and aMCI groups (28% vs. 35%), but not for the nonaMCI group (37% vs. 41%). Nine percent of the cognitively intact group had executive dysfunction compared with 31% of the aMCI group and 40% of the nonaMCI group. The proportion of participants with hypertension was greater in individuals with executive dysfunction compared with those with no executive deficits; the presence of hypertension was not associated with depression severity.

CONCLUSIONS

The confluence of vascular risk factors, episodic memory impairment, and depression and executive dysfunction highlights the need for comprehensive assessment of depressed older adults that can aid clinicians in the formulation of treatment planning and inform clinicians and researchers about long-term prognosis.

Dysthymic disorder in the elderly population

The diagnosis of dysthymic disorder was created in DSM-III and maintained in DSM-IV to describe a depressive syndrome of mild to moderate severity of at least two years' duration that did not meet criteria for major depressive disorder. The prevalence of dysthymic disorder is approximately 2% in the elderly population where subsyndromal depressions of lesser severity are more common. Dysthymic disorder was replaced in DSM-V by the diagnosis of "persistent depressive disorder" that includes chronic major depression and dysthymic disorder. In older adults, epidemiological and clinical evidence supports the use of the term "dysthymic disorder." In contrast to young adults with dysthymic disorder, older adults with dysthymic disorder commonly present with late age of onset, without major depression and other psychiatric disorders, and with a low rate of family history of mood disorders. They often have stressors such as loss of social support and bereavement, and some have cerebrovascular or neurodegenerative pathology. A minority has chronic depression dating from youth with psychiatric comorbidity similar to young adults with dysthymic disorder. In older adults, both dysthymic disorder and subsyndromal depression increase disability and lead to poor medical outcomes. Elderly patients with dysthymic disorder are seen mainly in primary care where identification and treatment are often inadequate. Treatment with antidepressant medication shows marginal superiority over placebo in controlled trials, and problem-solving therapy shows similar efficacy. Combined treatment and collaborative care models show slightly better results, but cost effectiveness is a concern. Further work is needed to clarify optimal approaches to the treatment of dysthymic disorder in elderly patients.

Donepezil treatment of older adults with cognitive impairment and depression (DOTCODE study): clinical rationale and design

Treatment strategies for patients with depression and cognitive impairment (DEP-CI), who are at high risk to develop a clinical diagnosis of dementia, are not established. This issue is addressed in the donepezil treatment of cognitive impairment and depression (DOTCODE) pilot clinical trial. The DOTCODE study is the first long-term treatment trial that assesses differences in conversion to dementia and cognitive change in DEP-CI patients using a study design of open antidepressant medication plus add-on randomized, double-blind, placebo-controlled treatment with the acetylcholinesterase inhibitor donepezil. In Phase 1, DEP-CI patients receive optimized antidepressant treatment for 16 weeks. In Phase 2, antidepressant treatment is continued with the addition of randomized, double-blind treatment with donepezil or placebo. The total study duration for each patient is 78 weeks (18 months). Eighty DEP-CI outpatients (age 55 to 95 years) are recruited: 40 at New York State Psychiatric Institute/Columbia University and 40 at Duke University Medical Center. The primary outcome is conversion to a clinical diagnosis of dementia. The secondary outcomes are cognitive change scores in Selective Reminding Test (SRT) total recall and the modified Alzheimer's Disease Assessment Scale (ADAS-cog). Other key assessments include the 24-item Hamilton Depression Rating Scale and antidepressant response; Clinical Global Impression (CGI) for depression, cognition, and global status; neuropsychological test battery for diagnosis; informant report of functional abilities (Pfeffer FAQ); and Treatment Emergent Symptom Scale (TESS) for somatic side effects. Apolipoprotein E ε4 status, odor identification deficits, and MRI entorhinal/hippocampal cortex atrophy at baseline are evaluated as neurobiological moderators of donepezil treatment effects.

Treatment for mild cognitive impairment: systematic review

BACKGROUND

More people are presenting with mild cognitive impairment (MCI), frequently a precursor to dementia, but we do not know how to reduce deterioration.

AIMS

To systematically review randomised controlled trials (RCTs) evaluating the effects of any intervention for MCI on cognitive, neuropsychiatric, functional, global outcomes, life quality or incident dementia.

METHOD

We reviewed 41 studies fitting predetermined criteria, assessed validity using a checklist, calculated standardised outcomes and prioritised primary outcome findings in placebo-controlled studies.

RESULTS

The strongest evidence was that cholinesterase inhibitors did not reduce incident dementia. Cognition improved in single trials of: a heterogeneous psychological group intervention over 6 months; piribedil, a dopamine agonist over 3 months; and donepezil over 48 weeks. Nicotine improved attention over 6 months. There was equivocal evidence that Huannao Yicong improved cognition and social functioning.

CONCLUSIONS

There was no replicated evidence that any intervention was effective. Cholinesterase inhibitors and rofecoxib are ineffective in preventing dementia. Further good-quality RCTs are needed and preliminary evidence suggests these should include trials of psychological group interventions and piribedil.

Depressive Symptoms in Clinical and Incipient Alzheimer's Disease

The updated diagnostic criteria for Alzheimer's disease (AD) distinguish three stages: dementia, symptomatic pre-dementia [i.e. mild cognitive impairment (MCI)], and asymptomatic pre-dementia. Although AD is primarily associated with cognitive deficits, co-morbid depressive symptoms frequently occur at each stage. Depression in AD dementia is qualitatively different from depression in cognitively intact and/or younger populations, and may be less responsive to established interventions. In MCI, depressive symptoms are associated with higher rates of progression to dementia, and may identify a subset of individuals that are more responsive to acetylcholinesterase inhibitor treatment. Clinical and subsyndromal depressive symptoms in cognitively normal elderly represent a risk factor and/or prodrome for dementia due to AD, but sustained antidepressant therapy may be able to modulate this risk.

Cholinesterase inhibitor adjunctive therapy for cognitive impairment and depressive symptoms in older adults with depression

OBJECTIVE

To review the primary literature regarding the use of cholinesterase inhibitors (ChEIs) as adjunctive therapy for cognitive enhancement and improvement of depressive symptoms for older adults with depression.

DATA SOURCES

A literature search of MEDLINE (1950-September 2011) was conducted, using the search term depression in combination with cholinesterase inhibitor, donepezil, galantamine, or rivastigmine. A search of reference citations was conducted to identify additional references.

STUDY SELECTION AND DATA EXTRACTION

English-language clinical trials were evaluated. Studies that included subjects with Alzheimer's disease, dementia, Parkinson disease, bipolar disorder, or schizophrenia were excluded. Four clinical studies met our criteria.

DATA SYNTHESIS

We identified 4 randomized, double-blind, placebo-controlled trials that ranged in sample size from 20 to 130. Galantamine 16 mg daily was evaluated in 2 trials lasting 8 and 24 weeks. Neither study found a statistically significant difference in measures of cognition or Hamilton Rating Scale for Depression scores. Donepezil augmentation was evaluated in a 1-year and a 2-year trial. Donepezil was found to improve global cognition at 1 year, but the benefit did not persist at year 2. Subjects with mild cognitive impairment at baseline who received donepezil experienced higher depression recurrence than did those who took placebo (p = 0.03); this effect was not observed in cognitively intact subjects (p = 0.39).

CONCLUSIONS

There is no clear benefit for ChEI therapy as an adjunct to antidepressant therapy for depressed older adults.

Depression and risk of developing dementia

Depression is highly common throughout the life course and dementia is common in late life. Depression has been linked with dementia, and growing evidence implies that the timing of depression may be important in defining the nature of this association. In particular, earlier-life depression (or depressive symptoms) has consistently been associated with a more than twofold increase in dementia risk. By contrast, studies of late-life depression and dementia risk have been conflicting; most support an association, yet the nature of this association (for example, if depression is a prodrome or consequence of, or risk factor for dementia) remains unclear. The likely biological mechanisms linking depression to dementia include vascular disease, alterations in glucocorticoid steroid levels and hippocampal atrophy, increased deposition of amyloid-β plaques, inflammatory changes, and deficits of nerve growth factors. Treatment strategies for depression could interfere with these pathways and alter the risk of dementia. Given the projected increase in dementia incidence in the coming decades, understanding whether treatment for depression alone, or combined with other regimens, improves cognition is of critical importance. In this Review, we summarize and analyze current evidence linking late-life and earlier-life depression and dementia, and discuss the primary underlying mechanisms and implications for treatment.

Maintenance treatment of depression in old age: a randomized, double-blind, placebo-controlled evaluation of the efficacy and safety of donepezil combined with antidepressant pharmacotherapy

CONTEXT

Cognitive impairment in late-life depression is a core feature of the illness.

OBJECTIVE

To test whether donepezil hydrochloride and antidepressant therapy is superior to placebo and antidepressant therapy in improving cognitive performance and instrumental activities of daily living and in reducing recurrences of depression over 2 years of maintenance treatment.

DESIGN

Randomized, double-blind, placebo-controlled maintenance trial.

SETTING

University clinic.

PARTICIPANTS

One hundred thirty older adults aged 65 years and older with recently remitted major depression.

INTERVENTIONS

Random assignment to maintenance antidepressant pharmacotherapy and donepezil or to maintenance antidepressant pharmacotherapy and placebo.

MAIN OUTCOME MEASURES

Global neuropsychological performance, cognitive instrumental activities of daily living, and recurrent depression.

RESULTS

Donepezil and antidepressant therapy temporarily improved global cognition (treatment × time interaction, F₂,₂₁₆ = 3.78; P = .03), but effect sizes were small (Cohen d = 0.27, group difference at 1 year). A marginal benefit to cognitive instrumental activities of daily living was also observed (treatment × time interaction, F₂,₁₃₇ = 2.94; P = .06). The donepezil group was more likely than the placebo group to experience recurrent major depression (35% [95% confidence interval {CI}, 24%-46%] vs 19% [95% CI, 9%-29%], respectively; log-rank χ² = 3.97; P = .05; hazard ratio = 2.09 [95% CI, 1.00-4.41]). Post hoc subgroup analyses showed that of 57 participants with mild cognitive impairment, 3 of 30 participants (10% [95% CI, 0%-21%]) receiving donepezil and 9 of 27 participants (33% [95% CI, 16%-51%]) receiving placebo had a conversion to dementia over 2 years (Fisher exact test, P = .05). The mild cognitive impairment subgroup had recurrence rates of major depression of 44% with donepezil vs 12% with placebo (likelihood ratio = 4.91; P = .03). The subgroup with normal cognition (n = 73) showed no benefit with donepezil and no increase in recurrence of major depression.

CONCLUSIONS

Whether a cholinesterase inhibitor should be used as augmentation in the maintenance treatment of late-life depression depends on a careful weighing of risks and benefits in those with mild cognitive impairment. In cognitively intact patients, donepezil appears to have no clear benefit for preventing progression to mild cognitive impairment or dementia or for preventing recurrence of depression.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00177671.

A new strategy for antidepressant prescription

From our research and literature search we propose an understanding of the mechanism of action of antidepressants treatments (ADTs) that should lead to increase efficacy and tolerance. We understand that ADTs promote synaptic plasticity and neurogenesis. This promotion is linked with stimulation of dopaminergic receptors. Previous evidence shows that all ADTs (chemical, electroconvulsive therapy, repetitive transcranial magnetic stimulation, sleep deprivation) increase at least one monoamine neurotransmitter serotonin (5-HT), noradrenaline (NA) or dopamine (DA); this article focuses on DA release or turn-over in the frontal cortex. DA increased dopaminergic activation promotes synaptic plasticity with an inverted U shape dose–response curve. Specific interaction between DA and glutamate is mediated by D1 receptor subtypes and Glutamate (NMDA) receptors with neurotrophic factors likely to play a modulatory role. With the understanding that all ADTs have a common, final, DA-ergic stimulation that promotes synaptic plasticity we can predict that (1) AD efficiency is related to the compound strength for inducing DA-ergic stimulation. (2) ADT efficiency presents a therapeutic window that coincides with the inverted U shape DA response curve. (3) ADT delay of action is related to a “synaptogenesis and neurogenesis delay of action.” (4) The minimum efficient dose can be found by starting at a low dosage and increasing up to the patient response. (5) An increased tolerance requires a concomitant prescription of a few ADTs, with different or opposite adverse effects, at a very low dose. (6) ADTs could improve all diseases with cognitive impairments and synaptic depression by increasing synaptic plasticity and neurogenesis.

Defining and measuring functional recovery from depression

Depression is associated with significant functional impairment and reduced quality of life. Disruptions occur both globally as well as in specific functional areas such as work, interpersonal relationships and cognitive function. From both a clinical and research perspective, much focus has been given to the resolution of symptoms associated with depression, while relatively little attention has been given to functional improvements. Definitions of remission in depression are most frequently based on achieving a cut-off score on clinical rating scales of depressive symptoms. Research in this area has sparsely included psychosocial function or health-related quality of life as a primary outcome measure in clinical trials. However, the need to fully understand the impact of depression and its treatments on functioning is great, given the existing evidence of the profound effect that depression has on function. Even mild depressive symptoms and subsyndromal depression result in functional impairment and reduced quality of life, and untreated residual depressive symptomatology can result in an increased likelihood for relapse of the fully symptomatic disorder (i.e. major depressive disorder). Therefore, clinicians and researchers alike need to broaden the focus of treatment to encompass not only the specific symptoms of depression, but the functional consequences as well. Many tools have been developed to assess function and quality of life, both globally as well as within specific domains. In addition, the effect of residual symptoms associated with functional impairment (i.e. insomnia, fatigue, pain [somatic] symptoms and cognition) in depression, even independently of depressive symptoms, warrants evaluation and monitoring. Recommendations for evaluating functional outcomes include: (i) adequately assessing functional impairment; (ii) identifying and/or developing treatment plans that will target symptoms associated with functional impairments; and (iii) monitoring functional impairments and associated symptoms throughout the course of treatment. The development of treatments that specifically target improvements in functional impairments is needed, and may require the use of novel treatment strategies.

[Cholinesterase inhibitors and depression in the elderly]

BACKGROUND

Depression in the elderly is characterized by an atypical expression with delusion, major anxiety, behaviour disorders, somatic complains or cognitive impairment. These clinical aspects are suspected to be at the origin of the poor response to antidepressants observed in these cases. It is currently indicated to add sedative medicines to antidepressants, when a major anxiety is associated with depression, or an antipsychotic in the delusional forms of the depression. However, it is not consensually established that cholinesterase inhibitors can be helpful in depression with cognitive impairment. Cholinesterase inhibitors are efficient among patients with Alzheimer disease. They improve cognitive performances and slow down the degenerative process during the first years of treatment. Today, new findings on neurobiological mechanisms of depression involve a located degenerative process, with some similar anomalies in the brain in both depression and pre-Alzheimer states. New therapeutic trials have shown that cholinesterase inhibitors can be also efficient on depressed symptoms among patients with Alzheimer disease. These evidences support the hypothesis that the association of cholinesterase inhibitors to antidepressants can bring more benefits to depressed elderly patients.

AIM

Through a review of the literature and a case report, we tried to specify whether cholinesterase inhibitors can be useful in the treatment of depression among the elderly.

CASE REPORT

We report the case of a 68-year-old man who had presented, four years ago, a second episode of major depression with a cognitive impairment. Treated with an antidepressant (venlafaxine), the improvement was poor with major anxiety, slow thoughts, and an evidence of a persistent cognitive impairment. Despite normal cerebral scanning images, we decided to add a cholinesterase inhibitor (donepezil) to the same antidepressant. With this association, we rapidly obtained a total remission from depression with restitution of cognitive performances. This state is still maintained until today (four years after the last depressive episode) with no new mood relapses. Recent cerebral scanning images did not show any degenerative process.

CONCLUSION

The association of cholinesterase inhibitors and an antidepressant seems a good alternative, when the response to antidepressant is partial in depression with cognitive impairment in the elderly. However, further therapeutic trials are still needed, to prove the usefulness of cholinesterase inhibitors among depressed elderly patients.

Efficacy of SSRIs on cognition of Alzheimer's disease patients treated with cholinesterase inhibitors

BACKGROUND

This study examines the joint effect on cognition of selective serotonin re-uptake inhibitors (SSRIs) and cholinesterase inhibitors (AChEIs) in depressed patients affected by Alzheimer's disease (AD) living at home.

METHODS

The study was conducted in two different outpatient neurological clinics. 338 patients with probable AD were treated with ChEis (donepezil, rivastigmine and galantamine) as per the clinician's judgment and were observed for nine months. At study entry, participants underwent a multidimensional assessment evaluating cognitive, functional and psychobehavioral domains. All patients were evaluated at baseline, after one (T1), three (T2) and nine months (T3). Patients were grouped in three different categories (patients not depressed and not treated with SSRIs, patients depressed and treated with SSRIs, and patients depressed but not treated with SSRIs).

RESULTS

At baseline 182 were diagnosed as not depressed and not treated with SSRIs, 66 as depressed and treated with SSRIs, and 90 as depressed but not treated with SSRIs. The mean change in MMSE score from baseline to nine months showed that depressed patients not treated worsened in comparison with those not depressed and not treated with SSRIs (mean change -0.8 +/- 2.3 vs 0.04 +/- 2.9; p = 0.02) and patients depressed and treated with SSRI (mean change -0.8 +/- 2.3 vs 0.1 +/- 2.5; p = 0.03).

CONCLUSIONS

In AD patients treated with AChEIs, SSRIs may exert some degree of protection against the negative effects of depression on cognition.

Strategies to enhance the therapeutic efficacy of antidepressants: targeting residual symptoms

Major depressive disorder (MDD) is an illness of great morbidity that affects many people across the world. The current goal for treatment of MDD is to achieve remission (i.e., no depressive symptoms). However, despite scientific advances in the treatment for MDD, antidepressants as first-line agents yield only modest remission rates. In fact, a recent study indicated that only one out of three subjects who received a standard, first-line antidepressant attained remission. Not achieving remission from depressive symptoms increases the risk of a more chronic and debilitating course of illness with frequent recurrences. Although a number of reasons contribute to these modest outcomes, the presence of residual symptoms is a major problem. Residual symptoms are defined as symptoms that linger despite an adequate dose and duration of an antidepressant medication. This article reviews the prevalence and clinical impact of common residual symptoms and discusses the utility of aggressively addressing residual symptoms to enhance the efficacy of antidepressant medications.

Neurocognitive correlates of response to treatment in late-life depression

Depression is often associated with neurocognitive deficits in older adults, particularly in the domains of information processing speed, episodic memory, and executive functions. Greater neurocognitive dysfunction while depressed is associated with a less effective treatment response; however, questions remain about the specific variables that characterize patients showing low treatment response and persistent cognitive deficiencies.

OBJECTIVES

The authors examined neurocognitive variables that differentiated patients who showed robust versus weak responses to antidepressant therapy.

PARTICIPANTS

The baseline sample included 110 women and 67 men, with a mean age of 69.1 years (SD = 6.9) and mean education of 14 years (SD = 3.3).

DESIGN

Patients enrolled in a treatment study completed both a structured diagnostic assessment for depression and neuropsychological testing at study entry and 1-year follow-up.

MEASUREMENTS

Clinicians rated patient depression using the Montgomery-Asberg Depression Rating Scale. Neuropsychological assessments consisted of prose recall and percent retention (Wechsler Memory Scale -III Logical Memory), word-list recall, attention and visuomotor processing speed (Trail Making A, Symbol Digit Modalities Test), and mental flexibility (Trail Making B).

INTERVENTIONS

Patients underwent treatment for depression following the guidelines of the Duke Somatic Treatment Algorithm for Geriatric Depression approach.

RESULTS

Individuals who demonstrated the greatest improvement in mood symptoms at follow-up exhibited better prose recall and faster processing speed at baseline than individuals who demonstrated weaker treatment responses. These differences remained after controlling for depression severity at both time-points.

CONCLUSION

The current results suggest that better pretreatment cognitive function, particularly in verbal memory, is associated with a greater treatment response in late-life depression.

Donepezil for mild cognitive impairment

BACKGROUND

Problems with memory which do not meet the diagnostic criteria for dementia, usually called mild cognitive impairment (MCI), can be the first sign of an impending dementia, particularly Alzheimer's disease (AD). There is no consensus on a definition or diagnostic criteria for MCI, and MCI remains a vague term and those so described are a heterogeneous population, consisting of people who may rapidly progress to dementia but also of people with stable cognitive deficits and some who may actually improve. Treatment in the very earliest stages of AD may delay progression to AD. Donepezil (Aricept, E2020), a cholinesterase inhibitor, has been shown to benefit all severities of AD including mild and it would be reasonable to investigate its efficacy for those with MCI.

OBJECTIVES

To assess the effects of donepezil in people with mild cognitive impairment but no diagnosis of dementia.

SEARCH STRATEGY

The trials were identified from a search of the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group on 6 January 2006. This register contains records from major health care databases like CENTRAL, MEDLINE, EMBASE, CINAHL and PsycINFO and many ongoing trial databases and is updated regularly.

SELECTION CRITERIA

All double blind, randomized trials in which treatment with donepezil was compared with placebo for patients with mild cognitive impairment.

DATA COLLECTION AND ANALYSIS

Data were extracted from the published reports of the included studies, pooled where appropriate and the treatment effects or the risks and benefits estimated.

MAIN RESULTS

The two included studies, with a total of 782 patients, all with a MMSE greater than 23 points, identified similar patients for inclusion, but were quite different with respect to design and objective. Pooling results in a meta-analysis was not possible. In the first study the 13-item ADAS-Cog showed benefit associated with 10 mg/day donepezil compared with placebo at 24 weeks (MD 1.90, 95% CI 0.51 to 3.29, p=0.007), but four other measures of cognitive function did not. The analysis of withdrawals before the end of treatment at 24 weeks, withdrawals due to an adverse event, and numbers experiencing an adverse event, showed a significant difference between the donepezil group and the placebo group in favour of placebo, (43/133 donepezil 23/137 placebo, OR 2.37, 95% CI 1.33 to 4.22, p=0.003), (29/133 donepezil 10/137 placebo, OR 3.54, 95% CI 1.65 to 7.60, p=0.001), (116/133 donepezil, 100/137 placebo, OR 2.52 95% CI 1.34 to 4.76, p=0.004). Various adverse effects were recorded, and several types of event, diarrhoea, nausea, vomiting, leg cramps and abnormal dreams, were reported more frequently in the donepezil group compared with the placebo. In the second study there was a significant difference between the number of patients diagnosed with AD or another dementia between the donepezil group and the placebo group in favour of donepezil after one year of treatment (16/253 donepezil 38/259 placebo) (OR 0.39, 95% CI 0.21 to 0.72, p=0.003), but no difference after 3 years of treatment (63/253 donepezil 73/259 placebo) (OR 0.84, 95% CI 0.57 to 1.25, p=0.4).

AUTHORS' CONCLUSIONS

There are two included studies. One study demonstrated a modest treatment effect in cognitive function as assessed by ADAS-Cog13 but not for other outcomes assessing different domains of cognitive function. Donepezil was associated with significantly more adverse effects compared with placebo, mostly gastrointestinal. From the second study, there is no evidence that donepezil delays the onset of AD. There is no evidence to support the use of donepezil for patients with MCI. The putative benefits are minor, short lived and associated with significant side effects.