Subtypes of depression among patients with Alzheimer's disease and other dementias

Relationship Between Depression and Neurodegeneration: Risk Factor, Prodrome, Consequence, or Something Else? A Scoping Review

Background: The link between depression and neurodegeneration is complex and unclear. It is debated whether depression is a risk factor, a prodrome, a consequence, or unrelated. Objectives: This review examines these possibilities to clarify their connection, focusing primarily on Alzheimer's disease, vascular dementia, Parkinson's disease, and other highly comorbid neurodegenerative diseases. Methods: Eligibility criteria: The studies included in this review focused on neurodegenerative diseases with high comorbidity with depression, published in peer-reviewed English-language journals, providing empirical evidence on the link between the two conditions or theoretical frameworks that point to other studies. Non-human studies and those irrelevant to this connection were excluded. Source of evidence: AI-supported tools identified relevant articles. Results: Most studies suggest depression may contribute to neurodegeneration, but clinical, neuroimaging, and longitudinal evidence also support its role as a prodrome or consequence, indicating a bidirectional relationship. Conclusions: Despite extensive research, the connection remains unclear, highlighting the need for further investigation into underlying mechanisms and interdependencies, focusing on longitudinal studies by examining causality.

Plasma neurofilament light chain in association to late-life depression in the general population

AIM

Investigating what is underlying late-life depression is becoming increasingly important with the rapidly growing elderly population. Yet, the associations between plasma biomarkers of neuroaxonal damage and late-life depression remain largely unclear. Therefore, we determined cross-sectional and longitudinal associations of neurofilament light chain (NfL) with depression in middle-aged and elderly individuals, and total tau, β-amyloid 40 and 42 for comparison.

METHODS

We included 3,895 participants (71.78 years [SD = 7.37], 53.4% women) from the population-based Rotterdam Study. Between 2002 and 2005, NfL, total tau, β-amyloid 40 and β-amyloid 42 were determined in blood and depressive symptoms were measured with the Center for Epidemiologic Studies Depression scale (CES-D). Incident depressive events (clinically relevant depressive symptoms, depressive syndromes, major depressive disorders) were measured prospectively with the Center for Epidemiologic Studies Depression, a clinical interview and follow-up of medical records over a median follow-up of 7.0 years (interquartile range 1.80). We used linear and Cox proportional hazard regression models.

RESULTS

Each log2 pg./mL increase in NfL was cross-sectionally associated with more depressive symptoms (adjusted mean difference: 0.32, 95% CI 0.05-0.58), as well as with an increased risk of any incident depressive event over time (hazard ratio: 1.22, 95% CI 1.01-1.47). Further, more amyloid-β 40 was cross-sectionally associated with more depressive symptoms (adjusted mean difference: 0.70, 95% CI 0.15-1.25).

CONCLUSION

Higher levels of NfL are cross-sectionally associated with more depressive symptoms and a higher risk of incident depressive events longitudinally. The association was stronger for NfL compared to other plasma biomarkers, suggesting a potential role of neuroaxonal damage in developing late-life depression.

Identification of core genes, critical signaling pathways, and potential drugs for countering BPA-induced hippocampal neurotoxicity in male mice

Although the neurotoxicity of the common chemical bisphenol A (BPA) to the mouse hippocampus has been often reported, the mechanism underlying BPA-induced depression-like behavior in mice remains unclear. We evaluated BPA's role in inducing depressive-like behavior by exposing male mice to different BPA concentrations (0, 0.01, 0.1, and 1 μg/mL) and using the forced swimming test (FST) and tail suspension test (TST). We aimed to identify critical gene and anti-BPA-neurotoxicity compounds using RNA sequencing combined with bioinformatics analysis. Our results showed that 1 μg/mL BPA exposure increased mouse immobility during the FST and TST. Based on BPA-induced hippocampal transcriptome changes, we identified NADH: ubiquinone oxidoreductase subunit AB1 (Ndufab1) as a critical and potential therapeutic target gene, and Ndufab1 mRNA and protein levels were downregulated in the BPA-exposed groups. Furthermore, molecular docking identified phenelzine as a compound that could counteract BPA-related neurotoxicity. Conclusively, our analyses confirmed that BPA triggers depressive behavior in male mice by downregulating Ndufab1 expression and suggested that phenelzine might reduce BPA-induced neurotoxicity.

Is Living with Persons with Dementia and Depression Correlated to Impacts on Caregivers? A Scoping Review

Caregivers of persons with dementia and depression experience adverse effects associated with their role. The aim of this scoping review was to identify the challenges faced by caregivers of people with dementia and depression, along with interventions to support them. The MEDLINE®, Embase and PsycINFO databases were searched using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method. Grey literature was assessed using the Canadian Agency for Drugs and Technologies in Health's Gray Matter tool.The population consisted of caregivers of people with dementia and depression; the concept was to identify the negative impacts that caregivers experience and whether there are interventions to reduce them; the context was any study design targeting family or friends who were caregivers. A total of 12,835 citations were identified; 139 studies were included. Dementia and depression have variable impacts on outcomes experienced by caregivers, including burden/strain (n = 52), depression (n = 27), distress (n = 53), quality of life (n = 5) and health/well-being (n = 9). Pharmacological and non-pharmacological interventions have mixed effects. This study is important considering that depression in people with dementia is associated with caregiver distress. The use of a variety of non-pharmacological interventions could be beneficial to the latter.

Risk of Late-Onset Depression and Cognitive Decline: Results From Inflammatory Proteome Analyses in a Prospective Population-Based Cohort Study

OBJECTIVE

Research suggests that inflammation is linked to both late-onset depression (LOD) and cognitive decline, and that LOD might have biological underpinnings differentiating it from recurrent depression. Evidence from inflammatory proteome analyses in large prospective cohorts is scarce. The aim of this study was to assess whether and which inflammation-related biomarkers are associated with LOD, recurrent depression, and cognitive decline due to vascular pathology (vascular dementia).

DESIGN

Ongoing population-based cohort study of older adults followed for up to 17 years with regard to clinical diagnosis of various age-related diseases (ESTHER study, n = 9,940).

SETTING

Longitudinal cohort started in 2000-2002 in a community setting in Saarland, a southwestern German state.

PARTICIPANTS

Subgroup of randomly selected participants of the ESTHER study (n = 1,665).

MEASUREMENTS

Inflammatory biomarkers were measured with the Olink Target 96 in baseline samples.

RESULTS

Out of 78 biomarkers interleukin 10 (IL-10) and C-C chemokine ligand 4 (CCL4) were associated with significantly increased risk of LOD after multiple testing correction. Hazard ratios (95-confidence interval) per 1 standard deviation increase were 1.37 (1.15-1.63) for IL-10 and 1.34 (1.13-1.59) for CCL4. None of the inflammatory markers was associated with recurrent depression. The dose-response analysis showed a similar monotonic risk increase for LOD and vascular dementia with increasing IL-10 levels.

CONCLUSION

These results suggest that inflammatory markers are involved in the etiology of LOD, but not of recurrent depression and that LOD and vascular dementia might share common inflammatory etiology with respect to IL-10.

Mindfulness-based cognitive therapy for depression in people with dementia: A qualitative study on participant, carer and facilitator experiences

Background

Depression in dementia is common and associated with negative health outcomes. Mindfulness-based cognitive therapy is a recommended treatment of choice for recurrent depression, but its use for depression in dementia is yet to be assessed.

Objective

This study aimed to investigate the experiences of people with depression and dementia who participated in the mindfulness-based cognitive therapy intervention and those of their carers and facilitators.

Methods

This qualitative study was nested within a randomised controlled feasibility study. Semi-structured interviews were conducted with 18 people (eight people with dementia and depression, six carers and four course facilitators). Thematic analysis was used to analyse the data.

Findings

Several beneficial effects of mindfulness-based cognitive therapy were described. These were a sense of shared suffering among the group, greater present moment focus and awareness, various positive emotional changes, including greater self-compassion, and benefits for carers, such as the reduction of anxiety. Specific aspects of the programme were identified as particularly useful, including facilitator characteristics and certain mindfulness practices. Carer involvement, cognitive difficulties and barriers to home practice influenced engagement with the course. Facilitators described adaptations made to mindfulness-based cognitive therapy and suggested additional modifications for future groups.

Conclusion

Results of this process evaluation suggest that mindfulness-based cognitive therapy is a potentially useful intervention for people with depression in dementia, but that further adaptation of the intervention is required to make the programme suitable for this clinical population.

Dementia, Subtype of Seizures, and the Risk of New Onset Seizures: A Cohort Study

BACKGROUND

Seizure disorders have been identified in patients suffering from different types of dementia. However, the risks associated with the seizure subtypes have not been characterized.

OBJECTIVE

To compare the occurrence and risk of various seizure subtypes (focal and generalized) between patients with and without a dementia diagnosis.

METHODS

Data from 40.7 million private insured patient individual electronic health records from the U.S., were utilized. Patients 60 years of age or more from the Optum Insight Clinformatics-data Mart database were included in this study. Using ICD-9 diagnoses, the occurrence of generalized or focal seizure disorders was identified. The risk of new-onset seizures and the types of seizures associated with a dementia diagnosis were estimated in a cohort of 2,885,336 patients followed from 2005 to 2014. Group differences were analyzed using continuity-adjusted chi-square and hazard ratios with 95%confidence intervals calculated after a logistic regression analysisResults:A total of 79,561 patient records had a dementia diagnosis, and 56.38%of them were females. Patients with dementia when compared to those without dementia had higher risk for seizure disorders [Hazard ratio (HR) = 6.5 95%CI = 4.4-9.5]; grand mal status (HR = 6.5, 95%CI = 5.7-7.3); focal seizures (HR = 6.0, 95%CI = 5.5-6.6); motor simple focal status (HR = 5.6, 95%CI = 3.5-9.0); epilepsy (HR = 5.0, 95%CI = 4.8-5.2); generalized convulsive epilepsy (HR = 4.8, 95%CI = 4.5-5.0); localization-related epilepsy (HR = 4.5, 95%CI = 4.1-4.9); focal status (HR = 4.2, 95%CI = 2.9-6.1); and fits convulsions (HR = 3.5, 95%CI = 3.4-3.6).

CONCLUSION

The study confirms that patients with dementia have higher risks of generalized or focal seizure than patients without dementia.

Amitriptyline interferes with autophagy-mediated clearance of protein aggregates via inhibiting autophagosome maturation in neuronal cells

Amitriptyline is a tricyclic antidepressant commonly prescribed for major depressive disorders, as well as depressive symptoms associated with various neurological disorders. A possible correlation between the use of tricyclic antidepressants and the occurrence of Parkinson's disease has been reported, but its underlying mechanism remains unknown. The accumulation of misfolded protein aggregates has been suggested to cause cellular toxicity and has been implicated in the common pathogenesis of neurodegenerative diseases. Here, we examined the effect of amitriptyline on protein clearance and its relevant mechanisms in neuronal cells. Amitriptyline exacerbated the accumulation of abnormal aggregates in both in vitro neuronal cells and in vivo mice brain by interfering with the (1) formation of aggresome-like aggregates and (2) autophagy-mediated clearance of aggregates. Amitriptyline upregulated LC3B-II, but LC3B-II levels did not increase further in the presence of NH₄Cl, which suggests that amitriptyline inhibited autophagic flux rather than autophagy induction. Amitriptyline interfered with the fusion of autophagosome and lysosome through the activation of PI3K/Akt/mTOR pathway and Beclin 1 acetylation, and regulated lysosome positioning by increasing the interaction between proteins Arl8, SKIP, and kinesin. To the best of our knowledge, we are the first to demonstrate that amitriptyline interferes with autophagic flux by regulating the autophagosome maturation during autophagy in neuronal cells. The present study could provide neurobiological clue for the possible correlation between the amitriptyline use and the risk of developing neurodegenerative diseases.

Depression-an underrecognized target for prevention of dementia in Alzheimer's disease

It is broadly acknowledged that the onset of dementia in Alzheimer's disease (AD) may be modifiable by the management of risk factors. While several recent guidelines and multidomain intervention trials on prevention of cognitive decline address lifestyle factors and risk diseases, such as hypertension and diabetes, a special reference to the established risk factor of depression or depressive symptoms is systematically lacking. In this article we review epidemiological studies and biological mechanisms linking depression with AD and cognitive decline. We also emphasize the effects of antidepressive treatment on AD pathology including the molecular effects of antidepressants on neurogenesis, amyloid burden, tau pathology, and inflammation. We advocate moving depression and depressive symptoms into the focus of prevention of cognitive decline and dementia. We constitute that early treatment of depressive symptoms may impact on the disease course of AD and affect the risk of developing dementia and we propose the need for clinical trials.

Incident depression and mortality among people with different types of dementia: results from a longitudinal cohort study

PURPOSE

The aim of this study was to investigate the independent and combined association of incident depression and dementia with mortality and to explore whether the magnitude of the association varies according to different types of dementia, including Alzheimer's disease and vascular dementia.

METHODS AND DESIGN

The study was based on a population-based longitudinal cohort consisting of 9940 participants at baseline and followed for over 14 years. The sample used for the analyses included 6114 participants with available information on diagnosis of incident dementia and depression. For survival analyses, Cox regression models with incident dementia (n = 293; 5%) and incident depression (n = 746; 12%) as time-dependent variables were used.

RESULTS

Cox models adjusted for relevant confounders indicated that comorbidity of incident vascular dementia and incident depression was associated with a much higher mortality risk (HR 6.99; 95% CI 3.84-12.75) than vascular dementia in the absence of depression (HR 2.80; 95% CI 1.92-4.08). In contrast, estimates for comorbidity of Alzheimer's disease and depression were slightly lower than those for Alzheimer in absence of depression (HR 3.56; 95% CI 1.83-6.92 and HR 4.19; 95% CI 2.97-5.90, respectively). Incident depression in the absence of incident dementia was only weakly associated with mortality.

CONCLUSIONS

These findings indicate that depression and vascular dementia might have synergistic effects on mortality. The results have relevant public health implications for prevention, routine screening for and early treatment of depression among older people, especially those at risk of vascular dementia.

Prevalence of Depression, Anxiety and PTSD in People with Dementia: a Systematic Review and Meta-Analysis

There appears to be a link between depression/anxiety/PTSD and dementia, although the evidence is incomplete and the reason is unclear. Mental illness may cause dementia or may be prodromal or comorbid with dementia, or dementia may trigger a relapse of symptoms in individuals with a history of mental illness. This study examined the link between depression/anxiety/PTSD and dementia by evaluating the prevalence of these disorders in people with dementia, relative to their healthy peers. Existing meta-analyses have examined the prevalence of clinically-significant depression and anxiety in Alzheimer's disease (AD), and depression in frontotemporal dementia (FTD), but have not considered vascular dementia (VaD), dementia with Lewy bodies (DLB), PTSD, or anxiety in FTD. The current meta-analysis compared the prevalence of clinically-significant depression, anxiety and PTSD in the four most common types of dementia (AD, VaD, DLB, FTD) and in unspecified dementia to that of healthy controls (PROSPERO number: CRD42017082086). PubMed, EMBASE, PsycINFO and CINAHL database searches identified 120 eligible studies. Prevalence rates were calculated for depression and anxiety in AD, VaD, DLB, FTD, unspecified dementia, and controls. PTSD data were only available for unspecified dementia. Subgroup analyses indicated that depression, but not anxiety, was more prevalent in people with dementia compared to controls; however, the anxiety analyses were probably under-powered. The results support a link between depression and dementia; however, the link between anxiety or PTSD and dementia remains unclear due to insufficient data. Longitudinal data is now needed to clarify whether depression/anxiety/PTSD may be risk factors for dementia.

Caregiver burden in Alzheimer's disease: Moderation effects of social support and mediation effects of positive aspects of caregiving

OBJECTIVES

Although there are many studies on the relationship between patient-related factors and negative caregiver outcomes, the specifics of this relationship are poorly understood. We aimed to examine whether caregiver social support moderated the relationship between patient factors and negative outcomes for caregivers of community-dwelling older adults with Alzheimer's disease (AD), and whether positive aspects of caregiving mediated this relationship.

METHODS

We conducted a cross-sectional study of patients diagnosed with AD from 2 hospitals and 3 communities in Taiyuan, China, and their caregivers. Latent moderated structural equations and the bias-corrected percentile bootstrap method were used to estimate the parameters of moderating and mediating effects, respectively.

RESULTS

Social support significantly moderated the effects of AD patient cognitive function (P < 0.001) and depression (P = 0.001) on caregiver burden. Positive aspects of caregiving completely mediated the association between patient depression and caregiver burden (P = 0.006), caregiver anxiety (P = 0.007), and caregiver depression (P = 0.034).

CONCLUSIONS

The findings identify social support as a moderator and positive aspects of caregiving as a mediator of the relationship between patient-related factors and negative caregiver outcomes. The results suggest that health care providers must offer more effective social support for caregivers. In addition, prompt identification of patient and caregiver emotional states could help to improve quality of life.

Depression in dementia with Lewy bodies: A comparison with Alzheimer's disease

BACKGROUND

Depression is highly associated with dementia, and this study will compare the frequencies, severity, and symptoms of depression between dementia with Lewy bodies (DLB) and Alzheimer's disease (AD).

METHODS

Frequency of depression was determined according to the DSM-IV criteria for major depression or the National Institute of Mental Health criteria for depression in AD (NIMH-dAD). Severity of depression were assessed using the Hamilton Depression Rating Scale, the Cornell Scale for Depression in Dementia, and the depression subscale in Neuropsychiatric Inventory. The rates of depressive symptoms were compared between AD and DLB.

RESULTS

A total of 312 patients were investigated (AD/DLB = 241/71). The frequency of major depression was significantly higher (p = 0.017) in DLB (19.7%) than in AD (8.7%). The higher frequency of depression in DLB was not reproduced by using the NIMH-dAD criteria (DLB: AD = 43.7%: 33.2%; p = 0.105). The severity of depression was higher in DLB than in AD according to the Hamilton Depression Rating Scale (p < 0.001) and the Cornell Scale for Depression in Dementia (p < 0.001). Among depressive symptoms, pervasive anhedonia had the highest odds ratio in DLB compared with AD.

CONCLUSION

This is the first study using the NIMH-dAD criteria to investigate the frequency of depression in DLB. Our study shows that co-morbid major depression is more frequent in DLB than in AD. Pervasive anhedonia had the greatest value for the differential diagnosis of depression between DLB and AD.

Trajectories of Depressive Symptomatology in Rural Memory Clinic Patients between Baseline Diagnosis and 1-Year Follow-Up

BACKGROUND/AIMS

To investigate the prevalence and trajectories of depressive symptomatology at 1-year follow-up, and the severity of depressive symptoms, by dementia diagnostic group, as well as to determine the predictors of depressive symptomatology at 1-year follow-up.

METHODS

In rural and remote patients of an interdisciplinary memory clinic between 2004 and 2014, 144 patients diagnosed with no cognitive impairment (NCI), mild cognitive impairment, dementia due to Alzheimer's disease (AD), or non-AD dementia completed the Center for Epidemiologic Studies of Depression Scale to assess depressive symptomatology at both time points.

RESULTS

Among patients with data at both time points, persistence of depressive symptomatology at follow-up occurred in 22.2%, remission in 17.4%, incidence in 13.2%, and absence in 47.2%. The prevalence of depressive symptomatology at baseline and persistence at follow-up were significantly greater in the NCI group than in the other diagnostic groups, but there were no differences in severity. Depressive symptomatology at follow-up was independently associated with depressive symptomatology, lower independence in activities of daily living, and lower self-rating of memory at baseline, as well as with decreased independence in activities of daily living between time points.

CONCLUSION

Future studies should further examine short-term postdiagnostic trajectories in depressive symptomatology in multiple dementia diagnostic groups to inform prognoses and treatment decisions.

Comorbid Medical Conditions in Vascular Dementia: A Matched Case-Control Study

The objective of the study was to compare the presence of comorbid medical conditions between patients with a vascular dementia (VaD) and a control group, from the Integrated Healthcare Information Services (IHCIS) database. VaD was defined by the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes 290.40, 290.4, 290.41, 290.42, and, 290.43. An individual matching method was used to select the controls, which were matched to cases on a 15:1 ratio by age, gender, type of health plan, and pharmacy benefits. Alzheimer's disease, any other dementia or cognitive deficits associated were considered exclusion criteria. Among the IHCIS patients 60 years of age or older and full year of eligibility during 2010, there were 898 VaD patients, from which 63.6% were women. Concurrent presence of cerebrovascular disease, atherosclerosis, heart failure, and atrial fibrillation were found at 12.6, 4.6, 2.8, and 1.7 times higher in VaD patients, respectively. Compared to controls, VaD patients had more septicemia, injuries, lung diseases including chronic obstructive pulmonary disease, and urinary diseases (all with df = 897,1; p < 0.0001). The present study confirms that these four medical comorbidities are frequent complications of VaD and physicians should be alert to the presence of them in patients with VaD.

Prevalence and covariates of elevated depressive symptoms in rural memory clinic patients with mild cognitive impairment or dementia

Background/Aims

To estimate the prevalence, severity, and covariates of depressive symptoms in rural memory clinic patients diagnosed with either mild cognitive impairment (MCI) or dementia.

Methods

In a cross-sectional study of 216 rural individuals who attended an interdisciplinary memory clinic between March 2004 and July 2012, 51 patients were diagnosed with MCI and 165 with either dementia due to Alzheimer's disease (AD) or non-AD dementia. The Center for Epidemiologic Studies of Depression Scale (CES-D) was used to estimate the severity and prevalence of clinically elevated depressive symptomatology.

Results

The prevalence of elevated depressive symptoms was 51.0% in the MCI patients and 30.9% in the dementia patients. Depressive symptoms were more severe in the MCI patients than in the dementia patients. Elevated depressive symptoms were statistically associated with younger age for the MCI group, with lower self-rated memory for the dementia group, and with increased alcohol use and lower quality of life ratings for all patients. In the logistic regression models, elevated depressive symptoms remained negatively associated with self-rated memory and quality of life for the patients with dementia, but significant bivariate associations did not persist in the MCI group.

Conclusions

The high prevalence and severity of depressive symptoms among rural memory clinic patients diagnosed with either MCI or dementia warrant continued investigation.

Monoaminergic neurotransmitter alterations in postmortem brain regions of depressed and aggressive patients with Alzheimer's disease

Depression and aggression in Alzheimer's disease (AD) are 2 of the most severe and prominent neuropsychiatric symptoms (NPS). Altered monoaminergic neurotransmitter system functioning has been implicated in both NPS, although their neurochemical etiology remains to be elucidated. Left frozen hemispheres of 40 neuropathologically confirmed AD patients were regionally dissected. Dichotomization based on depression and aggression scores resulted in depressed/nondepressed (AD + D/AD - D) and aggressive/nonaggressive (AD + Agr/AD - Agr) groups. Concentrations of dopamine, serotonin (5-HT), (nor)epinephrine ((N)E), and respective metabolites were determined using reversed-phase high-performance liquid chromatography. Significantly lower 3-methoxy-4-hydroxyphenylglycol (MHPG) and higher homovanillic acid levels were observed in Brodmann area (BA) 9 and 10 of AD + D compared with AD - D. In AD + Agr, 5-hydroxy-3-indoleacetic acid (5-HIAA) levels in BA9, 5-HIAA to 5-HT ratios in BA11, and MHPG, NE, and 5-HIAA levels in the hippocampus were significantly decreased compared with AD - Agr. These findings indicate that brain region-specific altered monoamines and metabolites may contribute to the occurrence of depression and aggression in AD.

Factors associated with caregiver burden in patients with Alzheimer's disease

OBJECTIVE

Caregivers for patients with Alzheimer's disease (AD) suffer from psychological and financial burdens. However, the results of the relationship between burden and cognitive function, performance of activities of daily living, and depressive symptoms have remained inconsistent. Therefore, the aim of this study was to examine which factors are more significant predictors of heightened burden, cognitive impairment or functional decline, besides neuropsychiatric symptoms.

METHODS

A cross-sectional study was conducted in a sample comprised of 1,164 pairs of patients with AD and caregivers from the Clinical Research of Dementia of South Korea study cohorts. The cognitive function of each sub-domain, functional impairments, depressive symptoms, and caregiver burden were assessed using the dementia version of Seoul Neuropsychological Screening Battery (SNSB-D), Barthel Index for Daily Living Activities (ADL), Seoul-Instrumental Activities of Daily Living (S-IADL), the Clinical Dementia Rating Sum of Box (CDR-SB), the Global Deterioration Scale (GDS), the Korean version of the Neuropsychiatric Inventory (K-NPI), and the 15-item Geriatric Depression Scale.

RESULTS

We found that higher severity (higher CDR-SB and GDS scores) and more functional impairment (lower ADL and higher S-IADL scores) were significantly associated with higher caregiver burden. In addition, depressive symptoms of patients (higher Geriatric Depression Scale scores) were associated with higher caregiver burden.

CONCLUSION

Therefore, interventions to help maintain activities of daily living in patients with AD may alleviate caregiver burden and improve caregiver well-being.

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.

Do Alzheimer's disease (AD) and subcortical ischemic vascular dementia (SIVD) progress differently?

Our study aimed to compare cognitive status and declines in AD with/without small vessel disease (SVD) and SIVD at baseline and 1-year follow-up. Patients with Alzheimer's disease without small vessel disease (AD(-)SVD) (n=148), Alzheimer's disease with small vessel disease (AD(+)SVD) (n=94) and SIVD (n=60) were recruited from database of multiple centers in Korea. Basic demographics and detailed neuropsychological results were compared. AD, regardless of SVD, showed worse memory and better executive function than SIVD at baseline. Mini-Mental State Examination scores and visual memory function declined more in AD than those in SIVD whereas Barthel Activities of Daily Living (B-ADL) scores declined more in SIVD. AD showed different patterns of cognitive impairment compared with SIVD. After 1 year, AD showed more rapid cognitive decline in some domains. Further investigations with longer follow-up duration may be needed to confirm the cumulative effects of SVD in AD and different patterns of decline between AD and SIVD.

The association between physical morbidity and subtypes of severe depression

BACKGROUND

Physical illness and depression are related, but the association between specific physical diseases and diagnostic subtypes of depression remains poorly understood. This study aimed to clarify the relationship between a number of physical diseases and the nonpsychotic and psychotic subtype of severe depression.

METHODS

This is a historical prospective cohort study. The study population consisted of all patients diagnosed with ICD-10 severe depression, either nonpsychotic or psychotic subtype, in Danish psychiatric hospitals between 1994 and 2008. The patients' history of physical disease was assessed using the Danish National Patient Register. Using logistic regression it was investigated whether specific physical diseases were associated with relative increased risk for subsequent development of either the nonpsychotic or psychotic depressive subtype.

RESULTS

A total of 24,173 patients with severe depression were included in the study. Of those, 8,260 (34%) were of the psychotic subtype. A history of the following physical diseases, as opposed to their absence, increased the relative risk for subsequent development of the nonpsychotic compared to the psychotic depressive subtype [adjusted incidence odds ratio (AIOR) nonpsychotic vs. psychotic]: ischemic heart disease (AIOR = 1.3, p < 0.001), hypertension (AIOR = 1.2, p = 0.008), stroke (AIOR = 1.2, p = 0.042) and chronic lower pulmonary disease (AIOR = 1.2, p = 0.005). The total load of physical disease also increased the relative risk of nonpsychotic depression [AIOR = 1.05 (per disease), p = 0.001].

CONCLUSIONS

This study revealed that, in severe depression, a history of physical disease increased the relative risk of the nonpsychotic rather than the psychotic subtype.

Dysthymia and depression increase risk of dementia and mortality among older veterans

OBJECTIVE

To determine whether less severe depression spectrum diagnoses such as dysthymia, as well as depression, are associated with risk of developing dementia and mortality in a "real-world" setting.

DESIGN

Retrospective cohort study conducted using the Department of Veterans Affairs (VA) National Patient Care Database (1997-2007).

SETTING

VA medical centers in the United States.

PARTICIPANTS

A total of 281,540 veterans aged 55 years and older without dementia at study baseline (1997-2000).

MEASUREMENTS

Depression status and incident dementia were ascertained from International Classification of Diseases, Ninth Revision codes during study baseline (1997-2000) and follow-up (2001-2007), respectively. Mortality was ascertained by time of death dates in the VA Vital Status File.

RESULTS

Ten percent of veterans had baseline diagnosis of depression and nearly 1% had dysthymia. The unadjusted incidence of dementia was 11.2% in veterans with depression, 10.2% with dysthymia and 6.4% with neither. After adjusting for demographics and comorbidities, patients diagnosed with dysthymia or depression were twice as likely to develop incident dementia compared with those with no dysthymia/depression (adjusted dysthymia hazard ratio [HR]: 1.96, 95% confidence interval [CI]: 1.71-2.25; and depression HR: 2.18, 95% CI: 2.08-2.28). Dysthymia and depression also were associated with increased risk of death (31.6% dysthymia and 32.9% depression versus 28.5% neither; adjusted dysthymia HR: 1.41, 95% CI: 1.31-1.53; and depression HR: 1.47, 95% CI: 1.43-1.51).

CONCLUSIONS

Findings suggest that older adults with dysthymia or depression need to be monitored closely for adverse outcomes. Future studies should determine whether treatment of depression spectrum disorders may reduce risk of these outcomes.

The complex relationship between depression and dementia

Dementia and depression are mental health problems that are commonly encountered in neuropsychiatric practice in the elderly. Approximately, half of the patients with late-onset depression have cognitive impairment. The prevalence of depression in dementias has been reported to be between 9 and 68%. Depression has been both proposed to be a risk factor for dementia as well as a prodrome of dementia. This article is a selective literature review of the complex relationship between the two conditions covering definitions, epidemiology, related concepts, treatment, and emerging biomarkers. The methodological issues and the mechanisms underlying the relationship are also highlighted. The relationship between the two disorders is far from conclusive.