Symptoms of striatofrontal dysfunction contribute to disability in geriatric depression

Late-life depression accentuates cognitive weaknesses in older adults with small vessel disease

Neuroimaging features of small vessel disease (SVD) are highly prevalent in older adulthood and associated with significant variability in clinical symptoms, yet the factors predicting these symptom disparities are poorly understood. We employed a novel metric of SVD, peak width of skeletonized mean diffusivity (PSMD), to elucidate the relationship of late-life depression (LLD) to the cognitive presentation of vascular pathology. A total of 109 older adults without a diagnosis of a neurocognitive disorder were enrolled in the study; 44 with major depressive disorder and 65 age-matched controls. Subjects completed neuropsychological testing and magnetic resonance imaging including FLAIR and diffusion tensor imaging sequences, from which white matter hyperintensity volume and diffusion metrics (fractional anisotropy, mean diffusivity, PSMD) were quantified. In hierarchical models, the relationship between vascular burden and cognitive performance varied as a function of diagnostic status, such that the negative association between PSMD and processing speed was significantly stronger in participants with LLD compared to controls. Greater PSMD also predicted poorer performance on delayed memory and executive function tasks specifically among those with LLD, while there were no associations between PSMD and task performance among controls. PSMD outperformed conventional SVD and diffusion markers in predicting cognitive performance and dysexecutive behaviors in participants with LLD. These data suggest that LLD may confer a vulnerability to the cognitive manifestations of white matter abnormalities in older adulthood. PSMD, a novel biomarker of diffuse microstructural changes in SVD, may be a more sensitive marker of subtle cognitive deficits stemming from vascular pathology in LLD.

A longitudinal study of the association between basal ganglia volumes and psychomotor symptoms in subjects with late life depression undergoing ECT

Psychomotor dysfunction (PMD) is a core element and key contributor to disability in late life depression (LLD), which responds well to electroconvulsive therapy (ECT). The neurobiology of PMD and its response to ECT are not well understood. We hypothesized that PMD in LLD is associated with lower striatal volume, and that striatal volume increase following ECT explains PMD improvement. We analyzed data from a two-center prospective cohort study of 110 LLD subjects (>55 years) receiving ECT. Brain MRI and assessment of mood, cognition, and PMD was performed 1 week before, 1 week after, and 6 months after ECT. Volumetry of the caudate nucleus, putamen, globus pallidus, and nucleus accumbens was derived from automatically segmented brain MRIs using Freesurfer®. Linear multiple regression analyses were used to study associations between basal ganglia volume and PMD. Brain MRI was available for 66 patients 1 week post ECT and in 22 patients also six months post ECT. Baseline PMD was associated with a smaller left caudate nucleus. One week after ECT, PMD improved and volume increases were detected bilaterally in the caudate nucleus and putamen, and in the right nucleus accumbens. Improved PMD after ECT did not relate to the significant volume increases in these structures, but was predicted by a nonsignificant volume change in the right globus pallidus. No volume differences were detected 6 months after ECT, compared to baseline. Although PMD is related to lower striatal volume in LLD, ECT-induced increase of striatal volume does not explain PMD improvement.

Frontal lobe function in elderly patients with Alzheimer's disease and caregiver burden

AIM

Understanding of the relationship between caregiver burden and the degree of behavioural deficits in patients with Alzheimer's disease (AD) is relatively limited. Therefore, it is worthwhile to examine the correlations between the various relevant factors to improve the efficacy of care for patients with AD. The aim of this study was to investigate the specific contributions of frontal lobe dysfunction in AD patients to caregiver burden, while controlling for other predictor variables.

METHODS

Participants included 30 pairs of caregivers and patients with AD. The Zarit Burden Interview and Frontal Assessment Battery were used to measure the caregiver burden and patients' frontal lobe function, respectively. To investigate the effects of frontal lobe dysfunction on caregiver burden, hierarchical regression equations with steps incorporating additional predictor variables were fitted. We also performed a correlation analysis between the individual subdomains of the Zarit Burden Interview and the predictor variables.

RESULTS

Our study suggests that the degree of frontal lobe dysfunction in AD patients predicts their caregiver burden, when other factors of daily functional limitations and neuropsychiatric symptoms are controlled. Daily functional limitations and neuropsychiatric symptoms affected caregivers' psychosocial burden, whereas frontal lobe dysfunction affected caregivers' burden due to the increase in the dependency of the patients.

CONCLUSION

Our findings indicate that to ameliorate the disabilities of patients and reduce caregiver burden, there is a need for interventions that focus on psychosocial burdens, as shown in previous studies, as well as on excessive dependency due to frontal lobe dysfunction.

Upright posture improves affect and fatigue in people with depressive symptoms

BACKGROUND AND OBJECTIVES

Slumped posture is a diagnostic feature of depression. While research shows upright posture improves self-esteem and mood in healthy samples, little research has investigated this in depressed samples. This study aimed to investigate whether changing posture could reduce negative affect and fatigue in people with mild to moderate depression undergoing a stressful task.

METHODS

Sixty-one community participants who screened positive for mild to moderate depression were recruited into a study purportedly on the effects of physiotherapy tape on cognitive function. They were randomized to sit with usual posture or upright posture and physiotherapy tape was applied. Participants completed the Trier Social Stress Test speech task. Changes in affect and fatigue were assessed. The words spoken by the participants during their speeches were analysed.

RESULTS

At baseline, all participants had significantly more slumped posture than normative data. The postural manipulation significantly improved posture and increased high arousal positive affect and fatigue compared to usual posture. The upright group spoke significantly more words than the usual posture group, used fewer first person singular personal pronouns, but more sadness words. Upright shoulder angle was associated with lower negative affect and lower anxiety across both groups.

LIMITATIONS

The experiment was only brief and a non-clinical sample was used.

CONCLUSIONS

This preliminary study suggests that adopting an upright posture may increase positive affect, reduce fatigue, and decrease self-focus in people with mild-to-moderate depression. Future research should investigate postural manipulations over a longer time period and in samples with clinically diagnosed depression.

The Combined Effect of Neuropsychological and Neuropathological Deficits on Instrumental Activities of Daily Living in Older Adults: a Systematic Review

To date, studies have consistently demonstrated associations between either neuropsychological deficits or neuroanatomical changes and instrumental activities of daily living (IADL) in aging. Only a limited number of studies have evaluated morphological brain changes and neuropsychological test performance concurrently in relation to IADL in this population. As a result, it remains largely unknown whether these factors independently predict functional outcome. The current systematic review intended to address this lack of information by reviewing the literature on older adults, incorporating studies that examined e.g., normal aging, but also stroke or dementia patients. A comprehensive search of databases (Pubmed, Embase, Medline, Web of Science, PsycINFO) and reference lists was performed, focusing on papers in the English language that examined the combined effect of neuropsychological and neuroanatomical factors on IADL in samples of adults with an average age above 50. In total, 58 potential articles were identified; 20 were included in the review. The results show that especially neuropsychological variables (primarily memory and executive functions) independently predict IADL. Although some unique predictive value of brain morphological changes, such as hippocampal atrophy, was found, support for the importance of white matter changes was limited. However, the results of the studies reviewed are diverse, and appear to be at least partially determined by the variables included. For example, studies were less likely to find an independent effect of cognition if they solely employed a cognitive screening instrument. This indicates that a structured examination of neuroanatomical and neuropsychological correlates of IADL in different patient populations is warranted.

Perceived and performance-based executive dysfunction in Parkinson's disease

Executive dysfunction is common in early stage Parkinson's disease (PD). We evaluated the relationship between self- and informant-report measurement of real-world executive functions as well as performance-based neuropsychological measures in mildly cognitively impaired individuals with PD and healthy controls. The PD group reported more difficulty with initiation of complex tasks compared to caregiver ratings, and processing speed was a strong predictor of self-reported executive dysfunction for the PD group, followed by depression. Processing speed and semantic verbal fluency predicted informant-reported executive dysfunction in PD. These findings highlight the contribution of speeded processing for performance of everyday executive tasks in PD.

Reduced comparison speed during visual search in late life depression

Slowed information processing is a prominent deficit in late-life depression (LLD). To better differentiate processing speed components in LLD, we examined characteristics of visual search performance in 32 LLD and 32 control participants. Data showed specific slowing in the comparison stage of visual search in LLD, rather than in encoding/response stages, but also greater overall slowing in LLD during inefficient versus efficient search. We found no group differences on traditional neuropsychological measures of processing speed. Slowed processing speed in LLD may be specific rather than general, which underscores the need to link components of processing speed to underlying neural circuitry.

Attention/processing speed prospectively predicts social impairment 18 years later in mood disorders

Cross-sectional studies suggest that cognitive deficits contribute to psychosocial impairment among individuals with mood disorders. However, studies examining whether cognition prospectively predicts psychosocial outcome are few, have used short follow-up periods, and have not demonstrated incremental validity (i.e., that cognition predicts future functioning even when controlling for baseline functioning). In a sample of 51 individuals with unipolar depression or bipolar disorder, we investigated whether attention/processing speed (APS) performance predicted social functioning 18 years later. Baseline APS predicted 18-year social functioning even after controlling for baseline social functioning and depressive symptoms, demonstrating incremental validity. Individuals with high baseline APS had stable social functioning over 18 years, whereas functioning deteriorated among those with low APS. This finding helps clarify the temporal order of cognitive and psychosocial deficits associated with mood disorders and suggests the clinical utility of cognitive measures in identifying those at risk of deterioration in social functioning.

DTI voxelwise analysis did not differentiate older depressed patients from older subjects without depression

INTRODUCTION

Neuroimaging has been widely used in studies to investigate depression in the elderly because it is a noninvasive technique, and it allows the detection of structural and functional brain alterations. Fractional anisotropy (FA) and mean diffusivity (MD) are neuroimaging indexes of the microstructural integrity of white matter, which are measured using diffusion tensor imaging (DTI). The aim of this study was to investigate differences in FA or MD in the entire brain without a previously determined region of interest (ROI) between depressed and non-depressed elderly patients.

METHOD

Brain magnetic resonance imaging scans were obtained from 47 depressed elderly patients, diagnosed according to DSM-IV criteria, and 36 healthy elderly patients as controls. Voxelwise statistical analysis of FA data was performed using tract-based spatial statistics (TBSS).

RESULTS

After controlling for age, no significant differences among FA and MD parameters were observed in the depressed elderly patients. No significant correlations were found between cognitive performance and FA or MD parameters.

CONCLUSION

There were no significant differences among FA or MD values between mildly or moderately depressed and non-depressed elderly patients when the brain was analyzed without a previously determined ROI.

Neuroplasticity-based computerized cognitive remediation for geriatric depression

OBJECTIVE

This article describes a novel treatment model designed to target specific neurocognitive deficits in geriatric depression with neuroplasticity-based computerized cognitive remediation (NBCCR).

METHOD

The recent National Institute of Mental Health (NIMH) report "From Discovery to Cure" calls for studies focusing on mechanisms of treatment response with the goal of arriving at new interventions for those who do not respond to existing treatments. We describe the process that led to the identification of specific executive deficits and their underlying neurobiology, as well as the rationale for targeting these symptoms as a part of a strategy intended to improve both executive dysfunction and depression. We then propose a strategy for further research in this emerging area.

RESULTS AND CONCLUSIONS

Despite significant developments, conventional antidepressant treatments leave many older adults still depressed and suffering. Psychotherapy may be effective in some depressed elders, although a recent review concluded that none of the available treatment studies meets stringent criteria for efficacy in the acute treatment of geriatric depression. Appropriately developed and targeted NBCCR, has the potential to serve as a novel treatment intervention for geriatric depression. Pathophysiological changes associated with executive dysfunction may be an appropriate target for NBCCR. Examining both behavioral changes and indices of structural integrity and functional change of networks related to cognitive and emotional regulation may lead to a novel treatment and elucidate the role of specific cerebral networks in geriatric depression.

Association of attentional shift and reversal learning to functional deficits in geriatric depression

OBJECTIVE

The objective of this study is to examine the association between self-reported functional disability in depressed older adults and two types of executive function processes, attentional set shifting and reversal learning.

METHODS

Participants (N = 89) were aged 60 or over and enrolled in a naturalistic treatment study of major depressive disorder. Participants provided information on self-reported function in instrumental activities of daily living (IADL) and completed the Intra-Extra Dimensional Set Shift test (IED) from the Cambridge Neuropsychological Testing Automated Battery, which assesses intra-dimensional attentional shifts, extra-dimensional attentional shifts, and reversal learning. Participants were categorized by the presence or absence of IADL difficulties and compared on IED performance using bivariable and multivariable tests.

RESULTS

Participants who reported IADL difficulties had more errors in extra-dimensional attentional shifting and reversal learning, but intra-dimensional shift errors were not associated with IADLs. Only extra-dimensional shift errors were significant in multivariable models that controlled for age, sex, and depression severity.

CONCLUSIONS

Attentional shifting across categories (i.e., extra-dimensional) was most strongly associated with increased IADL difficulties among depressed older adults, which make interventions to improve flexible problem solving a potential target for reducing instrumental disability in this population.

Genetic variation in Hyperpolarization-activated cyclic nucleotide-gated channels and its relationship with neuroticism, cognition and risk of depression

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are encoded by four genes (HCN1–4) and, through activation by cyclic AMP (cAMP), represent a point of convergence for several psychosis risk genes. On the basis of positive preliminary data, we sought to test whether genetic variation in HCN1–4 conferred risk of depression or cognitive impairment in the Generation Scotland: Scottish Family Health Study. HCN1, HCN2, HCN3, and HCN4 were genotyped for 43 haplotype-tagging SNPs and tested for association with DSM-IV depression, neuroticism, and a battery of cognitive tests assessing cognitive ability, memory, verbal fluency, and psychomotor performance. No association was found between any HCN channel gene SNP and risk of depression, neuroticism, or on any cognitive measure. The current study does not support a genetic role for HCN channels in conferring risk of depression or cognitive impairment in individuals from the Scottish population.

Regional cortical thinning in patients with major depressive disorder: a surface-based morphometry study

This study uses surfaced-based morphometry to investigate cortical thinning and its functional correlates in patients with major depressive disorder (MDD). Subjects with MDD (N=36) and healthy control subjects (N=36) were enrolled in the study. Each subject received T1 structural magnetic resonance imaging (MRI), clinical evaluations, and neuropsychological examinations of executive functions with the Color Trail Test (CTT) and the Wisconsin Card Sorting Test (WCST). This study used an automated surface-based method (FreeSurfer) to measure cortical thickness and to generate the thickness maps for each subject. Statistical comparisons were performed using a general linear model. Compared with healthy controls, subjects with MDD showed the largest area of cortical thinning in the prefrontal cortex. This study also noted smaller areas of cortical thinning in the bilateral inferior parietal cortex, left middle temporal gyrus, left entorhinal cortex, left lingual cortex, and right postcentral gyrus. Regression analysis demonstrated cortical thinning in several frontoparietal regions, predicting worse executive performance measured by CTT 2, though the patterns of cortical thickness/executive performance correlation differed in healthy controls and MDD subjects. In conclusion, the results provide further evidence for the significant role of a prefrontal structural deficit and an aberrant structural/functional relationship in patients with MDD.

Frontal function, disability and caregiver burden in elderly patients with major depressive disorder

Caregivers of patients with late-life major depressive disorder experience a significant level of general caregiver burden. Disability in patients is possibly one of the origins of caregiver burden. Frontal lobe dysfunction might be the source of disability. This study investigated if frontal lobe dysfunction (body level) of patients with late-life major depressive disorder was associated with their disability (individual level), and if it led to a high level of caregiver burden (societal level). Thirty-four unselected pairs of caregivers and their family members with late-life major depressive disorder were recruited. Frontal Assessment Battery and Timed Instrumental Activities of Daily Living (TIADL) were used to assess patients' frontal function and disability, and Caregiver Burden Inventory was used to measure caregiver burden. Frontal Assessment Battery correlated with TIADL (r= -0.47; p<0.006). TIADL score was also associated with two subscales of the Caregiver Burden Inventory: social (r = 0.38, p=0.026) and time-dependent (r= 0.37, p= 0.033). This study supported the hypothesis that frontal lobe dysfunction in elderly patients with depression is associated with their disability in instrumental activities of daily living. Disability is related to social and time-dependent aspects of caregiver burden. Further studies to examine proposed cognitive interventions are suggested to reduce patient disability and caregiver burden.

Problem-solving therapy and supportive therapy in older adults with major depression and executive dysfunction: effect on disability

CONTEXT

Older patients with depression and executive dysfunction represent a population with significant disability and a high likelihood of failing pharmacotherapy.

OBJECTIVES

To examine whether problem-solving therapy (PST) reduces disability more than does supportive therapy (ST) in older patients with depression and executive dysfunction and whether this effect is mediated by improvement in depressive symptoms.

DESIGN

Randomized controlled trial.

SETTING

Weill Cornell Medical College and University of California at San Francisco.

PARTICIPANTS

Adults (aged >59 years) with major depression and executive dysfunction recruited between December 2002 and November 2007 and followed up for 36 weeks. Intervention Twelve sessions of PST modified for older depressed adults with executive impairment or ST. Main Outcome Measure Disability as quantified using the 12-item World Health Organization Disability Assessment Schedule II.

RESULTS

Of 653 individuals referred to this study, 221 met the inclusion criteria and were randomized to receive PST or ST. Both PST and ST led to comparable improvement in disability in the first 6 weeks of treatment, but a more prominent reduction was noted in PST participants at weeks 9 and 12. The difference between PST and ST was greater in patients with greater cognitive impairment and more previous episodes. Reduction in disability paralleled reduction in depressive symptoms. The therapeutic advantage of PST over ST in reducing depression was, in part, due to greater reduction in disability by PST. Although disability increased during the 24 weeks after the end of treatment, the advantage of PST over ST was retained.

CONCLUSIONS

These results suggest that PST is more effective than ST in reducing disability in older patients with major depression and executive dysfunction, and its benefits were retained after the end of treatment. The clinical value of this finding is that PST may be a treatment alternative in an older patient population likely to be resistant to pharmacotherapy.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00052091.

Late-life depression with comorbid cognitive impairment and disability: nonpharmacological interventions

Less than half of older adults with depression achieve remission with antidepressant medications, and rates of remission are even poorer for those with comorbid conditions. Psychosocial interventions have been effective in treating geriatric depression, either alone or better yet, in combination with antidepressant medications. Traditional strategies for nonpharmacological treatment of late-life depression do not specifically address the co-occurring cognitive impairment and disability that is prevalent in this population. Newer therapies are recognizing the need to simultaneously direct treatment efforts in late-life depression towards the triad of depressive symptoms, cognitive dysfunction, and functional disability that is so often found in geriatric depression, and this comprehensive approach holds promise for improved treatment outcomes.

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.

[Depression and frontal dysfunction: risks for the elderly?]

BACKGROUND

Frontal lobe syndromes include reduced activity, particularly a diminution of spontaneous activity, lack of drive, inability to plan ahead, and induce a lack of concern. These last points constitute the executive dysfunction syndrome. That executive dysfunction could be the core defect in patients with geriatric or vascular depression, and might be related to frontal-subcortical circuit dysfunction. Sometimes frontal lobe syndromes are associated with restless, aimless, uncoordinated behavior or even disinhibition, increasing the risks of falls and of malnutrition. Some authors have distinguished between lesions of the lateral frontal cortex, most closely linked to the motor structures of the brain, which lead to disturbances of movement and action with perseveration and inertia, and lesions of the orbital and medial areas, interlinked with limbic and reticular systems, damage to which leads to disinhibition and changes of affect. The medial frontal syndrome is marked by akinesia, associated with gait disturbances, and loss of autonomy. For these reasons, it has been proposed that a subtype of depression, "depression-executive dysfunction syndrome" could occur in late life. This assertion was based on clinical, neuropathological, and neuroimaging findings suggesting that frontostriatal dysfunctions contribute to the development of both depression and executive dysfunction and influence the course of depression. Depressive symptomatology, and especially psychomotor retardation and loss of interest in activities, contributed to disability in depression-executive dysfunction syndrome patients. This study is not restricted to major depression. It examined the relationship of executive impairment to the course of depressive symptoms among a psychogeriatric population with dementia or depression in order to assess the consequences of these pathologies on disabilities of aged persons.

METHODS

The study was carried out in Limoges (France) during 2006 and 2007. Three hundred and twenty one psychogeriatric outpatients were included after their written agreement. They were assessed using different scales for autonomy, cognition, depression, frontal impairment and these results were compared with the risk of fall, a possible loss of autonomy and a proteino-energical malnutrition. The statistical study was made using the Systat 11 software. The following tests were used: Student Test, Chi(2) test, and the Manova test, which was adjusted to the duration of the disease, the caregiver's age, his/her education level, and level of cognitive impairment. The regression method used was the multiple linear regression method as well as a descending step-by-step analysis.

RESULTS

One hundred and thirty six males (77.3+/-7.09 years old) and 185 females (80.4+/-6.5 years old) were recruited. Patients mainly presented with Alzheimer's disease (n=123) and 65 presented an associated depression, 25 presented vascular dementia, 30 a Lewy bodies dementia, 27 a fronto-temporal dementia. Twenty-seven presented psychosis and 40 a Mild Cognitive Impairment. A control group was composed of 33 persons presumed without psychogeriatric pathologies. Depression associated with an executive dysfunction syndrome increased loss of autonomy, the risk of fall and of malnutrition, especially in the case of cognitive impairment. The multivariate regression analysis step-by-step shows an increasing risk of fall in the presence of a depression-executive dysfunction syndrome. Motivation is altered when the patient is depressed. In demented patients, depression significantly increases behavioral disorders, social and familial relationships, and instrumental acts of daily life. It precipitates the risks of falls and of malnutrition.

DISCUSSION

The principal finding of this study is that geriatric depression is characterized by impaired executive functioning. In the present study, depressed patients also had a greater tendency to fall and to suffer from malnutrition. Executive processes are fundamental to the daily functioning of depressed older adults, and dysfunction may lead to a lack of compensatory strategies that would improve the outcomes of late-life depression or of increasing dependency as well. In demented patients, depression triggers loss of motivation and executive dysfunction as well.

CONCLUSIONS

Depression and executive dysfunction triggers the loss of autonomy, the risk of fall and of malnutrition in elderly patients. The clinical significance of this study is that the delineation of specific executive in depressed elderly patients may facilitate the development of effective treatment interventions, including treatment for geriatric depression.

Depression, disability and intermediate pathways: a review of longitudinal studies in elders

Cross-sectional studies demonstrate depression is associated with disability in elders. These studies also report that disability in depressed elders is associated with greater medical illness burden, cognitive impairment, and behavioral changes. Only longitudinal studies, however, can determine the impact of depression and its comorbidities on functional decline. This review summarizes the findings of 20 longitudinal studies examining the relationship between baseline or incident depression and functional decline. However, the mediational effects of potential risk factors identified by cross-sectional studies cannot be derived from the current literature. We propose a mediational effects model for future longitudinal studies, incorporating measures sensitive to both mood symptoms and the medical, cognitive, and behavioral comorbidities of depression to better understand the impact of each on functional decline and to focus future clinical interventions.

Psychomotor symptoms in depression: a diagnostic, pathophysiological and therapeutic tool

BACKGROUND

Psychomotor disturbances have been described repeatedly over many centuries. More recently, Sobin and Sackeim [Sobin, C., Sackeim, H.A., 1997. Psychomotor symptoms of depression. Am. J. Psychiatry. 154, 4-17.] discussed the relevance of psychomotor symptoms in depression in an extensive review. Since their report, new pathophysiological, diagnostic and therapeutic findings have been published. In the current review of the recent literature, we aim to argue the importance of psychomotor symptoms in depression and propose directions for future research.

METHOD

A review of all the relevant reports on this topic, published between 1996 and 2006, was conducted.

RESULTS

Several assessment methods demonstrate the diagnostic and pathophysiological significance of psychomotor symptoms. Antidepressants show differential effects on psychomotor performance and findings concerning the symptoms' predictive capacity for clinical response are contradictory. Numerous imaging studies as well as studies on the neurotransmitter systems and the HPA-axis contribute to the elucidation of the neurobiological processes underlying impaired psychomotor functioning in depression.

CONCLUSIONS

Psychomotor disturbances are of great diagnostic significance for the depressive subtype of melancholia. To enhance the conceptualisation of the construct 'psychomotor' a standardised battery for their assessment is recommended. As to the symptoms' predictive therapeutic power, to date research into functional outcome and studies applying objective experimental assessment methods are lacking. Moreover, the reported pathophysiological importance of dopamine for 'retarded depression' still warrants translation to the daily practice.

Anterior cingulate dysfunction in geriatric depression

BACKGROUND

Although several brain abnormalities have been identified in geriatric depression, their relationship to the pathophysiological mechanisms leading to the development and perpetuation of this syndrome remain unclear.

METHODS

This paper reviews findings on the anterior cingulate cortex (ACC) function and on the relationship of ACC abnormalities to the clinical presentation and the course of geriatric depression in order to elucidate the pathophysiological role of ACC in this disorder.

RESULTS

The ACC is responsible for conflict detection and emotional evaluation of error and is connected to brain structures that regulate mood, emotional valence of thought and autonomic and visceral responses, which are functions disturbed in depression. Geriatric depression often is accompanied by abnormalities in some executive functions and has a clinical presentation consistent with ACC abnormalities. Indices of ACC dysfunction are associated with adverse outcomes of geriatric depression.

CONCLUSIONS

Converging findings suggest that at least some ACC functions are abnormal in depression and these abnormalities are pathophysiologically meaningful. Indices of ACC dysfunction may be used to identify subgroups of depressed elderly patients with distinct illness course and treatment needs and serve as the theoretical background for novel treatment development.

Executive dysfunction in major depressive disorder

Executive dysfunction is commonly seen in major depression. The types of executive deficits seen in depression include problems with planning, initiating and completing goal-directed activities. Executive dysfunction may vary as a function of the severity of depression. In addition, a subset of geriatric depression is also characterized by prominent deficits in executive functioning. The presence of executive dysfunction in depression is associated with vocational disability and possibly poorer treatment response. While few studies have examined the treatment of executive dysfunction in depression, preliminary work suggests that both pharmacologic interventions and psychosocial interventions such as problem solving therapy may be efficacious.

Cerebrovascular disease and late-life depression

Depression may occur as a result of vascular disease in a significant subpopulation of elderly persons. Indirect support for vascular disease as an underlying etiology of late-life depression includes the high rate of depression in patients with vascular disease, the frequency of "silent stroke" and white-matter hyperintensities in late-life depression, and the lower frequency of positive family histories of depression in such patients. The authors evaluate the associations of late-life depression with cerebrovascular disease by reviewing the existing pathophysiological, prognosis, and treatment-outcomes studies. Findings are based on review of the current literature systematically searched in electronic databases. Review of such studies indicates a high frequency of depression in older patients with cardiovascular and cerebrovascular diseases, and the possibility of a bidirectional relationship between depression and vascular disease. Studies examining patients with vascular depression have found that such patients have different symptom profiles, greater disability, and higher risk for poorer outcomes than those with nonvascular depression. Since the vascular depression hypothesis was proposed as a conceptual framework, evidence has accumulated that patients with vascular depression may have poorer outcomes that may be related in part to executive dysfunction and consequent disability. However, the association of vascular risk factors with geriatric depression has not been consistent in the studies to-date. Although an association between a subset of late-life depression and vascular disease is clear, significant gaps remain in our understanding. Further research is needed to establish the precise linkages and interactions between vascular disease and geriatric depression.

Differential patterns of psychomotor functioning in unmedicated melancholic and nonmelancholic depressed patients

Few studies examining psychomotor retardation (PR) in patients with major depressive disorder (MDD) included medication-free patients. The purpose of this study was (1) to examine whether unmedicated patients with MDD would exhibit PR, (2) to determine whether this retardation, if present, was more cognitive or motor in nature, and (3) to investigate whether any differences in PR could be established between melancholic and nonmelancholic depressed patients. Thirty-eight unmedicated inpatients with severe MDD (20 melancholic and 18 nonmelancholic patients) and 38 matched controls were compared on figure-copying tasks in which the cognitive task difficulty was manipulated. In addition, a simple motor task and the symbol digit substitution task (SDST) were administered. As a group, the patients were significantly slower performing all tasks and both initiation times (IT) and movement times (MT) were prolonged. However, when a distinction was made between the two subtypes, only the melancholic patients showed prolonged MTs compared to the controls. Furthermore, the melancholic patients differed significantly from the controls in IT in all tasks. The nonmelancholic patients had significantly longer ITs than the controls in two copying tasks. It can be concluded that there was clear cognitive and motor slowing in this group of unmedicated inpatients with MDD. The melancholic patients were more severely affected than the nonmelancholic patients and showed a slowing of cognitive as well as motor processes. Differences in psychomotor functioning between melancholic and nonmelancholic depressed patients could imply different underlying neurobiological disturbances in these subtypes of major depression.

Clinical characteristics of magnetic resonance imaging-defined subcortical ischemic depression

BACKGROUND

There is a substantial body of research supporting the vascular depression hypothesis of late-life depression. To update this hypothesis so it incorporates recent research, we propose that the term subcortical ischemic vascular depression may be a more accurate representation of the disease process. We sought to investigate this diagnosis as a construct by examining differences between depressed subjects with and without magnetic resonance imaging defined subcortical ischemic vascular depression.

METHODS

This case-control study examined 139 depressed elderly subjects. Demographic data, psychiatric, medical, and family history, depressive symptomatology, and functional impairment were compared between groups dichotomized based on neuroimaging findings.

RESULTS

Seventy-five (54%) of the subjects met neuroimaging criteria for subcortical ischemic vascular depression. Age was most strongly associated with increased prevalence of subcortical ischemic vascular depression. Lassitude and a history of hypertension were also positively associated with the diagnosis; a family history of mental illness and loss of libido were negatively associated with the diagnosis.

CONCLUSIONS

These data support that subcortical ischemic vascular depression may be a specific syndrome from other types of late-life depression. Further research is needed to further characterize this disorder, particularly in regards to cognitive function and treatment implications.

Apathy and executive function in depressed elderly

Apathy and executive cognitive dysfunction (ECD) are important though conceptually different aspects of late-life depression. The primary objective of this study was to evaluate the relationship of apathy to ECD. The authors also evaluated the relationship of apathy and ECD to global cognitive impairment and word generation. Fifty-two elderly subjects with major depression and MMSE scores of 15 or greater were evaluated with apathy-related items from the Hamilton rating scale for depression (ApHRSD), the Executive Interview (EXIT), the Dementia Rating Scale (DRS), and the Controlled Oral Word Association test (COWA). ApHRSD scores were not significantly correlated with any of these variables. EXIT scores were correlated significantly with DRS and COWA. The results suggest that apathy and ECD may be independent of each other in some samples of elderly with late-life depression. Correlations may have been reduced by low variance for the variables of interest and by psychometric limitations of the ApHRSD.

Medical burden, cerebrovascular disease, and cognitive impairment in geriatric depression: modeling the relationships with the CART analysis

Herein, the background information reflecting roles of medical burden, cerebrovascular disease and risk factors, and cognitive impairment in geriatric depression are reviewed. The authors then propose a nonparametric statistical approach to the data analysis of multiple putative causal variables for late-life depression, the Classification and Regression Tree Analysis. This analysis presents a useful approach to modeling nonlinear relationships and interactions among variables measuring physical and mental health, as well as magnetic resonance imaging and cognitive measures in depressed elderly. This method uncovers the existing interactions among multiple predictor variables, and provide thresholds for each variable, at which its predictive power becomes statistically significant. It presents a "hierarchy" of the predictors in a form of a decision tree by finding the best combination of predictors of an outcome. The authors present two models based on demographic variables, measures of vascular and nonvascular medical burden, neuroimaging indices, the Mini-Mental State Examination score, and neuropsychological test scores of 81 elderly depressed subjects. Cognitive tests of verbal fluency and executive function are identified as the best predictors of depression, followed by the frontal lobe volume and Mini-Mental State Examination. The authors observed that an interaction between frontal lobe volume, total lesion volume, and medical burden was predictive of depression.

Comorbidity of late life depression: an opportunity for research on mechanisms and treatment

Late life depression principally affects individuals with other medical and psychosocial problems, including cognitive dysfunction, disability, medical illnesses, and social isolation. The clinical associations of late life depression have guided the development of hypotheses on mechanisms predisposing, initiating, and perpetuating specific mood syndromes. Comorbidity studies have demonstrated a relationship between frontostriatal impairment and late life depression. Further research has the potential to identify dysfunctions of specific frontostriatal systems critical for antidepressant response and to lead to novel pharmacological treatments and targeted psychosocial interventions. The reciprocal interactions of depression with disability, medical illnesses, treatment adherence, and other psychosocial factors complicate the care of depressed older adults. Growing knowledge of the clinical complexity introduced by the comorbidity of late life depression can guide the development of comprehensive treatment models. Targeting the interacting clinical characteristics associated with poor outcomes has the potential to interrupt the spiral of deterioration of depressed elderly patients. Treatment models can be most effective if they focus on amelioration of depressive symptoms, but also on treatment adherence, prevention of relapse and recurrence, reduction of medical burden and disability, and improvement of the quality of life of patients and their families.

Standard measures of executive function in predicting instrumental activities of daily living in older adults

OBJECTIVE

The purpose of this study was to examine the ability of specific, commonly used neuropsychological tests of executive function to predict functional status among a group of elderly subjects.

METHODS

Fifty study participants underwent a brief neuropsychological evaluation of executive functions and assessment of instrumental activities of daily living (IADL).

RESULTS

A multiple stepwise regression analysis indicated that executive function tests accounted for 54% of the variance in functional status. An examination of the standardized regression coefficients revealed that Trail Making Test-Part B and the Wisconsin Card Sorting Test were the only two of the five executive function tests that significantly predicted functional status. These executive function measures contributed significantly to the prediction of functional status even after statistically controlling for age, sex, and education.

CONCLUSION

Thus, the common clinical measures of executive function are useful in predicting functional status in older adults.

Subcortical white matter lesions and functional impairment in geriatric depression

Geriatric depression is associated with significant functional impairment. There is also growing evidence linking vascular brain changes to depression in late life. We sought to examine the relationship between cerebrovascular disease and impairment in basic activities of daily living (BADL) and instrumental activities of daily living (IADL) in a group of older depressives. The sample consisted of 224 depressed adults aged 60 years and above enrolled in Duke's Mental Health Clinical Research Center. All subjects had unipolar major depression and were free of other major psychiatric and neurological illness, including dementia. In a structured interview, subjects reported their medical history and ability to perform both BADL and IADL. Geriatric psychiatrists assessed cognition using the Mini Mental State Examination (MMSE) and depression severity using the Montgomery Asberg Depression Rating Scale (MADRS). Subjects had a standardized magnetic resonance imaging (MRI) brain scan. MRI scans were processed using a semi-automated method to determine volumes of subcortical white matter lesions (WML) and subcortical gray matter lesions (GML). Logistic regression was used to examine effects of WML and GML controlling for demographic and clinical factors. Greater volume of WML was associated with impairment in both BADL and IADL, while GML was associated with IADL impairment. In logistic models, WML remained significantly associated with IADL after controlling for the effects of age, gender, depression severity, and medical comorbidity. We concluded that white matter lesions are independently associated with functional impairment. Further studies are needed to understand how these lesions affect function, e.g., through effects on cognition or motor skills.

Clinical presentation of the "depression-executive dysfunction syndrome" of late life

It has been proposed that a "depression-executive dysfunction (DED) syndrome" occurs in late life. This assertion was based on clinical, neuropathological, and neuroimaging findings suggesting that frontostriatal dysfunctions contribute to the development of both depression and executive dysfunction and influence the course of depression. The authors describe the clinical presentation of DED and its relationship to disability, studying 126 elderly subjects with major depression and evaluating depressive symptoms, cognitive functioning, disability, and personality dimensions. Patients with the DED syndrome had reduced fluency, impaired visual naming, paranoia, loss of interest in activities, and psychomotor retardation, but showed a rather mild vegetative syndrome. Depressive symptomatology, and especially psychomotor retardation and loss of interest in activities, contributed to disability in DED patients, whereas paranoia was associated with disability independently of executive dysfunction. These findings may aid clinicians in identifying patients needing vigilant follow-up, because depression with executive dysfunction was found to be associated with disability, poor treatment response, relapse, and recurrence.