Association between brain amyloid accumulation and neuropsychological characteristics in elders with depression and mild cognitive impairment

Dementia risk in middle-aged patients with schizophrenia, bipolar disorder, and major depressive disorder: a cohort study of 84,824 subjects

All severe mental disorders, namely schizophrenia, bipolar disorder, and major depression, are associated with dementia. However, a head-to-head comparison study of severe mental disorders and dementia risk is lacking. This study was a retrospective analysis from Taiwan National Health Insurance Database. In the current study, we included 14,137, 14,138, and 14,137 patients aged 45-69 years diagnosed with schizophrenia, bipolar disorder, and major depressive disorder, respectively, between 2001 and 2009 and 42,412 matched controls. Four groups were age-matched based by age of identification. Any dementia, including Alzheimer disease and vascular dementia, was diagnosed from the identification date to the end of 2011. Alzheimer disease was more likely in patients with bipolar disorder (hazard ratio [HR]: 10.37, 95% confidence interval [CI]: 6.93-15.52) and major depression (HR: 8.92, 95% CI: 5.93-13.41) than in those with schizophrenia (HR: 4.50, 95% CI: 2.84-7.13) and in controls. The likelihood of developing vascular dementia during the follow-up period was greater in patients with schizophrenia (HR: 4.55, 95% CI: 3.14-6.59) and bipolar disorder (HR: 4.45, 95% CI: 3.13-6.31) than in those with major depression (HR: 3.18, 95% CI: 2.21-4.58) and in controls. However, the overlapped CIs indicated the non-significant between-category differences. There was an increased risk of Alzheimer disease and vascular dementia in all groups compared with controls. For Alzheimer disease risk was greater bipolar and depression compared with schizophrenia while for vascular dementia risk was greater for bipolar and schizophrenia compared with depression. Our findings may encourage clinicians to closely monitor the trajectory of cognitive function in middle-aged and elderly patients with schizophrenia, bipolar disorder, and major depressive disorder.

Brain amyloid accumulation possibly exacerbates concurrent mild cognitive impairment with subthreshold depression in older adults: A 1-year follow-up study

BACKGROUND

This study aimed to investigate the 1-year changes in neuropsychological test results in older adults with concomitant late-life depression (LLD) and mild cognitive impairment (MCI) according to the presence or absence of brain amyloidopathy.

METHODS

All subjects underwent ¹⁸F-florbetaben-positron emission tomography and a standardized neuropsychological battery. The subjects were divided based on brain amyloidopathy and severity of depressive symptoms into the following groups: LLD-MCI-A(+), subthreshold depression (STD)-MCI-A(+), major depressive disorder (MDD)-MCI-A(+), LLD-MCI-A(-), STD-MCI-A(-), and MDD-MCI-A(-). After one year, follow-up neurocognitive tests were conducted. Fifty-nine participants completed both the baseline and 1-year follow-up neurocognitive tests.

RESULTS

In the LLD-MCI-A(+) group, the word list recall and word list recognition scores decreased during the follow-up period. The STD-MCI-A(+) group also showed a significant decrease in word list recall score and the score/Z-score of word list recognition. On the other hand, the word list recall Z-score improved at the 1-year follow-up in the LLD-MCI-A(-) group. In particular, the MDD-MCI-A(-) group showed significant increases in word list memory score/Z-score and word list recall Z-score during the follow-up period.

LIMITATIONS

Considering that AD progresses slowly, a longer follow-up period may be required.

CONCLUSIONS

Our findings showed differences in the extent of change of neuropsychological test results depending on the severity of depressive symptoms and presence or absence of brain amyloidopathy. Our results suggest that clinicians might explore the underlying neuropathology when assessing older adults with concomitant depression and cognitive impairment, even if the symptoms of depression are not severe.

[Depression and its relationship with mild cognitive impairment and Alzheimer disease: A review study]

The objective of the present study was to determine whether depression precedes Mild cognitive impairment (MCI) as a risk factor or as a predictor in Alzheimer's disease (AD). A systematic review of observational studies (cross-sectional and cohort or follow-up) was carried out using the PRISMA search algorithm, for clinical markers in MCI and AD, in the Science Direct, Springer, Scopus and Proquest databases. The study eligibility criteria included inclusion criteria: of types of documents, articles of primary studies, type of source scientific journals, published in the English language, from January 2010 to April 2020, in patients with MCI and AD and in the group of age included in people with a minimum age range of 45years. Exclusion criteria were: publications older than 10years because the aim of the article was to explore recent studies, secondary research studies, type of report document, languages other than English. 3385 articles were identified, of which 30 articles were finally selected. It was found that there is an association between depression and AD, but properly as a risk factor but not, as a predictor or clinical marker of the development of AD. The degree of association is greater when they present depressive symptoms and simultaneously report subjective memory complaints or the presence of MCI.

Different Sides of Depression in the Elderly: An In-depth View on the Role of Aβ Peptides

BACKGROUND

Late-onset depression (LOD) is the most common neuropsychiatric disorder associated with Alzheimer's disease (AD), often associated with structural and functional brain changes, neuropsychological impairments and negative family history for affective disorders. LOD could be a risk factor or a prodromal phase of AD; this has led to the investigation of the link between depression and amyloid-β (Aβ) peptides by measuring Aβ levels in plasma, cerebrospinal fluid (CSF) and brains of elderly depressed subjects.

OBJECTIVE

Clarify the complex relationship between depression, Aβ peptides and AD.

METHOD

We evaluated all articles published up to 2019 in PubMed in which Aβ was measured in serum (or plasma), CSF or brain in elderly with Major Depressive Disorder or depressive symptoms evaluated with standard scales.

RESULTS

Low plasma Aβ42 levels are strongly associated with depression severity. Plasma Aβ40 levels are higher in younger depressed, drug-resistant and those with more severe symptoms. CSF Aβ42 levels are lower in depressed than controls. PET-detected global and region-specific increases in Aβ deposition are sometimes associated with LOD, cognitive impairment, anxiety but not with Cardiovascular Diseases (CVDs)/CVD risk factors. Elderly depressed with CVDs/CVD risk factors have more frequently high plasma Aβ40 levels and drug-resistance; those without these co-morbidities have low plasma Aβ42 levels and a greater cognitive impairment.

CONCLUSION

Two specific Aβ profiles emerge in elderly depressed. One is associated with Aβ42 reductions in plasma and CSF, possibly reflecting increased brain amyloid deposition and prodromal AD. The other one is characterized by high plasma Aβ40 levels, cerebrovascular disease and clinically associated with increased AD risk.

The effects of cerebral amyloidopathy on regional glucose metabolism in older adults with depression and mild cognitive impairment while performing memory tasks

Co-occurring depression and mild cognitive impairment (MCI) in older adults are important because they have a high risk of conversion to dementia. In the present study, task-related F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) was used to analyse older adults with concomitant depression and MCI. We recruited 20 older adults with simultaneous depression and MCI and 10 older adults with normal cognition (NC). The Verbal Paired Associates test and digit span test were used for the task-related FDG-PET. The 20 older adults with depression and MCI were classified into two groups based on the F-18 florbetaben PET results: depressed MCI patients with (LLD-MCI-A[+]; n = 11) and without amyloid accumulation (LLD-MCI-A[-]; n = 9). Reduced regional cerebral glucose metabolism (rCMglc) in the left superior frontal region was observed in the LLD-MCI-A(-) group compared with the NC group. Analyses of the NC and LLD-MCI-A(+) groups showed significantly decreased rCMglc in the right inferior parietal and left middle frontal regions in the LLD-MCI-A(+) group. rCMglc in the left precuneus was lower in the LLD-MCI-A(+) group than in the LLD-MCI-A(-) group. Significant correlations between the rCMglc in the right inferior parietal/left precuneus regions and memory task scores were observed based on correlation analyses of NC and LLD-MCI-A(+) groups. The findings in the present study indicate the presence of amyloid accumulation influences glucose metabolism in depressed elderly subjects with MCI while performing cognitive tasks. Task-related FDG-PET examinations may help differentiate MCI associated with depression from comorbid depression in patients with prodromal Alzheimer's disease.

Molecular imaging of beta-amyloid deposition in late-life depression

Late-life depression (LLD) is associated with an increased risk of all-cause dementia and may involve Alzheimer's disease pathology. Twenty-one LLD patients who met the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, criteria for a current major depressive episode and 21 healthy controls underwent clinical and neuropsychological assessments, magnetic resonance imaging to measure gray matter volumes, and high-resolution positron emission tomography to measure beta-amyloid (Aβ) deposition. Clinical and neuropsychological assessments were repeated after 10-12 weeks of Citalopram or Sertraline treatment (LLD patients only). LLD patients did not differ from healthy controls in baseline neuropsychological function, although patients improved in both depressive symptoms and visual-spatial memory during treatment. Greater Aβ in the left parietal cortex was observed in LLD patients compared with controls. Greater Aβ was correlated with greater depressive symptoms and poorer visual-spatial memory, but not with improvement with treatment. The study of LLD patients with prospective measurements of mood and cognitive responses to antidepressant treatment is an opportunity to understand early neurobiological mechanisms underlying the association between depression and subsequent cognitive decline.

Influence of Pathogenic and Metabolic Genes on the Pharmacogenetics of Mood Disorders in Alzheimer's Disease

Background: Mood disorders represent a risk factor for dementia and are present in over 60% of cases with Alzheimer’s disease (AD). More than 80% variability in drug pharmacokinetics and pharmacodynamics is associated with pharmacogenetics. Methods: Anxiety and depression symptoms were assessed in 1006 patients with dementia (591 females, 415 males) and the influence of pathogenic (APOE) and metabolic (CYP2D6, CYP2C19, and CYP2C9) gene variants on the therapeutic outcome were analyzed after treatment with a multifactorial regime in a natural setting. Results and Conclusions: (i) Biochemical, hematological, and metabolic differences may contribute to changes in drug efficacy and safety; (ii) anxiety and depression are more frequent and severe in females than males; (iii) both females and males respond similarly to treatment, showing significant improvements in anxiety and depression; (iv) APOE-3 carriers are the best responders and APOE-4 carriers tend to be the worst responders to conventional treatments; and (v) among CYP2D6, CYP2C19, and CYP2C9 genophenotypes, normal metabolizers (NMs) and intermediate metabolizers (IMs) are significantly better responders than poor metabolizers (PMs) and ultra-rapid metabolizers (UMs) to therapeutic interventions that modify anxiety and depression phenotypes in dementia. APOE-4 carriers and CYP-related PMs and UMs deserve special attention for their vulnerability and poor response to current treatments.

Brain network analysis reveals that amyloidopathy affects comorbid cognitive dysfunction in older adults with depression

Late-life depression (LLD) may increase the risk of Alzheimer's dementia (AD). While amyloidopathy accelerates AD progression, its role in such patients has not yet been elucidated. We hypothesized that cerebral amyloidopathy distinctly affects the alteration of brain network topology and may be associated with distinct cognitive symptoms. We recruited 26 and 27 depressed mild cognitive impairment (MCI) patients with (LLD-MCI-A(+)) and without amyloid accumulation (LLD-MCI-A(-)), respectively, and 21 normal controls. We extracted structural brain networks using their diffusion-weighted images. We aimed to compare the distinct network deterioration in LLD-MCI with and without amyloid accumulation and the relationship with their distinct cognitive decline. Thus, we performed a group comparison of the network topological measures and investigated any correlations with neurocognitive testing scores. Topological features of brain networks were different according to the presence of amyloid accumulation. Disrupted network connectivity was highly associated with impaired recall and recognition in LLD-MCI-A(+) patients. Inattention and dysexecutive function were more influenced by the altered networks involved in fronto-limbic circuitry dysfunction in LLD-MCI-A(-) patients. Our results show that alterations in brain network topology may reflect different cognitive dysfunction depending on amyloid accumulation in depressed older adults with MCI.

Cerebral amyloid accumulation is associated with distinct structural and functional alterations in the brain of depressed elders with mild cognitive impairment

BACKGROUND

Elderly patients with late-life depression (LLD) often report mild cognitive impairment (MCI), so Alzheimer's disease (AD) is hard to identify in these patients. We aimed to identify the structural and functional differences between prodromal AD and LLD-related MCI.

METHODS

We performed voxel-based morphometry and functional connectivity (FC) analyses in elderly patients with both LLD and MCI to compare alterations between those with cerebral amyloidopathy and those without. We subdivided patients into subthreshold depression (STD) and major depressive disorder (MDD) groups. Using florbetaben positron emission tomography (PET), we compared volume and connectivity between healthy controls and four STD and MDD groups with or without amyloid deposition(A): STD-MCI-A(+), MDD-MCI-A(+), STD-MCI-A(-), and MDD-MCI-A(-).

RESULTS

Subjects with MDD or amyloid deposition showed greater volume reduction in the left middle temporal gyrus. MDD groups had lower FC than STD groups in the frontal, cortical, and limbic areas. The STD-MCI-A(+) group showed greater FC reduction than the MDD-MCI-A(-) and STD-MCI-A(-) groups, particularly in the hippocampus, parahippocampus, and frontal and temporal cortices. The functional differences associated with amyloid plaques were more evident in the STD group than in the MDD group.

LIMITATIONS

Limitations include disproportional sex ratios, inability to determine the longitudinal effects of amyloidopathy in large populations.

CONCLUSIONS

Regional gray matter loss and alterations in brain networks may reflect impairments caused by amyloid deposition and depression. Such changes may facilitate the detection of prodromal AD in elderly patients with both depression and cognitive dysfunction, allowing earlier intervention and more appropriate treatment.

Pharmacogenomics of Cognitive Dysfunction and Neuropsychiatric Disorders in Dementia

Symptomatic interventions for patients with dementia involve anti-dementia drugs to improve cognition, psychotropic drugs for the treatment of behavioral disorders (BDs), and different categories of drugs for concomitant disorders. Demented patients may take >6-10 drugs/day with the consequent risk for drug-drug interactions and adverse drug reactions (ADRs >80%) which accelerate cognitive decline. The pharmacoepigenetic machinery is integrated by pathogenic, mechanistic, metabolic, transporter, and pleiotropic genes redundantly and promiscuously regulated by epigenetic mechanisms. CYP2D6, CYP2C9, CYP2C19, and CYP3A4/5 geno-phenotypes are involved in the metabolism of over 90% of drugs currently used in patients with dementia, and only 20% of the population is an extensive metabolizer for this tetragenic cluster. ADRs associated with anti-dementia drugs, antipsychotics, antidepressants, anxiolytics, hypnotics, sedatives, and antiepileptic drugs can be minimized by means of pharmacogenetic screening prior to treatment. These drugs are substrates, inhibitors, or inducers of 58, 37, and 42 enzyme/protein gene products, respectively, and are transported by 40 different protein transporters. APOE is the reference gene in most pharmacogenetic studies. APOE-3 carriers are the best responders and APOE-4 carriers are the worst responders; likewise, CYP2D6-normal metabolizers are the best responders and CYP2D6-poor metabolizers are the worst responders. The incorporation of pharmacogenomic strategies for a personalized treatment in dementia is an effective option to optimize limited therapeutic resources and to reduce unwanted side-effects.