Antidepressant treatment and worsening white matter on serial cranial magnetic resonance imaging in the elderly: the Cardiovascular Health Study

White matter diffusivity and its correlations to state measures of psychopathology in male refugees with posttraumatic stress disorder

Post-traumatic stress disorder (PTSD) is a heterogenous condition and the underlying neurobiology is still poorly understood. In this study, we tested the hypothesis that PTSD is associated with microstructural changes in white matter (WM) fibre tracts that connect regions involved in emotional processing, memory, attention, and language. Furthermore, we examined how different response patterns to individualized trauma-provoking stimuli related to underlying WM microstructure. Sixty-nine trauma-affected male refugees with PTSD (N = 38) or without PTSD (N = 31) underwent clinical assessments and diffusion-weighted magnetic resonance imaging (DWI) of the whole brain at 3 Tesla. Diffusion tensor metrics were computed from DWI data and used to characterize regional white-matter microstructure. An automated tract segmentation method was used to extract diffusion tensor metrics from subject-based reconstructions of tract segments (ROI), including uncinate fasciculus (UF), cingulum bundle (CB), superior longitudinal fasciculus (SLF) in three subdivisions (SLF I - III), and fibre bundles connecting orbito-frontal cortex to striatum (OF-ST). Outside the scanner we obtained measures of immediate (state) arousal, avoidance and dissociation symptoms assessed in response to auditory exposure to a personal traumatic memory. Using mean FA of the middle part of each ROI, mixed ANOVA revealed a significant interaction between group, ROI and hemisphere. Post-hoc comparisons showed that, relative to refugees without PTSD, refugees with PTSD had lower FA in right CB, left SLF-I, bilateral OF-ST and bilateral SLF-II. Mean FA scaled negatively with avoidance in right CB while mean FA in bilateral UF scaled positively with individual scores reflecting dissociation symptoms. The results support a pathophysiological model of PTSD that implicates limbic structures, prefrontal cortex and striatum. The results also emphasize the need to consider PTSD's multifaceted manifestations when searching for functional-structural relationships.

White matter microstructural differences across major depressive disorder, bipolar disorder and schizophrenia: A tract-based spatial statistics study

BACKGROUND

White matter abnormalities have been implicated in mental disorders including major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia (SZ); however, the shared and distinct white matter integrity across mental disorders is still unclear.

METHODS

A total of 290 participants (MDD = 85, BD = 42, SZ = 68, and healthy controls = 95) were included in the present study. Tract-based spatial statistics were performed to measure fractional anisotropy (FA) and characterize shared and distinguishing white matter changes across mental disorders.

RESULTS

We found that decreased FA converged across MDD, BD and SZ in the body and genu of the corpus callosum, bilateral anterior and posterior corona radiata, and right superior corona radiata. By contrast, diagnosis-specific effect was only found in MDD in the anterior portion of anterior corona radiata.

LIMITATIONS

The small and imbalanced sample size, and possible confounding effects of medication.

CONCLUSIONS

Our findings suggest that abnormally reduced white matter integrity in the interhemispheric and thalamocortical circuit could be consistently involved in the pathogenesis of MDD, BD and SZ.

Association Between Cerebral Small Vessel Disease With Antidepressant Use and Depression: 3C Dijon Magnetic Resonance Imaging Study

Background and Purpose- Evidence links antidepressant use with cerebral small vessel disease; however, it remains unclear whether people with depression face comparable risk. This study aims to determine the association between antidepressant drug use and depression with markers of cerebral small vessel disease. Methods- One thousand nine hundred five participants (mean age, 72.5 years; 60% women) without stroke or dementia history underwent brain magnetic resonance imaging at baseline, and 1402 individuals underwent a second magnetic resonance imaging at 4 years. Outcomes were lacunes 3 to 15 mm and white matter hyperintensity volume (cm³) at baseline and follow-up. Exposure to antidepressants was grouped as (1) selective serotonin reuptake inhibitors (n=68), (2) tricyclics (n=40), (3) atypicals (n=24), (4) depressed nonusers (n=303), and (5) nondepressed/nonuser group (reference group, n=1470). Statistical analyses adjusted for propensity scores due to the nonrandomized exposure to antidepressant drugs. Results- There was an association between use of atypical antidepressants with lacunes at baseline (adjusted rate ratio, 2.59 [95% CI, 1.14-5.88]; P=0.023) and follow-up (adjusted rate ratio, 3.05 [95% CI, 1.25-7.43]; P=0.014). Lacunes at baseline were also associated with depressed nonusers (adjusted rate ratio, 1.53 [95% CI, 1.06-2.21]; P=0.023). Selective serotonin reuptake inhibitor users and depressed nonusers displayed higher total, periventricular, and deep white matter hyperintensity volumes at baseline. Selective serotonin reuptake inhibitor users had higher deep white matter hyperintensity volumes at follow-up. Conclusions- Users of atypical antidepressants, selective serotonin reuptake inhibitors, and depressed people without any antidepressant exposure all displayed markers of cerebral small vessel disease higher than the nondepressed/nonuser group. The findings suggest that cerebral small vessel disease is associated with depression and exposure to antidepressants.

Oxygenation differs among white matter hyperintensities, intersected fiber tracts and unaffected white matter

White matter hyperintensities of presumed vascular origin are frequently observed on magnetic resonance imaging in normal aging. They are typically found in cerebral small vessel disease and suspected culprits in the etiology of complex age- and small vessel disease-related conditions, such as late-onset depression. White matter hyperintensities may interfere with surrounding white matter metabolic demands by disrupting fiber tract integrity. Meanwhile, risk factors for small vessel disease are thought to reduce tissue oxygenation, not only by reducing regional blood supply, but also by impairing capillary function. To address white matter oxygen supply–demand balance, we estimated voxel-wise capillary density as an index of resting white matter metabolism, and combined estimates of blood supply and capillary function to calculate white matter oxygen availability. We conducted a cross-sectional study with structural, perfusion- and diffusion-weighted magnetic resonance imaging in 21 patients with late-onset depression and 21 controls. We outlined white matter hyperintensities and used tractography to identify the tracts they intersect. Perfusion data comprised cerebral blood flow, blood volume, mean transit time and relative transit time heterogeneity—the latter a marker of capillary dysfunction. Based on these, white matter oxygenation was calculated as the steady state cerebral metabolic rate of oxygen under the assumption of normal tissue oxygen tension and vice versa. The number, volume and perfusion characteristics of white matter hyperintensities did not differ significantly between groups. Hemodynamic data showed white matter hyperintensities to have lower blood flow and blood volume, but higher relative transit time heterogeneity, than normal-appearing white matter, resulting in either reduced capillary metabolic rate of oxygen or oxygen tension. Intersected tracts showed significantly lower blood flow, blood volume and capillary metabolic rate of oxygen than normal-appearing white matter. Across groups, lower lesion oxygen tension was associated with higher lesion number and volume. Compared with normal-appearing white matter, tissue oxygenation is significantly reduced in white matter hyperintensities as well as the fiber tracts they intersect, independent of parallel late-onset depression. In white matter hyperintensities, reduced microvascular blood volume and concomitant capillary dysfunction indicate a severe oxygen supply–demand imbalance with hypoxic tissue injury. In intersected fiber tracts, parallel reductions in oxygenation and microvascular blood volume are consistent with adaptations to reduced metabolic demands. We speculate, that aging and vascular risk factors impair white matter hyperintensity perfusion and capillary function to create hypoxic tissue injury, which in turn affect the function and metabolic demands of the white matter tracts they disrupt.

White matter integrity in schizophrenia and bipolar disorder: Tract- and voxel-based analyses of diffusion data from the Connectom scanner

Background

Diffusion imaging abnormalities have been associated with schizophrenia (SZ) and bipolar disorder (BD), indicating impaired structural connectivity. Newer methods permit the automated reconstruction of major white matter tracts from diffusion-weighted MR images in each individual's native space. Using high-definition diffusion data from SZ and BP subjects, we investigated brain white matter integrity using both an automated tract-based and voxel-based methods.

Methods

Using a protocol matched to the NIH (Young-Adult) Human Connectome Project (and collected on the same customized ‘Connectom’ scanner), diffusion scans were acquired from 87 total participants (aged 18–30), grouped as SZ (n = 24), BD (n = 33) and healthy controls (n = 30). Fractional anisotropy (FA) of eighteen white matter tracks were analyzed using the TRACULA software. Voxel-wise statistical analyses of diffusion data was carried out using the tract-based spatial statistics (TBSS) software. TRACULA group effects and clinical correlations were investigated using analyses of variance and multiple regression.

Results

TRACULA analysis identified a trend towards lower tract FA in SZ patients, most significantly in the left anterior thalamic radiation (ATR; p = .04). TBSS results showed significantly lower FA voxels bilaterally within the cerebellum and unilaterally within the left ATR, posterior thalamic radiation, corticospinal tract, and superior longitudinal fasciculus in SZ patients compared to controls (FDR corrected p < .05). FA in BD patients did not significantly differ from controls using either TRACULA or TBSS. Multiple regression showed FA of the ATR as predicting chronic mania (p = .0005) and the cingulum-angular bundle as predicting recent mania (p = .02) in patients. TBSS showed chronic mania correlating with FA voxels within the left ATR and corpus callosum.

Conclusions

White matter abnormality in SZ varies in severity across different white matter tract regions. Our results indicate that voxel-based analysis of diffusion data is more sensitive than tract-based analysis in identifying such abnormalities. Absence of white matter abnormality in BD may be related to medication effects and age.

•

Our study investigated white matter integrity in 87 young schizophrenia, bipolar disorder and control subjects with a tract-based (TRACULA) and a voxel-based (TBSS) approach, using high-definition diffusion imaging data obtained from the Human Connectome Project ‘Connectom’ scanner.

•

TRACULA evaluated fractional anisotropy (FA) from 18 white matter tracts. TBSS evaluated regional white matter FA.

•

TRACULA identified a trend towards lower tract FA in schizophrenia subjects across multiple tracts. TBSS results showed mainly unilaterally decreased FA voxels in schizophrenia subjects. FA in bipolar patients did not significantly differ from controls with either method.

•

With TRACULA, multiple regression showed that anterior thalamic radiation FA predicted chronic affectivity and cingulum-angular bundle FA predicted recent mania in patients. With TBSS, chronic mania correlated with FA voxels within the left anterior thalamic radiation and corpus callosum.

Increased Risk of Dementia in Patients with Antidepressants: A Meta-Analysis of Observational Studies

Antidepressants are the most commonly and widely used medication for its effectiveness in the treatment of anxiety and depression. A few epidemiological studies have documented that antidepressant is associated with increased risk of dementia so far. Here, our aim is to assess the association between antidepressant use and risk of dementia in elderly patients. We searched articles through MEDLINE, EMBASE, Google, and Google Scholar from inception to December 1, 2017, that reported on the association between antidepressant use and dementia risk. Data were collected from each study independently, and study duplication was checked by at least three senior researchers based on a standardized protocol. Summary relative risk (RR) with 95% CI was calculated by using a random-effects model. We selected 9 out of 754 unique abstracts for full-text review using our predetermined selection criteria, and 5 out of these 9 studies, comprising 53,955 participants, met all of our inclusion criteria. The overall pooled RR of dementia was 1.75 (95% CI: 1.033–2.964) for SSRIs whereas the overall pooled RR of dementia was 2.131 (95% CI: 1.427–3.184) for tricyclic use. Also, MAOIs showed a high rate of increase with significant heterogeneity. Our findings indicate that antidepressant use is significantly associated with an increased risk of developing dementia. Therefore, we suggest physicians to carefully prescribe antidepressants, especially in elder patients. Additionally, treatment should be stopped if any symptoms related to dementia are to be noticed.

White Matter Hyperintensity Accumulation During Treatment of Late-Life Depression

White matter hyperintensities (WMHs) have been shown to be associated with the development of late-life depression (LLD) and eventual treatment outcomes. This study sought to investigate longitudinal WMH changes in patients with LLD during a 12-week antidepressant treatment course. Forty-seven depressed elderly patients were included in this analysis. All depressed subjects started pharmacological treatment for depression shortly after a baseline magnetic resonance imaging (MRI) scan. At 12 weeks, patients underwent a follow-up MRI scan, and were categorized as either treatment remitters (n=23) or non-remitters (n=24). Among all patients, there was as a significant increase in WMHs over 12 weeks (t(46)=2.36, P=0.02). When patients were stratified by remission status, non-remitters demonstrated a significant increase in WMHs (t(23)=2.17, P=0.04), but this was not observed in remitters (t(22)=1.09, P=0.29). Other markers of brain integrity were also investigated including whole brain gray matter volume, hippocampal volume, and fractional anisotropy. No significant differences were observed in any of these markers during treatment, including when patients were stratified based on remission status. These results add to existing literature showing the association between WMH accumulation and LLD treatment outcomes. Moreover, this is the first study to demonstrate similar findings over a short interval (ie 12 weeks), which corresponds to the typical length of an antidepressant trial. These findings serve to highlight the acute interplay of cerebrovascular ischemic disease and LLD.

Childhood adversity, depression, age and gender effects on white matter microstructure: a DTI study

Previous diffusion tensor imaging (DTI) studies have shown that various factors can affect white matter (WM) tract diffusivity. The aim of the present study was to investigate the effects of childhood adversity (CA), age and gender on WM diffusivity in tracts that are thought to be involved in emotional regulation in individuals with major depressive disorder (MDD) and healthy controls (HC). DTI was obtained from 46 subjects with MDD and 46 HC subjects. Data were pre-processed and deterministic tractography was applied in the cingulum, uncinate fasciculus (UF), fornix, superior longitudinal fasciculus (SLF) and fronto-occipital fasciculus (FOF). In subjects with a history of CA, fractional anisotropy (FA) was greater in the rostral cingulum (RC) and dorsal cingulum, whereas radial diffusivity (RD) was smaller in the RC when compared with subjects with no history of CA. In the UF, FOF and parahippocampal cingulum, FA was greater in the left hemisphere in the subjects with CA when compared with those without CA. Age affected FA, longitudinal diffusivity and RD in the UF, fornix, FOF and SLF, reflecting axonal and myelin degeneration with increasing age. Depression or gender did not have any effects on the diffusivity measures. Due to the cross-sectional nature of the study, a recall bias for CA and possible effects of medical treatment on diffusivity measures could have played a role. CA and age could increase the likelihood to develop WM microstructural anomalies in the brain affective network. Moreover, subjects with CA could be more vulnerable to FA changes.

Cortical changes associated with depression and antidepressant use in Alzheimer and Lewy body dementia: an MRI surface-based morphometric study

CONTEXT

Depression is common in dementia, especially in the early stages, with important clinical implications, but the etiology is unknown and most likely heterogeneous. Antidepressant use in the elderly without dementia has previously been shown to be associated with high risks of adverse events and with structural brain alterations.

OBJECTIVE

To investigate cortical changes associated with depression and antidepressant use in patients with mild Alzheimer's disease (AD) and Lewy body dementia (LBD).

METHODS

74 subjects with mild AD and LBD from geriatric and psychiatry outpatient clinics in Western Norway were included. The Montgomery-Asberg Depression Rating Scale (MADRS) was used to assess depression. Automatic preprocessing using Freesurfer included steps for white and grey matter surface reconstruction. The resulting cortical thickness was analyzed using linear modeling.

RESULTS

Clusters of depression-associated thinning were found in prefrontal and temporal areas. Treatment-associated thinning was observed in the parahippocampal region and was significant even after correction for age, sex, AD/LBD diagnosis, and MADRS scores.

CONCLUSION

Depression in mild AD and LBD is associated with cortical thinning in prefrontal and temporal areas. The findings suggest that depressive symptoms in mild dementia could develop due to neurodegeneration in the same neural circuits that are critical for depression across different brain disorders. Antidepressant use in patients with mild AD and LBD is associated with parahippocampal thinning. Taken together with low efficacy of antidepressants in cognitively impaired patients and high risks of adverse events, our results suggest a need to re-evaluate the treatment approaches for depression and the role of antidepressants in patients with dementia.

Widespread changes of white matter microstructure in obsessive-compulsive disorder: effect of drug status

Diffusion tensor imaging (DTI) allows the study of white matter (WM) structure. Literature suggests that WM structure could be altered in obsessive-compulsive disorder (OCD) proportional to the severity of the disease. Heterogeneity of brain imaging methods, of the studied samples, and of drug treatments make localization, nature, and severity of the WM abnormalities unclear. We applied Tract-Based Spatial Statistics (TBSS) of DTI measures to compare fractional anisotropy (FA), mean, axial, and radial diffusivity of the WM skeleton in a group of 40 consecutively admitted inpatients affected by severe OCD (18 drug-naive, and 22 with an ongoing drug treatment) and 41 unrelated healthy volunteers from the general population. Data were analyzed accounting for the effects of multiple comparisons, and of age, sex, and education as nuisance covariates. Compared to controls, OCD patients showed a widespread reduction of FA with a concurrent increase of mean and radial diffusivity. In no brain areas patients had higher FA or lower diffusivity values than controls. These differences were observed in drug-treated patients compared to drug-naive patients and healthy controls, which in turn did not differ among themselves in any DTI measure. Reduced FA with increased mean and radial diffusivity suggests significant changes in myelination of WM tracts, without axonal loss. Drug treatments could modify the structure of cell membranes and myelin sheaths by influencing cellular lipogenesis, cholesterol homeostasis, autophagy, oligodendrocyte differentiation and remyelination. Changes of DTI measures in drug-treated OCD patients could reflect pathophysiological underpinnings of OCD, or a yet unexplored part of the mechanism of action of drugs.

Antidepressant use is related to larger white matter lesion volume in patients with symptomatic atherosclerotic disease: the SMART-MR study

Although a relation between depression and white matter lesions (WML) is frequently observed, the direction of causation remains unknown. We investigated whether depressed mood was associated with baseline severity and change in WML volume during 4 years of follow-up, and the relative contribution of mood symptoms and antidepressant use to this relation. Within the SMART-MR study 594 patients (58 ± 10 years) with symptomatic atherosclerotic disease had assessments of mood symptoms and antidepressant use and 1.5 T MRI at baseline and after 3.9 ± 0.4 years of follow-up. Mood symptoms were assessed using the Mental Health Index (MHI-5). Depressed mood was defined as antidepressant use and/or MHI-5 score ≤ 52. Volumetric WML measures (deep and periventricular) were obtained with automated segmentation. Linear regression analyses were adjusted for age, sex, baseline WML volume, follow-up time, vascular risk factors and infarcts. Depressed mood was not associated with larger WML volume at baseline. However, when separate contributions were distinguished, antidepressant use was associated with greater deep (B = 0.50 mL, 95 % CI 0.04-0.96) and periventricular WML volume (B = 0.47 mL, 95 % CI 0.05-0.89) at baseline, while mood symptoms were not. Antidepressants were associated with a modest but non-significant increase in progression of periventricular WML volume over 4 years of follow-up (B = 0.21 mL, 95 % CI -0.05 to 0.47). WML at baseline were not associated with new-onset depressed mood at follow-up. Antidepressants, but not mood symptoms, were associated with greater WML volume and a modest, although non-significant increase in periventricular WML volume in patients with symptomatic atherosclerotic disease. Future studies are needed to determine whether this may be a direct effect, or whether other underlying diseases for which antidepressants are prescribed influence this relation.

Depressive symptoms, antidepressant use, and future cognitive health in postmenopausal women: the Women's Health Initiative Memory Study

BACKGROUND

Antidepressants are commonly prescribed medications in the elderly, but their relationship with incident mild cognitive impairment (MCI) and probable dementia is unknown.

METHODS

The study cohort included 6,998 cognitively healthy, postmenopausal women, aged 65-79 years, who were enrolled in a hormone therapy clinical trial and had baseline depressive symptoms and antidepressant use history assessments at enrollment, and at least one postbaseline cognitive measurement. Participants were followed annually and the follow-up averaged 7.5 years for MCI and probable dementia outcomes. A central adjudication committee classified the presence of MCI and probable dementia based on extensive neuropsychiatric examination.

RESULTS

Three hundred and eighty-three (5%) women were on antidepressants at baseline. Antidepressant use was associated with a 70% increased risk of MCI, after controlling for potential covariates including the degree of depressive symptom severity. Selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs) were both associated with MCI (SSRIs: hazard ratios (HR), 1.78 [95% CI, 1.01-3.13]; TCAs: HR, 1.78 [95% CI, 0.99-3.21]). Depressed users (HR, 2.44 [95% CI, 1.24-4.80]), non-depressed users (HR, 1.79 [95% CI, 1.13-2.85]), and depressed non-users (HR, 1.62 [95% CI, 1.13-2.32]) had increased risk of incident MCI. Similarly, all three groups had increased risk of either MCI or dementia, relative to the control cohort.

CONCLUSIONS

Antidepressant use and different levels of depression severity were associated with subsequent cognitive impairment in a large cohort of postmenopausal women. Future research should examine the role of antidepressants in the depression-dementia relationship and determine if antidepressants can prevent incident MCI and dementia in individuals with late-life depression subtypes with different levels of severity.

White matter abnormalities and illness severity in major depressive disorder

BACKGROUND

White matter abnormalities have been implicated in the aetiology of major depressive disorder; however, the relationship between the severity of symptoms and white matter integrity is currently unclear.

AIMS

To investigate white matter integrity in people with major depression and healthy controls, and to assess its relationship with depressive symptom severity.

METHOD

Diffusion tensor imaging data were acquired from 66 patients with recurrent major depression and a control group of 66 healthy individuals matched for age, gender and IQ score, and analysed with tract-based spatial statistics. The relationship between white matter integrity and severity of depression as measured by the Beck Depression Inventory was examined.

RESULTS

Depressive illness was associated with widespread regions of decreased white matter integrity, including regions in the corpus callosum, superior longitudinal fasciculus and anterior corona radiata, compared with the control group. Increasing symptom severity was negatively correlated with white matter integrity, predominantly in the corpus callosum.

CONCLUSIONS

Widespread alterations in white matter integrity are evident in major depressive disorder. These abnormalities are heightened with increasing severity of depressive symptoms.

Brain ischemia changes the long term response to antidepressant drugs in mice

Depression is a frequent but often unrecognized and under treated complication of stroke that has scarcely been investigated in animal models particularly regarding treatment issues. Using the Forced Swim Test (FST) and testing spontaneous motor activity, we studied whether a transient focal cerebral ischemia modifies mice behaviours and antidepressant drug effects. We first evaluated whether FST realized 2 days or 1 week after brain reperfusion may be routinely used in male Swiss mice previously submitted to a 15, 30 or 60-min transient occlusion of the right middle cerebral artery. We then evaluated behavioural changes up to 5 weeks in mice previously submitted to a 15-min ischemia. Behaviours according to the administration of imipramine or fluvoxamine at 1 and 5 weeks after a 15-min ischemia were finally evaluated. Transient ischemia was associated with a decrease in immobility in the FST performed 2 days after reperfusion while no changes were observed in 1 and 5 weeks post-ischemia groups. Changes were related neither to brain ischemia duration nor to infarct volume. At both 1 and 5 weeks after brain ischemia, a dramatic decrease in the antidepressant response to imipramine related to a decrease in climbing behaviour was observed while the effects of fluvoxamine were improved through an increase in both climbing and swimming. Behaviours in the FST were unrelated to any spontaneous motor activity changes. Responses to anti-depressant drugs are strongly modified in mice previously submitted to brain ischemia. Present results underline that not all antidepressant drugs are appropriate after ischemic stroke.

Influence of white matter hyperintensities on the cognition of patients with Parkinson disease

BACKGROUND

White matter hyperintensities (WMH) have been associated with cognitive impairment in elderly persons and in patients with Alzheimer disease. However, the role of WMH in Parkinson disease (PD) dementia remains to be elucidated.

METHODS

The cohort for this study comprised 71 consecutive patients with PD, all of whom completed a clinical assessment, neuropsychologic investigation, and magnetic resonance imaging of brain. WMH were rated using the semiquantitative visual rating system proposed by Scheltens et al.

RESULTS

The PD dementia group had significantly more WMH than the PD without dementia group in the evaluated brain regions except for the infratentorial area. The WMH showed a significant correlation with age, Unified Parkinson's Disease Rating Scale, Mini-Mental State Examination, sum of the box of Clinical Dementia Rating, and many of the cognitive domains. The linear regression model showed that the WMH was independently associated with cognitive impairment in patients with PD, regardless of age, sex, duration or severity of PD symptoms, and vascular risk factors.

CONCLUSIONS

These findings confirm that WMH might be associated with cognitive decline in patients with PD, regardless of age, sex, education status, duration or severity of PD symptoms, and vascular risk factors. This result suggests that other nonvascular factors contribute to the progression of dementia in patients with PD.

[Diagnosis and treatment of subcortical vascular dementia]

Subcortical vascular dementia (SVD) exhibits relatively uniform clinical and pathological features among various subtypes of vascular dementia, and constitutes approximately half of vascular dementia in Japan. This subtype is further classified into Binswanger's type infarction and multiple lacunar infarctions. The former is characterized by diffuse white matter lesions, and the latter by lacunar infarctions. However, the both have common pathologic mechanism related to hypertensive small vessel changes. This paper overview the notion, clinical features, pathogenesis and treatment for SVD, and also refer to the recent topics related to Alzheimer's disease.

Serotonin transporter polymorphisms, microstructural white matter abnormalities and remission of geriatric depression

OBJECTIVE

This study compared microstructural abnormalities in depressed elders and controls and studied the association of the serotonin transporter gene status to white matter abnormalities and to remission of depression.

METHODS

The subjects were Caucasians with non-psychotic major depression and normal elders. Depressed subjects received escitalopram 10 mg daily for 12 weeks. Remission was defined as a HDRS score of 7 or below for 2 consecutive weeks. Diffusion tensor imaging was performed and voxel-based analysis of fractional anisotropy (FA) was conducted using age and mean diffusivity as covariates.

RESULTS

Depressed elders (N=27) had lower FA than controls (N=27) in several frontolimbic areas. Depressed elderly S-allele carriers also had lower FA than L homozygotes in frontolimbic brain areas, including the dorsal and rostral anterior cingulate, posterior cingulate, dorsolateral prefrontal and medial prefrontal regions, thalamus, and in other regions. S-allele carriers had a lower remission rate than L homozygotes.

LIMITATIONS

Small number of subjects, lack of random sampling, fixed antidepressant dose, short follow-up.

CONCLUSIONS

Lower FA was observed in several frontolimbic and other regions in depressed elders compared to controls. Depressed S-allele carriers had both microstructural white matter abnormalities in frontolimbic networks and a low remission rate. It remains unclear whether the risk for chronicity of geriatric depression in S-allele carriers is mediated by frontolimbic compromise. However, these observations set the stage for studies aiming to identify the relationship of S allele to impairment in specific frontolimbic functions interfering with response of geriatric depression to antidepressants.

ROBERTE. Research advances in geriatric depression

Technical advances have facilitated the exploration of factors related to geriatric depression and have helped generate novel biological and psychosocial treatment approaches. This review summarizes the main advancements in epidemiology, clinical presentation and course, genetics, and other areas of biological research. Treatment interventions outlined in this paper include electroconvulsive therapy, repetitive transcranial magnetic stimulation, magnetic seizure therapy, vagus nerve stimulation, deep brain stimulatn, depression prophylaxis, multidisciplinary approaches to depression treatment, and psychotherapy. Forms of psychotherapy for geriatric depression summarized include interpersonal psychotherapy, supportive psychotherapy, cognitive-behavioral therapy, problem-solving therapy, and ecosystem-focused therapy. Neuroimaging techniques based on magnetic resonance imaging are discussed briefly, including volumetric brain studies, diffusion tensor imaging, fractional anisotropy, fiber tractography, magnetization transfer imaging, and blood-oxygenation-level-dependent functional magnetic resonance imaging. Finally, treatment effectiveness is addressed in a discussion of new models to improve access to and quality of care offered in the community.

Differential impact of lacunes and microvascular lesions on poststroke depression

BACKGROUND AND PURPOSE

Previous studies have postulated that poststroke depression (PSD) might be related to cumulative vascular brain pathology rather than to the location and severity of a single macroinfarct. We performed a detailed analysis of all types of microvascular lesions and lacunes in 41 prospectively documented and consecutively autopsied stroke cases.

METHODS

Only cases with first-onset depression <2 years after stroke were considered as PSD in the present series. Diagnosis of depression was established prospectively using DSM-IV criteria for major depression. Neuropathological evaluation included bilateral semiquantitative assessment of microvascular ischemic pathology and lacunes; statistical analysis included Fisher exact test, Mann-Whitney U test, and regression models.

RESULTS

Macroinfarct site was not related to the occurrence of PSD for any of the locations studied. Thalamic and basal ganglia lacunes occurred significantly more often in PSD cases. Higher lacune scores in basal ganglia, thalamus, and deep white matter were associated with an increased PSD risk. In contrast, microinfarct and diffuse or periventricular demyelination scores were not increased in PSD. The combined lacune score (thalamic plus basal ganglia plus deep white matter) explained 25% of the variability of PSD occurrence.

CONCLUSIONS

The cumulative vascular burden resulting from chronic accumulation of lacunar infarcts within the thalamus, basal ganglia, and deep white matter may be more important than single infarcts in the prediction of PSD.

Serotonin transporter polymorphisms, microstructural white matter abnormalities and remission of geriatric depression

OBJECTIVE

This study compared microstructural abnormalities in depressed elders and controls and studied the association of the serotonin transporter gene status to white matter abnormalities and to remission of depression.

METHODS

The subjects were Caucasians with non-psychotic major depression and normal elders. Depressed subjects received escitalopram 10 mg daily for 12 weeks. Remission was defined as a HDRS score of 7 or below for 2 consecutive weeks. Diffusion tensor imaging was performed and voxel-based analysis of fractional anisotropy (FA) was conducted using age and mean diffusivity as covariates.

RESULTS

Depressed elders (N=27) had lower FA than controls (N=27) in several frontolimbic areas. Depressed elderly S-allele carriers also had lower FA than L homozygotes in frontolimbic brain areas, including the dorsal and rostral anterior cingulate, posterior cingulate, dorsolateral prefrontal and medial prefrontal regions, thalamus, and in other regions. S-allele carriers had a lower remission rate than L homozygotes.

LIMITATIONS

Small number of subjects, lack of random sampling, fixed antidepressant dose, short follow-up.

CONCLUSIONS

Lower FA was observed in several frontolimbic and other regions in depressed elders compared to controls. Depressed S-allele carriers had both microstructural white matter abnormalities in frontolimbic networks and a low remission rate. It remains unclear whether the risk for chronicity of geriatric depression in S-allele carriers is mediated by frontolimbic compromise. However, these observations set the stage for studies aiming to identify the relationship of S allele to impairment in specific frontolimbic functions interfering with response of geriatric depression to antidepressants.