Neuropsychological functioning and MRI signal hyperintensities in geriatric depression

Sleep Time and Depression Symptoms as Predictors of Cognitive Development Among Adolescents: A Cross-Lagged Study From China

Sleep time and depression symptoms are important factors affecting cognitive development in adolescents. Based on the China Education Panel Survey (CEPS) database, this study used a two-wave cross-lagged model to examine the bidirectional relationship between sleep time, depression symptoms, and cognitive development. Descriptive statistics showed that Chinese adolescents' cognitive development increased significantly from 7th to 8th grade in junior high school, but unfortunately, their depression level and average sleep time per night demonstrated a slightly deteriorating trend. Correlation analysis showed that there was a relatively stable negative correlation between cognitive development, sleep time, and depression symptoms. Moreover, the cross-lagged model revealed that there was a bidirectional relationship between cognitive development and sleep time, a bidirectional relationship between depression symptoms and sleep time, and a unidirectional relationship between depression symptoms and cognitive development. Male adolescents in the subgroup were consistent with the total sample. Among female adolescents, only cognitive development and sleep time have a bidirectional relationship, while depression symptoms and cognitive development, and depression symptoms and sleep time have a unidirectional relationship. Therefore, it is of significance to take targeted action to promote cognitive development and healthy growth in adolescents worldwide.

Confining the Concept of Vascular Depression to Late-Onset Depression: A Meta-Analysis of MRI-Defined Hyperintensity Burden in Major Depressive Disorder and Bipolar Disorder

Background: The vascular depression hypothesis emphasizes the significance of vascular lesions in late-life depression. At present, no meta-analytic model has investigated whether a difference in hyperintensity burden compared to controls between late-life and late-onset depression is evident. By including a substantial number of studies, focusing on a meaningful outcome measure, and considering several moderating and control variables, the present meta-analysis investigates the severity of hyperintensity burden in major depressive disorder (MDD) and bipolar disorder (BD). A major focus of the present meta-analysis refers to the role of age at illness onset. It is analyzed whether late-onset rather than late-life depression characterizes vascular depression. Method: In total, 68 studies were included in the meta-analysis and a multilevel random effects model was calculated using Hedges' g as the effect size measure. Results: The severity of hyperintensity burden was significantly greater in the patient group compared to the control group. This effect was evident regarding the whole patient group (g = 0.229) as well as both depression subgroups, with a significantly greater effect in BD (g = 0.374) compared to MDD (g = 0.189). Hyperintensity burden was more pronounced in late-onset depression than in early-onset depression or late-life depression. A considerable heterogeneity between the included studies was observed, which is reflected by the large variability in effects sizes. Conclusion: In conclusion, the present meta-analysis underscores the association of hyperintensities with MDD and BD. Especially late-onset depression is associated with an increased hyperintensity burden, which is in line with the vascular depression hypothesis. The results suggest that it might be more feasible to confine the concept of vascular depression specifically to late-onset depression as opposed to late-life depression. Further research is needed to understand the causal mechanisms that might underlie the relation between hyperintensity burden and depression.

Depression related cerebral pathology and its relationship with cognitive functioning: A systematic review

BACKGROUND

Depression's relationship with cerebral abnormalities and cognitive decline is temporally dynamic. Despite clear clinical utility, understanding depression's effect on cerebral structures, cognitive impairment and the interaction between these symptoms has had limited consideration.

METHODS

This review summarised studies examining a clinical depression diagnosis or validated scales measuring depressive symptoms, data concerning amyloid-beta (Aβ) levels, brain structure and function focusing on hippocampal alterations, or white matter hyperintensities (WMH), and at least one validated neuropsychological test. Online database searches of: PsycINFO, EMBASE, MEDLINE, and Scopus were conducted to identify potential articles.

RESULTS

While depression was consistently associated with cross-sectionally cognitive decline across multiple domains, the neuropathological basis of this dysfunction remained unclear. Hippocampal, frontal, and limbic dysfunction as well as cortical thinning, WMH, and Aβ burden all provide inconsistent findings, likely due to depression subtypes. The consistency of these findings additionally decreases when examining this relationship longitudinally, as these results are further confounded by pre-dementia states. The therapeutic interventions examined were more efficacious in the younger compared with the older samples, who were characterised by greater WMH and Aβ burden.

LIMITATIONS

The limited number of longitudinal and interventional studies in addition to the heterogeneity of the samples restricts their generalisability.

CONCLUSIONS

Symptomatological differences between early-onset and late-onset depression (EOD and LOD) appear crucial in understanding whether late-life depression is the primary or secondary source of cerebral pathology. Though severe cognitive impairments and clearer neuropathological underpinnings are more characteristic of LOD than EOD, the inconsistency of valid biomarkers remains problematic.

Overlay of Late-Life Depression and Cognitive Impairment

This article appraises several facets of the linkage between depression and cognitive impairment, including dementia, mild cognitive impairment, and vascular dementia. Potential mechanisms for this association are examined. This review was crafted to be extensive but not exhaustive. The authors searched PubMed, using the terms depression, late-life depression, cognitive impairment, and dementia. Articles included are seminal articles from the field as well as representative, heuristic studies. A link between depression and cognitive impairment was found. Depression likely serves as both a risk factor and a prodromal symptom of dementia. Mechanisms whereby depression could induce cognitive impairment include hippocampal atrophy, alterations in glucocorticoid secretion, cerebrovascular compromise, deposition of β-amyloid plaques, chronic inflammation, apolipoprotein E status, and deficits of nerve growth factors. This article will benefit the practicing clinician by increasing awareness of the links between depression and dementia and encouraging greater emphasis on screening for cognitive impairment among individuals with depression or a history of depression.

The double burden of age and major depressive disorder on the cognitive control network

Poor cognitive control (CC) is common among older individuals with major depressive disorder (OMDD). At the same time, studies of CC in OMDD with fMRI are relatively limited and often have small samples. The present study was conducted to further examine poor CC in OMDD with early onset depression, as well as to investigate the interactive effects of MDD and aging on cognitive control. Twenty OMDD, 17 older never-depressed comparisons (ONDC), 16 younger adults with MDD (YMDD), and 18 younger never-depressed comparisons (YNDC) participated. All participants completed the Go level of the Parametric Go/No-Go Test, which requires sustained attention and inhibitory control while undergoing functional MRI (fMRI). YNDC were faster in reaction times (RTs) to go targets relative to the other 3 groups, and the YMDD group was faster than the OMDD group. fMRI effects of both age and diagnosis were present, with greater activation in MDD, and in aging. Additionally, the interaction of age and MDD was also significant, such that OMDD exhibited greater recruitment of fronto-subcortical regions relative to older comparisons. These results are consistent with prior research reporting that OMDD recruit more fronto-striatal regions in order to perform at the same level as their never-depressed peers, here on a task of sustained attention and inhibitory control. There may be an interaction of cognitive aging and depression to create a double burden on the CC network in OMDD, including possible fronto-striatal compensation during CC that is unique to OMDD, as younger MDD individuals do not show this pattern.

Cognitive Deficits as a Mediator of Poor Occupational Function in Remitted Major Depressive Disorder Patients

Cognitive deficits in major depressive disorder (MDD) patients have been described in numerous studies. However, few reports have aimed to describe cognitive deficits in the remitted state of MDD and the mediational effect of cognitive deficits on occupational outcome. The aim of the current review is to synthesize the literature on the mediating and moderating effects of specific domains of cognition on occupational impairment among people with remitted MDD. In addition, predictors of cognitive deficits found to be vocationally important will be examined. Upon examination of the extant literature, attention, executive function and verbal memory are areas of consistent impairment in remitted MDD patients. Cognitive domains shown to have considerable impact on vocational functioning include deficits in memory, attention, learning and executive function. Factors that adversely affect cognitive function related to occupational accommodation include higher age, late age at onset, residual depressive symptoms, history of melancholic/psychotic depression, and physical/psychiatric comorbidity, whereas higher levels of education showed a protective effect against cognitive deficit. Cognitive deficits are a principal mediator of occupational impairment in remitted MDD patients. Therapeutic interventions specifically targeting cognitive deficits in MDD are needed, even in the remitted state, to improve functional recovery, especially in patients who have a higher risk of cognitive deficit.

Evaluation and follow-up of cognitive functions in patients with minor stroke and transient ischemic attack

BACKGROUND AND PURPOSE

We aimed to examine the incidence of cognitive impairment among patients with stroke, the associated risk factors, progression of the cognitive impairment, and the association between the localization of the lesion(s) as detected by magnetic resonance imaging and the affected areas of cognitive function.

METHODS

A total of 40 patients over 18 years of age enduring a transient ischemic stroke or minor stroke within the past 3 months who had a minimum life expectancy of 1 year were included in this study. Same number, age-, and sex-matched individuals were included as controls. Patients were inquired on the presence of risk factors for stroke. A series of neuropsychological test batteries were administered in patient and control subjects for assessing cognitive functions. These tests were readministered at 6 and 12 months of follow-up to assess the progression of cognitive functions.

RESULTS

In this study among the patients with stroke, a significant impairment was seen in multiple cognitive functional tests following ischemic stroke as compared to control groups. The most common risk factors for stroke included hypertension (72.5%), hyperlipidemia, and cigarette smoking. The number of cognitive domains with an impairment was highest (in four cognitive tests) among those with coronary artery disease and atrial fibrillation, followed by those who had a >50% stenosis in Doppler (three cognitive tests). These findings suggest that the frequency of risk factors associated with stroke does not correlate with the frequency of risk factors associated with cognitive dysfunction. The stroke localizations were classified among the patients with stroke and reviewed in accordance with cognitive impairment.

CONCLUSION

Neuropsychological tests, clinical findings, and imaging studies should be used to document the poststroke cognitive dysfunction.

Effects of psychiatric history on cognitive performance in old-age depression

Cognitive deficits in old-age depression vary as a function of multiple factors; one rarely examined factor is long-term psychiatric history. We investigated effects of psychiatric history on cognitive performance in old-age depression and in remitted persons. In the population-based Swedish National Study on Aging and Care in Kungsholmen study, older persons (≥60 years) without dementia were tested with a cognitive battery and matched to the Swedish National Inpatient Register (starting 1969). Participants were grouped according to current depression status and psychiatric history and compared to healthy controls (n = 96). Group differences were observed for processing speed, attention, executive functions, and verbal fluency. Persons with depression and psychiatric inpatient history (n = 20) and late-onset depression (n = 49) performed at the lowest levels, whereas cognitive performance in persons with self-reported recurrent unipolar depression (n = 52) was intermediate. Remitted persons with inpatient history of unipolar depression (n = 38) exhibited no cognitive deficits. Heart disease burden, physical inactivity, and cumulative inpatient days modulated the observed group differences in cognitive performance. Among currently depressed persons, those with inpatient history, and late onset performed at the lowest levels. Importantly, remitted persons showed no cognitive deficits, possibly reflecting the extended time since the last admission (m = 15.6 years). Thus, the present data suggest that cognitive deficits in unipolar depression may be more state- than trait-related. Information on profiles of cognitive performance, psychiatric history, and health behaviors may be useful in tailoring individualized treatment.

Structural imaging in late-life depression: association with mood and cognitive responses to antidepressant treatment

OBJECTIVES

Recent positron emission tomography studies of cerebral glucose metabolism have identified the functional neural circuitry associated with mood and cognitive responses to antidepressant treatment in late life depression (LLD). The structural alterations in these networks are not well understood. The present study used magnetic resonance (MR) imaging and voxel-based morphometry to evaluate the association between gray matter volumes and changes in mood symptoms and cognitive function with treatment with the antidepressant citalopram.

DESIGN

Open-label trial with baseline brain MR scan. Mood and cognitive assessments performed at baseline and during citalopram treatment.

SETTING

Outpatient clinics of an academic medical center.

PARTICIPANTS

17 previously unmedicated patients age 55 years or older with a major depressive episode and 17 non-depressed comparison subjects.

INTERVENTION

12-week trial of flexibly dosed citalopram.

MEASUREMENTS

Gray matter volumes, Hamilton Depression Rating Scale, California Verbal Learning Test, Delis-Kaplan Executive Function System.

RESULTS

In LLD, higher gray matter volumes in the cingulate gyrus, superior and middle frontal gyri, middle temporal gyrus, and precuneus was associated with greater mood improvement. Higher gray matter volumes in primarily frontal areas were associated with greater improvement in verbal memory and verbal fluency performance.

CONCLUSIONS

Associations with antidepressant induced improvements in mood and cognition were observed in several brain regions previously correlated with normalization of glucose metabolism after citalopram treatment in LLD. Future studies will investigate molecular mechanisms underlying these associations (e.g., beta-amyloid, inflammation, glutamate).

Cyr N, Lavretsky H. The patterns of cognitive and functional impairment in amnestic and non-amnestic mild cognitive impairment in geriatric depression

OBJECTIVES

Depressed older adults are at risk for the development of mild cognitive impairment (MCI), but few studies have characterized MCI subtypes in geriatric depression. The objective of this study was to identify the clinical patterns of MCI in late-life depression.

DESIGN

Baseline demographic, clinical, and neuropsychological test data collected as part of a randomized antidepressant trial for geriatric depression.

SETTING

UCLA-based outpatient clinic.

PARTICIPANTS

One hundred thirty-eight older adults with major depression.

MEASUREMENTS

A neuropsychological test battery and comprehensive evaluations of depression, apathy, quality of life, medical burden, and vascular risk factors.

RESULTS

Seventy-one participants (51%) had MCI and 67 (49%) were cognitively normal. Of subjects with MCI, 14 (20%) had amnestic MCI and 57 (80%) had non-amnestic MCI. Overall, patients with MCI had greater depression severity, poorer quality of life, and worse performance on the Mini-Mental State Exam than patients without MCI. Patients with non-amnestic MCI had significantly greater depression severity than patients without MCI. Across all subjects, depression severity correlated with impaired performance in language and visuospatial functioning.

CONCLUSION

Our findings suggest that MCI is associated with greater severity of depression, poorer quality of life, and worse global cognitive function. Overall, subtypes of MCI in geriatric depression differ in the patterns of functional impairment, which may require different therapeutic approaches.

Cognitive deficits in geriatric depression: clinical correlates and implications for current and future treatment

The purpose of this article is to identify the cognitive deficits commonly associated with geriatric depression and describe their clinical significance. The complex relationship between geriatric depression and dementia is summarized and possible shared mechanisms discussed. Evidence regarding whether the cognitive deficits in depression may be mitigated with medication or with computerized cognitive remediation is presented.

Cognitive performance in older elderly men with late-life depression and cardiovascular comorbidities: symptomatological correlation

BACKGROUND

Whether depression or cardiovascular disease would have a greater effect on worsening cognitive impairment in the burgeoning older elderly population is uncertain. Which disorder causes greater cognitive impairment was investigated.

METHODS

A cross section of 207 cognitively impaired older elderly (≥75 years old) men was recruited from outpatient clinics in southern Taiwan between 2004 and 2008. Their medical charts were reviewed for their history of medical illnesses, and those undergoing a current major depressive episode were screened using the Mini-International Neuropsychiatric Interview. Four groups of men were enrolled: 33 healthy controls (HC), 101 cognitively impaired patients with cardiovascular comorbidities (CVCs), 34 patients with late-life depression (LLD), and 49 patients with LLD and cardiovascular comorbidities (LLD + CVC). Several neuropsychological tests (e.g., Mini-Mental State Examination (MMSE), WCST, and Trail Making Test (TMT) parts A and B) were used to assess the participants.

RESULTS

Cognitive function scores were highest in the HC group and lowest in the LLD + CVC group. There were no significant differences between the two groups with LLD comorbidity, and LLD was mostly associated with cognitive performance. LLD + CVC group members had the lowest recall memory, but their overall MMSE score was not significantly different. Moreover, this group had a higher but nonsignificantly different perseverative error than did the LLD group. Similarly, the LLD + CVC group was nonsignificantly slower at the TMT-A and TMT-B tasks than was the LLD group.

CONCLUSIONS

LLD worsens neuropsychological function more than cardiovascular comorbidities do.

The vascular depression hypothesis: mechanisms linking vascular disease with depression

The 'Vascular Depression' hypothesis posits that cerebrovascular disease may predispose, precipitate or perpetuate some geriatric depressive syndromes. This hypothesis stimulated much research that has improved our understanding of the complex relationships between late-life depression (LLD), vascular risk factors, and cognition. Succinctly, there are well-established relationships between LLD, vascular risk factors and cerebral hyperintensities, the radiological hallmark of vascular depression. Cognitive dysfunction is common in LLD, particularly executive dysfunction, a finding predictive of poor antidepressant response. Over time, progression of hyperintensities and cognitive deficits predicts a poor course of depression and may reflect underlying worsening of vascular disease. This work laid the foundation for examining the mechanisms by which vascular disease influences brain circuits and influences the development and course of depression. We review data testing the vascular depression hypothesis with a focus on identifying potential underlying vascular mechanisms. We propose a disconnection hypothesis, wherein focal vascular damage and white matter lesion location is a crucial factor, influencing neural connectivity that contributes to clinical symptomatology. We also propose inflammatory and hypoperfusion hypotheses, concepts that link underlying vascular processes with adverse effects on brain function that influence the development of depression. Testing such hypotheses will not only inform the relationship between vascular disease and depression, but also provide guidance on the potential repurposing of pharmacological agents that may improve LLD outcomes.

Longitudinal studies of cerebral glucose metabolism in late-life depression and normal aging

OBJECTIVE

Late-life depression (LLD) has a substantial public health impact and is both a risk factor for and a prodrome of dementia. Positron emission tomography (PET) studies of cerebral glucose metabolism have demonstrated sensitivity in evaluating neural circuitry involved in depression, aging, incipient cognitive decline, and dementia. The present study evaluated the long term effects of a course of antidepressant treatment on glucose metabolism in LLD patients.

METHODS

Nine LLD patients and seven non-depressed control subjects underwent clinical and cognitive evaluations as well as brain magnetic resonance imaging and PET studies of cerebral glucose metabolism at baseline, after 8 weeks of treatment with citalopram for a major depressive episode (patients only), and at an approximately 2-year follow-up.

RESULTS

The majority of LLD patients were remitted at follow-up (7/9). Neither patients nor controls showed significant cognitive decline. The patients showed greater increases in glucose metabolism than the controls in regions associated with mood symptoms (anterior cingulate and insula). Both groups showed decreases in metabolism in posterior association cortices implicated in dementia.

CONCLUSIONS

Longitudinal changes in cerebral glucose metabolism are observed in controls and in LLD patients without significant cognitive decline that are more extensive than the decreases in brain volume. Longer duration follow-up studies and the integration of other molecular imaging methods will have implications for understanding the clinical and neurobiological significance of these metabolic changes.

Biological basis of late life depression

Late life depression (LLD) is an important area of research given the growing elderly population. The purpose of this review is to examine the available evidence for the biological basis of LLD. Structural neuroimaging shows specific gray matter structural changes in LLD as well as ischemic lesion burden via white matter hyperintensities. Similarly, specific neuropsychological deficits have been found in LLD. An inflammatory response is another possible underlying contributor to the pathophysiology of LLD. We review the available literature examining these multiple facets of LLD and how each may affect clinical outcome in the depressed elderly.

Change in cognitive functioning in depressed older adults following treatment with sertraline or nortriptyline

OBJECTIVE

The aim of this study was to compare the impact of nortriptyline to sertraline on change in cognitive functioning in depressed older adults.

METHODS

We used pre-post neuropsychological data collected as part of a 12-week medication trial comparing sertraline to nortriptyline in the treatment of older adults with non-psychotic, unipolar major depression to examine change in cognitive functioning. Neuropsychological assessments included mental status (Mini-Mental Status Exam), psychomotor speed (Purdue Pegboard), attention (Continuous Performance Test, Trail Making Test A), executive functioning (Stroop Color/word Test, Trail Making Test B), and memory (Buschke Selective Reminding Test).

RESULTS

Within treatment groups, patients treated with sertraline improved only on verbal learning. This change did not depend on responder status. Between treatment groups, patients treated with sertraline improved more in verbal learning compared with patients treated with nortriptyline. Looking at change in cognition as a function of medication condition and responder status revealed that sertraline responders improved more in verbal learning compared with nortriptyline responders but not more than sertraline non-responders or nortriptyline non-responders. Nortriptyline responders were the only treatment by responder status group to show no improvement in verbal learning from baseline to endpoint.

CONCLUSIONS

Unexpectedly, nortriptyline responders showed no improvement in verbal learning as compared with patients treated with sertraline or nortriptyline non-responders. However, given the small sample sizes and number of statistical tests (potential for type 1 error), replication is warranted.

Semantic organizational strategy predicts verbal memory and remission rate of geriatric depression

OBJECTIVE

This study tests the hypothesis that the use of semantic organizational strategy during the free-recall phase of a verbal memory task predicts remission of geriatric depression.

METHODS

Sixty-five older patients with major depression participated in a 12-week escitalopram treatment trial. Neuropsychological performance was assessed at baseline after a 2-week drug washout period. The Hopkins Verbal Learning Test-Revised was used to assess verbal learning and memory. Remission was defined as a Hamilton Depression Rating Scale score of ≤ 7 for 2 consecutive weeks and no longer meeting the DSM-IV-TR criteria for major depression. The association between the number of clusters used at the final learning trial (trial 3) and remission was examined using Cox's proportional hazards survival analysis. The relationship between the number of clusters utilized in the final learning trial and the number of words recalled after a 25-min delay was examined in a regression with age and education as covariates.

RESULTS

Higher number of clusters utilized predicted remission rates (hazard ratio, 1.26 (95% confidence interval, 1.04-1.54); χ(2)  = 4.23, df = 3, p = 0.04). There was a positive relationship between the total number of clusters used by the end of the third learning trial and the total number of words recalled at the delayed recall trial (F(3,58) = 7.93; p < 0.001).

CONCLUSIONS

Effective semantic strategy use at baseline on a verbal list learning task by older depressed patients was associated with higher rates of remission with antidepressant treatment. This result provides support for previous findings indicating that measures of executive functioning at baseline are useful in predicting antidepressant response.

Diminished performance on neuropsychological testing in late life depression is correlated with microstructural white matter abnormalities

BACKGROUND

Traditional T2 weighted MR imaging results are non-specific for the extent of underlying white matter structural abnormalities present in late life depression (LLD). Diffusion tensor imaging provides a unique opportunity to investigate the extent and nature of structural injury, but has been limited by examining only a subset of regions of interest (ROI) and by confounds common to the study of an elderly population, including comorbid vascular pathology. Furthermore, comprehensive correlation of diffusion tensor imaging (DTI) measurements, including axial and radial diffusivity measurements, has not been demonstrated in the late life depression population.

METHODS

51 depressed and 16 non-depressed, age- and cerebrovascular risk factor-matched elderly subjects underwent traditional anatomic T1 and T2 weight imaging, as well as DTI. The DTI data were skeletonized using tract based spatial statistics (TBSS), and both regional and global analyses were performed.

RESULTS

Widespread structural abnormalities within white matter were detected in the LLD group, accounting for age, gender and education and matched for cerebrovascular risk factors and global T2 white matter hyperintensities (T2WMH). Regional differences were most prominent in uncinate and cingulate white matter and were generally characterized by an increase in radial diffusivity. Age-related changes particularly in the cingulate bundle were more advanced in individuals with LLD relative to controls. Regression analysis demonstrated significant correlations of regional fractional anisotropy and radial diffusivity with five different neuropsychological factor scores. TBSS analysis demonstrated a greater extent of white matter abnormalities in LLD not responsive to treatment, as compared to controls.

CONCLUSIONS

White matter integrity is compromised in late life depression, largely manifested by increased radial diffusivity in specific regions, suggesting underlying myelin injury. A possible mechanism for underlying myelin injury is chronic white matter ischemia related to intrinsic cerebrovascular disease. In some regions such as the cingulate bundle, the white matter injury related to late life depression appears to be independent of and compounded by age-related changes. The correlations with neuropsychological testing indicate the essential effects of white matter injury on functional status. Lastly, response to treatment may depend on the extent of white matter injury, suggesting a need for intact functional networks.

Depressive symptoms, brain volumes and subclinical cerebrovascular disease in postmenopausal women: the Women's Health Initiative MRI Study

OBJECTIVE

Late-life depressive symptoms (DS) increase the risk of incident mild cognitive impairment and probable dementia in the elderly. Our objectives were to examine the relationship between elevated DS and regional brain volumes including frontal lobe subregions, hippocampus and amygdala, and to determine whether elevated DS were associated with increased subclinical cerebrovascular disease in postmenopausal women.

METHODS

DS were assessed an average of 8years prior to structural brain MRI in 1372 women. The 8-item Burnam regression algorithm was used to define DS with a cut-point of 0.009. Adjusting for potential confounders, mean differences in total brain, frontal lobe subregions, hippocampus and amygdala volumes and total ischemic lesion volumes in the basal ganglia and the cerebral white and gray matter outside the basal ganglia were compared between women with and without DS.

RESULTS

Depressed women had lower baseline global cognition and were more likely to have prior hormone therapy history. After full adjustment, DS at baseline were associated with smaller superior and middle frontal gyral volumes. Hippocampal and amygdala volumes, and ischemic lesion volumes were similar in depressed and non-depressed women.

LIMITATIONS

Depression was not assessed based on semi-structured interview, and MRI scans were obtained cross-sectionally rather than longitudinally. Longitudinal MRI assessments will be necessary to define the temporal relationships between DS and frontal lobe volumes.

CONCLUSIONS

Elevated DS were associated with lower volumes in certain frontal lobe subregions but not in the medial temporal lobe structures. Our findings support the role of frontal lobe structures in late-life DS among women.

The vascular depression hypothesis: an update

Since being proposed as a unique subtype of late-life depression (LLD), the vascular depression hypothesis has received considerable research attention. Although this effort has generated considerable empirical support for the validity of the subtype, fundamental questions remain including how the illness is defined, whether cerebrovascular disease and executive dysfunction (ED) define two separate entities or one underlying subtype, and whether ED is responsible for poor response to antidepressant treatment. In this guest editorial, we explore these and other issues (i.e., the role of personality and social support, psychosocial treatments targeting cognitive abilities frequently impaired in LLD) using a number of important papers that are either directly or indirectly related to the vascular depression hypothesis. In so doing we highlight a range of critical problems facing the vascular depression hypothesis and the effort to establish the illness as a unique diagnostic entity in late-life.

MRI signal hyperintensities and treatment remission of geriatric depression

BACKGROUND

White matter abnormalities may interfere with limbic-cortical balance and contribute to chronic depressive syndromes in the elderly. This study sought to clarify the relationship of SH to treatment response. We hypothesized that patients who failed to remit during a 12-week controlled treatment trial of escitalopram would exhibit greater SH burden than patients who remitted.

METHODS

The participants were 42 non-demented individuals with non-psychotic major depression and 25 elderly comparison subjects. After a 2-week single blind placebo period, subjects who still had a Hamilton Depression Rating Scale (HDRS) of 18 or greater received escitalopram 10mg daily for 12 weeks. Remission was defined as a HDRS score of 7 or below for 2 consecutive weeks. FLAIR sequences were acquired on a 1.5 T scanner and total SH were quantified using a semi-automated thresholding method.

RESULTS

The patient sample consisted of 22 depressed patients who achieved remission during the study and 20 depressed patients who remained symptomatic. ANCOVA, with age and gender as covariates, revealed that depressed subjects had greater total SH burden relative to non-depressed controls. Furthermore, patients who failed to remit following escitalopram treatment had significantly greater SH burden than both patients who remitted and elderly comparison subjects, whereas SH burden did not differ between depressed patients who remitted and elderly comparison subjects.

LIMITATIONS

Patients were treated with a fixed dose of antidepressants and the index of SH is an overall measure that does not permit examination of the relationship of regional SH to treatment remission.

DISCUSSION

SH may contribute to a "disconnection state" both conferring vulnerability to and perpetuating late-life depression.

Distinct functional networks associated with improvement of affective symptoms and cognitive function during citalopram treatment in geriatric depression

Variability in the affective and cognitive symptom response to antidepressant treatment has been observed in geriatric depression. The underlying neural circuitry is poorly understood. This study evaluated the cerebral glucose metabolic effects of citalopram treatment and applied multivariate, functional connectivity analyses to identify brain networks associated with improvements in affective symptoms and cognitive function. Sixteen geriatric depressed patients underwent resting positron emission tomography (PET) studies of cerebral glucose metabolism and assessment of affective symptoms and cognitive function before and after 8 weeks of selective serotonin reuptake inhibitor treatment (citalopram). Voxel-wise analyses of the normalized glucose metabolic data showed decreased cerebral metabolism during citalopram treatment in the anterior cingulate gyrus, middle temporal gyrus, precuneus, amygdala, and parahippocampal gyrus. Increased metabolism was observed in the putamen, occipital cortex, and cerebellum. Functional connectivity analyses revealed two networks which were uniquely associated with improvement of affective symptoms and cognitive function during treatment. A subcortical-limbic-frontal network was associated with improvement in affect (depression and anxiety), while a medial temporal-parietal-frontal network was associated with improvement in cognition (immediate verbal learning/memory and verbal fluency). The regions that comprise the cognitive network overlap with the regions that are affected in Alzheimer's dementia. Thus, alterations in specific brain networks associated with improvement of affective symptoms and cognitive function are observed during citalopram treatment in geriatric depression.

Support for the vascular depression hypothesis in late-life depression: results of a 2-site, prospective, antidepressant treatment trial

CONTEXT

Research on vascular depression has used 2 approaches to subtype late-life depression, based on executive dysfunction or white matter hyperintensity severity.

OBJECTIVE

To evaluate the relationship of neuropsychological performance and white matter hyperintensity with clinical response in late-life depression.

DESIGN

Two-site, prospective, nonrandomized controlled trial.

SETTING

Outpatient clinics at Washington University and Duke University.

PARTICIPANTS

A total of 217 subjects aged 60 years or older met DSM-IV criteria for major depression, scored 20 or more on the Montgomery-Asberg Depression Rating Scale (MADRS), and received vascular risk factor scores, neuropsychological testing, and magnetic resonance imaging; they were excluded for cognitive impairment or severe medical disorders. Fazekas rating was conducted to grade white matter hyperintensity lesions. Intervention Twelve weeks of sertraline treatment, titrated by clinical response. Main Outcome Measure Participants' MADRS scores over time.

RESULTS

Baseline neuropsychological factor scores correlated negatively with baseline Fazekas scores. A mixed model examined effects of predictor variables on MADRS scores over time. Baseline episodic memory (P = .002), language (P = .007), working memory (P = .01), processing speed (P < .001), executive function factor scores (P = .002), and categorical Fazekas ratings (P = .05) predicted MADRS scores, controlling for age, education, age of onset, and race. Controlling for baseline MADRS scores, these factors remained significant predictors of decrease in MADRS scores, except for working memory and Fazekas ratings. Thirty-three percent of subjects achieved remission (MADRS < or =7). Remitters differed from nonremitters in baseline cognitive processing speed, executive function, language, episodic memory, and vascular risk factor scores.

CONCLUSIONS

Comprehensive neuropsychological function and white matter hyperintensity severity predicted MADRS scores prospectively over a 12-week treatment course with selective serotonin reuptake inhibitors in late-life depression. Baseline neuropsychological function differentiated remitters from nonremitters and predicted time to remission in a proportional hazards model. Predictor variables correlated highly with vascular risk factor severity. These data support the vascular depression hypothesis and highlight the importance of linking subtypes based on neuropsychological function and white matter integrity.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00045773.

The intersection of pharmacology, imaging, and genetics in the development of personalized medicine

We currently rely on large randomized trials and meta-analyses to make clinical decisions; this places us at a risk of discarding subgroup or individually specific treatment options owing to their failure to prove efficacious across entire populations. There is a new era emerging in personalized medicine that will focus on individual differences that are not evident phenomenologically. Much research is directed towards identifying genes, endophenotypes, and biomarkers of disease that will facilitate diagnosis and predict treatment outcome. We are at the threshold of being able to predict treatment response, primarily through genetics and neuroimaging. In this review we discuss the most promising markers of treatment response and adverse effects emerging from the areas of pharmacogenetics and neuroimaging in depression and schizophrenia.

Residual Cognitive Deficit in Adults with Depression who Recovered after 6-month Treatment: Stable versus State-Dependent Markers

BACKGROUND

Knowledge of depression-related disturbances in cognitive functioning is advancing, but little is known about the cognitive response to treatment for major depression, especially in younger adults. This study investigated the deficits in multiple cognitive domains in middle-aged patients with major depressive disorder (MDD), using a prospective follow-up study design.

METHODS

The sample consisted of 13 medication-free MDD patients and 13 education- and age-matched healthy controls. All subjects were administered clinical measures as well as a comprehensive neurocognitive test battery aimed at assessing multiple cognitive domains at the time of recruitment. Patients remitted after 6 months following treatment repeated the neurocognitive assessment.

RESULTS

There were significant differences between the depressed subjects and controls at baseline. MDD patients with remitted symptoms still showed significant deficits in executive function and motor function, but not in memory or attention domains. Patients had significant improvement in memory and attention domains only, once their depressive symptoms had subsided; while executive functioning as well as motor functioning remained unchanged.

CONCLUSIONS

Executive functioning and motor functioning deficits might be stable vulnerability indicators for MDD, and memory and attention impairment might serve as state-dependent indicators for MDD.

KEYWORDS

Major depressive disorder; Remission; Residual; Cognitive deficits; Follow-up.

Change in cognitive functioning following acute antidepressant treatment in late-life depression

OBJECTIVE

Selective Serotonin Reuptake Inhibitors (SSRIs) are the most commonly prescribed medications for geriatric depression. The association of late-life depression and cognitive impairment has been well documented. However, there have been few placebo-controlled trials examining the impact of SSRIs on cognitive functioning.

DESIGN

Prepost neuropsychological (NP) data collected as part of an 8-week, double-blind, placebo-controlled trial of citalopram in depressed patients aged 75 years and older were used to examine change in cognitive functioning.

SETTING

University-affiliated outpatient psychiatry clinics.

PARTICIPANTS

One hundred seventy-four community-dwelling men and women aged 75 years or older with nonpsychotic unipolar depression.

MEASUREMENTS

NP assessments included mental status (Mini-Mental State Examination), psychomotor speed (Wechsler Adult Intelligence Scale-III Digit Symbol Subtest), reaction time (Choice Reaction Time), visual-spatial skill (Judgment of Line Orientation), executive functioning (Stroop Color/Word Test), and memory (Buschke Selective Reminding Test).

RESULTS

Differences in the pattern of change by treatment group depended on responder status. Citalopram nonresponders were the only group to decline on verbal learning and psychomotor speed. Citalopram responders showed significant improvement in visuospatial functioning, when compared with nonresponders in either condition, but their improvement was not greater than responders on placebo. Citalopram responders showed greater improvement on psychomotor speed than citalopram nonresponders, but their improvement was not greater than placebo responders or nonresponders.

CONCLUSIONS

Medication may have a deleterious effect on some aspects of cognition among patients aged 75 years and older who have not responded. This suggests that patients should not be maintained on a medication if they have not had an adequate response.

The moderating role of personality factors in the relationship between depression and neuropsychological functioning among older adults

OBJECTIVE

Depression is often associated with decreased cognitive performance among older adults. The current study focused on the association of neuropsychological functioning and personality traits in depressed and non-depressed older adults.

METHODS

Data from 75 depressed and 103 non-depressed adults over the age of 60 were analyzed. All participants underwent standardized clinical assessment for depression prior to participation and completed the NEO-PI-R and a series of neuropsychological assessments.

RESULTS

A series of multiple linear regressions were conducted to examine the relationships between personality and neuropsychological performance among depressed and non-depressed older adults. Results indicated that higher Openness to Experience was related to better performance on Parts A and B of the Trail Making Test among depressed older adults, and to better Digit Span Backward performance among all participants. Higher levels of neuroticism were related to poorer performance on Digit Span Backward, but only among depressed older adults. Depressed participants performed more poorly on the Symbol Digit Modalities Test and the Controlled Oral Word Association Test.

CONCLUSIONS

Personality characteristics, particularly Openness to Experience, modified the relationship between depression and neuropsychological functioning among older adults. Results indicate that interventions aimed at increasing one's Openness to Experience could potentially attenuate some of the neuropsychological impairments that are associated with depression.

Neuropsychological correlates of magnetic resonance imaging-defined subcortical ischemic depression

OBJECTIVE

The goal of the current study was to examine the neuropsychological profile of magnetic resonance imaging (MRI)-defined subcortical ischemic depression (SID).

METHODS

Clinically depressed older adults with MRI-defined SID (n = 70) and depressed elders without SID (n = 75) were compared on neuropsychological performance, depression symptoms, and medical burden.

RESULTS

Group comparisons revealed that the SID was associated with worse performance on all neuropsychological measures, but also with greater age, higher cardiac illness burden, and greater deficits in the depression symptoms of self-initiation and concentration. In multivariate regression models, auditory working memory and nonverbal memory remained worse among the SID group after controlling for contributions of age, cardiovascular risk, and depression symptoms.

CONCLUSIONS

Although auditory working memory span and nonverbal memory appear to be specifically associated with the ischemic pathology that defines SID, the typical individual with SID is also likely to have a broader profile of neuropsychological deficits than those without SID because they are typically older and have specific depression symptoms that predispose them to compromised neurocognitive performance.

Pathways linking late-life depression to persistent cognitive impairment and dementia

There is a strong association between late-life depression, cognitive impairment, cerebrovascular disease, and poor cognitive outcomes, including progressive dementia, especially Alzheimer's disease. While neuroimaging evidence suggests that cerebrovascular disease plays a prominent role, it seems that depression alone may also confer substantial risk for developing Alzheimer's disease. The relationships between the prominent cerebrovascular changes, other structural abnormalities, specific forms of cognitive dysfunction, and increased risk for developing Alzheimer's disease among those with late-life depression have been difficult to reconcile. The varied findings suggest that there are likely multiple pathways to poor cognitive outcomes. We present a framework outlining multiple, non-mutually exclusive etiologic links between depression, cognitive impairment, and progressive decline, including dementia. Importantly, the model is both testable and falsifiable. Going forward, using models such as this to inform research should accelerate knowledge acquisition on the depression/dementia relationship that may be useful for dementia prevention, monitoring the impact of depression treatment on clinical status and course of illness.

The relationships of sociodemographic factors, medical, psychiatric, and substance-misuse co-morbidities to neurocognition in short-term abstinent alcohol-dependent individuals

Co-morbidities that commonly accompany those afflicted with an alcohol use disorder (AUD) may promote variability in the pattern and magnitude of neurocognitive abnormalities demonstrated. The goal of this study was to investigate the influence of several common co-morbid medical conditions (primarily hypertension and hepatitis C), psychiatric (primarily unipolar mood and anxiety disorders), and substance use (primarily psychostimulant and cannabis) disorders, and chronic cigarette smoking on the neurocognitive functioning in short-term abstinent, treatment-seeking individuals with AUD. Seventy-five alcohol-dependent participants (ALC; 51+/-9 years of age; three females) completed comprehensive neurocognitive testing after approximately 1 month of abstinence. Multivariate multiple linear regression evaluated the relationships among neurocognitive variables and medical conditions, psychiatric, and substance-use disorders, controlling for sociodemographic factors. Sixty-four percent of ALC had at least one medical, psychiatric, or substance-abuse co-morbidity (excluding smoking). Smoking status (smoker or nonsmoker) and age were significant independent predictors of cognitive efficiency, general intelligence, postural stability, processing speed, and visuospatial memory after age-normed adjustment and control for estimated pre-morbid verbal intelligence, education, alcohol consumption, and medical, psychiatric, and substance-misuse co-morbidities. Results indicated that chronic smoking accounted for a significant portion of the variance in the neurocognitive performance of this middle-aged AUD cohort. The age-related findings for ALC suggest that alcohol dependence, per se, was associated with diminished neurocognitive functioning with increasing age. The study of participants who demonstrate common co-morbidities observed in AUD is necessary to fully understand how AUD, as a clinical syndrome, affects neurocognition, brain neurobiology, and their changes with extended abstinence.

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.

Classification of white matter lesions on magnetic resonance imaging in elderly persons

White matter lesions, commonly seen on MRIs of elderly people, are related to various geriatric disorders, including cerebrovascular diseases, cardiovascular diseases, dementia, and psychiatric disorders. Currently, white matter lesions are divided into periventricular white matter lesions and deep white matter lesions. Although the meaning of these terms varies by study and this dichotomization itself is still in debate, a possible dissimilarity in pathogenic mechanisms between periventricular white matter lesions and deep white matter lesions are providing some clues for understanding pathophysiology of many geriatric syndromes associated with white matter lesions. We have reviewed the distinctions between periventricular white matter lesions and deep white matter lesions in terms of etiology, histopathology, functional correlates, and imaging methodologies. We suggest a new subclassification of white matter lesions that might have better etiological and functional relevance than the current simple dichotomization. The new categories are juxtaventricular, periventricular, deep white, and juxtacortical. This new classification scheme might contribute to reducing the heterogeneity of white matter lesion findings in future research.

Mood, cognition and in vivo protein imaging: the emerging nexus in clinical neuroscience

INTRODUCTION

Disorders of mood and cognition overlap in the elderly and there is an emerging consensus that both groups of disorders share neurobiological substrates.

METHODS

Salient peer reviewed articles focusing on late-life depression, structural neuroimaging and recent developments in positron emission tomography based in vivo protein imaging.

RESULTS

Epidemiological and clinical evidence indicates that mood and cognition in the elderly are clinically inter-related and common neurobiological mechanisms may underlie both groups of disorders. Degenerative, vascular and related mechanisms like genetically programmed abnormal protein deposition may provide the underlying neurobiological links between these disorders.

CONCLUSIONS

Modern neuroimaging approaches such as positron emission tomography (PET) based in vivo protein binding may help further elucidate common pathophysiological mechanisms and assist in the early identification of patients at risk for developing dementia over time. These developments have important mechanistic and public health significance in the elderly.

Forgetting in dementia with and without subcortical lacunes

Alzheimer's disease (AD) and subcortical ischemic vascular disease (SIVD) are common causes of dementia, often co-occur, and can present quite similarly, making differential diagnosis clinically challenging. This study tested the hypothesis that patients with SIVD retain information better than AD patients. Participants were 35 dementia patients with subcortical lacunes (SIVD group), 27 dementia patients without lacunar infarction (AD group), and 56 normal controls. Results indicated that despite comparable levels of initial acquisition, AD patients showed more rapid forgetting. Further analysis indicated that memory patterns within the SIVD group were heterogeneous, with some participants exhibiting rapid forgetting and some exhibiting good retention. SIVD participants with good retention showed a trend for greater executive impairments relative to SIVD participants with rapid forgetting and AD participants. Results suggest that rapid forgetting in SIVD may imply concomitant AD, whereas the dementia in patients with good retention may be purely vascular in origin. Three SIVD patients with rapid forgetting followed to autopsy all had AD pathology, further supporting the link between memory patterns and AD.

Executive dysfunction in subcortical ischaemic vascular disease

BACKGROUND

Executive dysfunction has been reported in patients with subcortical-frontal pathology, even in the absence of dementia.

OBJECTIVE

This study was undertaken to determine if impairments in executive functioning could be found in non-demented patients with subcortical lacunes.

METHODS

Cross sectional comparison between older control subjects (n=27) and non-demented patients with one or more subcortical lacunes (n=12). All participants were administered a neuropsychological test battery incorporating three measures of executive functioning, the Stroop interference test, California card sorting test, and the initiation-perseveration subtest of the Mattis dementia rating scale.

RESULTS

No group differences were found on measures of recent verbal memory, language, or spatial ability. Normal controls performed better than patients with lacunes in visual memory. On the Stroop interference test, patients with lacunes performed as well as controls on the colour naming condition but slower on the interference condition. Patients with lacunes also generated fewer correct sorts on the California card sort test and achieved lower scores on the initiation-perseveration subtest. Executive measures were correlated with extent of white matter signal hyperintensity but not number of lacunes.

CONCLUSION

Subcortical ischaemic vascular disease is associated with subtle declines in executive functioning and visual memory, even in non-demented patients. The pattern of cognitive impairment after subcortical lacunes is consistent with models of subcortical-frontal circuits.

The neuropsychiatry of subcortical ischemic brain disease

The subcortical regions of the brain, by virtue of their extensive connections to neocortical and limbic structures, play an important role in the regulation of neurobehavioral functions such as mood, memory, and affect. Compromise of the blood supply to the subcortex and its connections result in behavioral syndromes that often include disturbances in cognition and mood. The extent of the underlying vascular pathology and the precise circuits compromised, in general, determine the nature of the behavioral problems. The neurobiologic mechanisms responsible for these behaviors are complex and clinical management is symptomatic and largely aimed at treating the primary clinical features with appropriate pharmacologic and behavioral approaches.