Poststroke depression and lesion location revisited

Evaluation and Treatment of Depression in Stroke Patients: A Systematic Review

Those who received early diagnosis and treatment for poststroke depression had lower mortality rates, cognitive impairments, improved long-term disability, a higher quality of life, and lower rates of suicidal thoughts than those who did not. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 standards were used to conduct this systematic review. Until May 1, 2022, a systematic search was conducted utilizing ScienceDirect, Cochrane, PubMed, Google Scholar, and PubMed central databases, which have been used during the previous 10 years. Randomized controlled trials (RCTs), observational studies, systematic reviews, review articles, case reports, clinical studies, and meta-analyses were included in the research, which covered post-stroke depression patients and how to identify and treat them.

There were 545 possibly related titles found in the database search. Finally, each publication was given a quality rating, and 10 studies with a score of higher than 70% were allowed into the review. Because of their brevity and ease of use, they employed the Patient Health Questionnaire-9 (PHQ-9) and PHQ-2 screening instruments in stroke patients. According to pooled studies, the risk of acquiring post-stroke depression (PSD) was lower in participants undergoing pharmacological therapy with selective serotonin reuptake inhibitors (SSRIs), especially after a year. Identifying further features of the PSD process, we believe, is the most pressing need for future study since it might lead to a more precise treatment strategy.

Understanding Why Post-Stroke Depression May Be the Norm Rather Than the Exception: The Anatomical and Neuroinflammatory Correlates of Post-Stroke Depression

Ischemic Stroke precedes depression. Post-stroke depression (PSD) is a major driver for poor recovery, negative quality of life, poor rehabilitation outcomes and poor functional ability. In this systematic review, we analysed the inflammatory basis of post-stroke depression, which involves bioenergetic failure, deranged iron homeostasis (calcium influx, Na influx, potassium efflux etc), excitotoxicity, acidotoxicity, disruption of the blood brain barrier, cytokine-mediated cytotoxicity, reactive oxygen mediated toxicity, activation of cyclooxygenase pathway and generation of toxic products. This process subsequently results in cell death, maladapted, persistent neuro-inflammation and deranged neuronal networks in mood-related brain regions. Furthermore, an in-depth review likewise reveals that anatomic structures related to post-stroke depression may be localized to complex circuitries involving the cortical and subcortical regions.

Effect of intravenous alteplase on post-stroke depression in the WAKE UP trial

BACKGROUND AND PURPOSE

The aim was to study the effect of intravenous alteplase on the development of post-stroke depression (PSD) in acute stroke patients, and to identify predictors of PSD.

METHODS

This post hoc analysis included patients with unknown onset stroke randomized to treatment with alteplase or placebo in the WAKE-UP trial (ClinicalTrials.gov number, NCT01525290), in whom a composite end-point of PSD was defined as a Beck Depression Inventory ≥10, medication with an antidepressant, or depression recorded as an adverse event. Multiple logistic regression was used to identify predictors of PSD at 90 days. Structural equation modelling was applied to assess the indirect effect of thrombolysis on PSD mediated by the modified Rankin Scale.

RESULTS

Information on the composite end-point was available for 438 of 503 randomized patients. PSD was present in 96 of 224 (42.9%) patients in the alteplase group and 115 of 214 (53.7%) in the placebo group (odds ratio 0.63; 95% confidence interval 0.43-0.94; p = 0.022; adjusted for age and National Institutes of Health Stroke Scale at baseline). Prognostic factors associated with PSD included baseline medication with antidepressants, higher lesion volume, history of depression and assignment to placebo. While 65% of the effect of thrombolysis on PSD were caused directly, 35% were mediated by an improvement of the mRS.

CONCLUSIONS

Treatment with alteplase in patients with acute stroke resulted in lower rates of depression at 90 days, which were only partially explained by reduced functional disability. Predictors of PSD including history and clinical characteristics may help in identifying patients at risk of PSD.

First evidence of protective effects on stroke recovery and post-stroke depression induced by sortilin-derived peptides

Post-stroke depression (PSD) is the most common mood disorder following stroke with high relevance for outcome and survival of patients. The TREK-1 channel represents a crucial target in the pathogenesis of stroke and depression. Spadin and its short analog mini-spadin were reported to display potent antidepressant properties. We investigated the therapeutic effects of mini-spadin in a mouse model of focal ischemia and PSD. To activate TREK-1 and induce neuroprotection a single low dose of mini-spadin (0.03 μg/kg) was intraperitoneally injected 30  min after the onset of ischemia, once a day during 7 days post-ischemia. Then, to inhibit TREK-1 and induce antidepressant effect, the peptide was injected at higher concentration (3 μg/kg) once a day for 4 days/week until the sacrifice of animals. Electrophysiological studies showed that mini-spadin had a biphasic action on TREK-1. At low doses, the channel activity was increased whereas at higher doses it was inhibited. Mini-spadin prevented the loss of body weight and the delayed dopaminergic degeneration in substantia nigra and improved the motor and cognitive ischemia-induced deficits. Moreover, mini-spadin prevented PSD analyzed in the Forced Swim (FST) and Novelty Suppressed Feeding (NSF) tests. Finally, enhanced neurogenesis and synaptogenesis contributed to the beneficial effects of mini-spadin against stroke and PSD. This work reveals the first evidence that the modulation of TREK-1 channels in the early and chronic phases of stroke as well as the stimulation of brain plasticity by mini-spadin could play a key role in its brain protective effects against stroke and its deleterious consequences such as PSD.

Altered Topology of the Structural Brain Network in Patients With Post-stroke Depression

There is a pressing need to further our understanding of the mechanisms underlying the depression symptoms in patients with post-stroke depression (PSD) in order to inform targeted therapeutic approaches. While previous research has demonstrated a reorganization in the functional brain network of PSD, it remains uncertain whether, or not it also occurs in the structural brain network. We therefore aim to investigate the structural brain network of patients with PSD as compared to post-stroke non-depression (PSND) patients. In addition, our research considers the relationship between network metrics and functional measurements. Thirty-one PSD patients and twenty-three PSND patients were recruited. All patients underwent MRI and functional assessments, including the Barthel index, mini-mental state examination (MMSE), and Hamilton depression rating scale (HAMD). Diffusion tensor imaging was used to construct the structural brain network and to conduct the subsequent graph theoretical analysis. Network measures were computed and compared between PSD and PSND patients. Associations between functional assessments and network measures were studied as well. We successfully detected increased global and local efficiency in patients with PSD. Regions with disrupted local connections were located primarily in the cognitive and limbic systems. More importantly, PSD patients' global and regional network measures were associated with depression severity, as measured by HAMD. These findings suggest that disrupted global and local network topologies might contribute to PSD patients' depression symptoms. Therefore, connectome-based network measures could be potential bio-markers for evaluating stroke patients' depression levels.

Neural reward response to substance-free activity images in opiate use disorder patients with depressive symptoms

BACKGROUND

Deficits in the ability to experience reward from natural, substance-free activities and stimuli is a common mechanism contributing to both opiate use disorder and depressive symptoms, and is a target of behavioral-focused treatments for substance use and depression. Although the neural response to monetary, positive affect-eliciting and social images has been investigated, the neural response to images representing substance-free activity engagement remains untested. The current study tested the neural response to anticipation and receipt of substance-free activity engagement images and monetary reward in opiate use disorder patients with elevated depressive symptoms compared to healthy controls.

METHODS

Sixteen male opiate use disorder detoxification patients with elevated depressive symptoms (Beck Depression Inventory (BDI-II) ≥ 14) (OUDD M_age = 32.19 years, SD = 8.17 years) and seventeen male healthy controls (BDI-II < 14) (HC: M_age = 26.82 years, SD = 5.29 years) completed the Monetary Incentive Delay (MID) and newly developed Activity Incentive Delay (AID) tasks. Within- and between-group whole-brain contrasts tested activation during anticipation ([reward]-[non-reward]) and receipt ([win]-[non-win]) of substance-free activity image, monetary, and substance-free activity relative to monetary (AID-MID), reward.

RESULTS

OUDD demonstrated significantly lower activation in reward regions during anticipation and significantly greater activation during receipt of substance-free activity image reward compared to HC. OUDD demonstrated significantly lower activation during anticipation of substance-free activity reward relative to monetary reward, compared to HC.

CONCLUSIONS

The observed reduction in frontostriatal response to reward anticipation of substance-free activity engagement images in OUDD, yet increased neural response to reward receipt, supports theory linking reductions in reward processing with deficits in motivation for substance-free activity engagement.

A cross-sectional study to assess the association between major depression and inflammatory markers in patients with acute ischemic stroke

BACKGROUND

Increased interest in the relationship between affective disorder and long-term health consequences has generated recent examinations of depression and stroke. Observations suggest that depressive disorder is associated with abnormal physiological and immunological responses and a resultant increase in inflammatory markers. Given the high prevalence of stroke and associated costs for the community, it is important to understand the mechanisms that may impact on the outcome to achieve the best possible prognosis.

AIMS

The view that inflammatory factors contribute to depression is predicated on findings that circulating cytokines and other inflammatory factors are increased in depressed patients. Therefore, it has been hypothesized that inflammation could be one of the mechanisms by which depression increases risk for ischemic stroke. Our aim was to determine whether there is any relationship between major depression and tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), IL-18, brain-derived neurotrophic factor (BDNF), and neuron-specific enolase (NSE) in patients with acute ischemic stroke (AIS).

STUDY DESIGN

This was as a cross-sectional design.

MATERIALS AND METHODS

This study has a cross-sectional design, and it was conducted in Necmettin Erbakan University, the Meram Faculty of Medicine in Konya, Turkey, between 2014 and 2015. Fifty-three AIS patients admitted to the hospital within the first 24 h after stroke onset were recruited. Major depression was ascertained by means of the structured clinical interview for the diagnostic and statistical manual of mental disorders, Fourth Edition/Clinical Version. The enzyme-linked immunosorbent assay was used to measure the serum levels of TNF-α, IL-1 β, IL-18, BDNF, and NSE at admission.

RESULTS

A total of 53 patients with a mean age of 65.9 years were recruited. Of these patients, 17 (32.1%) had major depression. Depressive and nondepressive patients had similar demographical and clinical features. There was no significant statistical difference between depressive and nondepressive patients with AIS with respect to levels of TNF-α, IL-1 β, IL-18, BDNF, and NSE.

CONCLUSION

This study suggests that in patients who have experienced AIS, there is no significant relationship between major depression and basal proinflammatory cytokines (TNF-α, IL-1 β, IL-18), BDNF, and NSE.

Predictors of Remission of Early-Onset Poststroke Depression and the Interaction Between Depression and Cognition During Follow-Up

Objectives: This study aimed to examine the rate of remission in individuals experiencing early-onset poststroke depression (PSD) in China and to identify predictors of remission during a 3-month follow-up. This study also explored the interaction between cognitive impairment and depression. Methods: A total of 820 patients with PSD from a massive multicenter prospective cohort project in China (PRIOD) were included in the present study. Depressive symptoms were measured with the Hamilton Depression Rating Scale (17 Items, HDRS-17) at 2 weeks and the endpoint of the 3-month follow-up. The cut-off score of HDRS-17 (< 8) was used to define remission of depression at the endpoint. The Mini-Mental State Exam (MMSE) was used to evaluate the cognitive impairment of the patients (at the 2-week follow-up and 3-month endpoint). The National Institutes of Health Stroke Scale (NIHSS) was used to measure the severity of stroke. Results: (1) Six hundred and forty-two patients completed the 3-month follow-up, and 332 (51.7%) patients remitted by the end of the study. Univariate analyses indicated that there was a higher proportion of patients who had hypertension, frontal lobe lesion, basal ganglia lesion, poor outcome at 2 weeks, high scores on the NIHSS at 2 weeks, major life events within 3 months, and major medical diseases within 3 months in the nonremission group. In stepwise multiple logistic regression analyses, remission was significantly predicted by lower NIHSS scores at 2 weeks (p = 0.001, OR = 1.086, 95% CI 1.035-1.139), fewer major life events (p = 0.036, OR = 5.195, 95% CI 1.111-27.283), fewer major medical comorbidities (p = 0.015, OR = 2.434, 95% CI 1.190-4.979), and fewer frontal lobe lesions (p = 0.042, OR = 1.717, 95% CI 1.019-2.891). (2) After controlling for confounding variables, repeated measures analysis of variance revealed a significant interaction between time (2 weeks vs. 3 months) and group (remitters vs. nonremitters) on MMSE scores [F (1, 532) = 20.2, p < 0.001]. Conclusions: Early-onset PSD patients with milder neurological impairment, fewer major life events, fewer major medical comorbidities and no frontal lobe lesion at baseline were more likely to achieve remission 3 months after stroke. Only remitters of PSD improved significantly in cognitive impairment after stroke. The PRIOD trial is registered at http://www.isrctn.com/, number ISRCTN62169508.

Poststroke Depression Biomarkers: A Narrative Review

Poststroke depression (PSD) is the most prevalent psychiatric disorder after stroke, which is independently correlated with negative clinical outcome. The identification of specific biomarkers could help to increase the sensitivity of PSD diagnosis and elucidate its pathophysiological mechanisms. The aim of current study was to review and summarize literature exploring potential biomarkers for PSD diagnosis. The PubMed database was searched for papers published in English from October 1977 to December 2017, 90 of which met inclusion criteria for clinical studies related to PSD biomarkers. PSD biomarkers were subdivided into neuroimaging, molecular, and neurophysiological. Some of them could be recommended to support PSD diagnosing. According to the data, lesions affecting the frontal-subcortical circles of mood regulation (prefrontal cortex, basal nuclei, and thalamus) predominantly in the left hemisphere can be considered as neuroimaging markers and predictors for PSD for at least 1 year after stroke. Additional pontine and lobar cerebral microbleeds in acute stroke patients, as well as severe microvascular lesions of the brain, increase the likelihood of PSD. The following molecular candidates can help to differentiate PSD patients from non-depressed stroke subjects: decreased serum BDNF concentrations; increased early markers of inflammation (high-sensitivity C-reactive protein, ferritin, neopterin, and glutamate), serum pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-18, IFN-γ), as well as pro-inflammatory/anti-inflammatory ratios (TNF-α/IL-10, IL-1β/IL-10, IL-6/IL-10, IL-18/IL-10, IFN-γ/IL-10); lowered complement expression; decreased serum vitamin D levels; hypercortisolemia and blunted cortisol awakening response; S/S 5-HTTLPR, STin2 9/12, and 12/12 genotypes of the serotonin transporter gene SLC6A4, 5-HTR2a 1438 A/A, and BDNF met/met genotypes; higher SLC6A4 promoter and BDNF promoter methylation status. Neurophysiological markers of PSD, that reflect a violation of perception and cognitive processing, are the elongation of the latency of N200, P300, and N400, as well as the decrease in the P300 and N400 amplitude of the event-related potentials. The selected panel of biomarkers may be useful for paraclinical underpinning of PSD diagnosis, clarifying various aspects of its multifactorial pathogenesis, optimizing therapeutic interventions, and assessing treatment effectiveness.

Diversiform Etiologies for Post-stroke Depression

After the onset of stroke, many patients suffer from emotional behavior changes. Approximately, one-third of stroke survivors are affected by post-stroke depression (PSD), making it a serious social and public health problem. Post-stroke depression (PSD) has an important impact on the course, recovery, and prognosis of stroke. The pathogenesis of PSD is very complex, involving many factors such as biological mechanism and social psychological mechanisms. This article provides a brief review of the hot issues related to etiologies of PSD.

The factors related to early-onset depression after first stroke

BACKGROUND

The biological and psychological aspects of post-stroke depression (PSD) may vary based on the time since stroke onset. The sociodemographic and clinical correlates of early-onset PSD are not yet well understood. In the present study, we aimed to investigate the clinical correlates of early-onset depression following first stroke. We hypothesized that the severity of a stroke or disability (other than lesion characteristics) would likely be related to PSD in a sample of first stroke patients with single and unilateral lesions.

METHODS

Post-stroke patients with (n = 40) and without (n = 51) early-onset depression were compared with respect to several demographic and clinical variables.

RESULTS

There were no significant differences between the groups with respect to lesion location, lateralization, or volume. Scores on the Brief Disability Questionnaire, National Institutes of Health Stroke Scale, and Modified Rankin Scale were significantly higher in depressed post-stroke patients than in non-depressed patients. The anxiety, depression, and total scores of the Hospital Anxiety and Depression Scale were positively correlated with the Modified Rankin Scale, National Institutes of Health Stroke Scale, and Brief Disability Questionnaire scores. A previous history of depression and Brief Disability Questionnaire score were strongly associated with the occurrence of early-onset PSD.

CONCLUSION

Our findings suggest that early-onset PSD is likely to be correlated with the severity of stroke and functional disability.

Post-Stroke Depression: Impact of Lesion Location and Methodological Limitations-A Topical Review

Post-stroke depression (PSD) affects approximately one-third of all stroke patients. It hinders rehabilitation and is associated with worse functional outcome and increased mortality. Since the identification of PSD is a significant clinical problem, clinicians and researchers have tried to identify predictors that indicate patients at risk of developing PSD. This also includes the research question whether there is an association between PSD and stroke lesion characteristics, e.g., lesion size and lesion location. Early studies addressing this question are largely limited by technical constraints and, thus, focused on simple lesion characteristics such as lesion side or proximity of the lesion to the frontal pole of the brain. More recent studies have addressed the impact of involvement of specific neuronal circuits in the stroke lesion. State-of-the-art methods of lesion symptom mapping to study PSD have only been applied to small patient samples. Overall, results are controversial and no clear pattern of stroke lesions associated with PSD has emerged, though there are findings suggesting that more frontal stroke lesions are associated with higher incidence of PSD. Available studies are hampered by methodological limitations, including drawbacks of lesion analysis methods, small sample size, and the issue of patient selection. These limitations together with differences in approaches to assess PSD and in methods of image analysis limit the comparability of results from different studies. To summarize, as of today no definite association between lesion location and PSD can be ascertained and the understanding of PSD rests incomplete. Further insights are expected from the use of modern lesion inference analysis methods in larger patient samples taking into account standardized assessment of possible confounding parameters, such as stroke treatment and reperfusion status.

Connectivity-based parcellation of the anterior limb of the internal capsule

The anterior limb of the internal capsule (ALIC) is an important locus of frontal-subcortical fiber tracts involved in cognitive and limbic feedback loops. However, the structural organization of its component fiber tracts remains unclear. Therefore, although the ALIC is a promising target for various neurosurgical procedures for psychiatric disorders, more precise understanding of its organization is required to optimize target localization. Using diffusion tensor imaging (DTI) collected on healthy subjects by the Human Connectome Project (HCP), we generated parcellations of the ALIC by dividing it according to structural connectivity to various frontal regions. We then compared individuals' parcellations to evaluate the ALIC's structural consistency. All 40 included subjects demonstrated a posterior-superior to anterior-inferior axis of tract organization in the ALIC. Nonetheless, subdivisions of the ALIC were found to vary substantially, as voxels in the average parcellation were accurately assigned for a mean of only 66.2% of subjects. There were, however, some loci of consistency, most notably in the region maximally connected to orbitofrontal cortex. These findings clarify the highly variable organization of the ALIC and may represent a tool for patient-specific targeting of neuromodulation. Hum Brain Mapp 38:6107-6117, 2017. © 2017 Wiley Periodicals, Inc.

Risk Factors for Post-stroke Depression: A Meta-analysis

Background: Stroke not only impacts patients physically but also economically. Post-stroke depression (PSD), as a common complication of stroke, always obstructs the process of stroke rehabilitation. Accordingly, defining the risk factors associated with PSD has extraordinary importance. Although there have been many studies investigating the risk factors for PSD, the results are inconsistent.

Objectives: The objectives of this study were to identify the risk factors for PSD by evidence-based medicine.

Data sources: A systematic and comprehensive database search was performed of PubMed, Medline, CENTRAL, EMBASE.com, the Cochrane library and Web of Science for Literature, covering publications from January 1, 1998 to November 19, 2016.

Study Selection: Studies on risk factors for PSD were identified, according to inclusion and exclusion criteria. The risk of bias tool, described in the Cochrane Handbook version 5.1.0, was used to assess the quality of each study. Meta-analysis was performed using RevMan 5.3 software.

Results: Thirty-six studies were included for review. A history of mental illness was the highest ranking modifiable risk factor; other risk factors for PSD were female gender, age (<70 years), neuroticism, family history, severity of stroke, and level of handicap. Social support was a protective factor for PSD.

Conclusion: There are many factors that have effects on PSD. The severity of stroke is an important factor in the occurrence of PSD. Mental history is a possible predictor of PSD. Prevention of PSD requires social and family participation.

Depression and Anxiety Across the First Year After Ischemic Stroke: Findings from a Population-Based New Zealand ARCOS-IV Study

Background: Depression and anxiety are the two most frequently studied emotional outcomes of stroke. However, few previous studies have been carried out at a population level or beyond 6 months post stroke. The aim of this study was to describe depression and anxiety across the first year following incident ischemic stroke (IS), and identify predictive factors in a population-based study.

Method: The Hospital Anxiety Depression Scale (HADS) was administered at baseline (within 2 weeks of onset), and again at 1-month, 6-months and 12-months after IS in a sample (N = 365) drawn from a population-based study.

Results: Over 75% of those assessed experienced depression or anxiety symptoms below cut-offs for probable disorder across the year post stroke. Moderate to severe symptoms for anxiety were approximately twice as likely (range 4.1%–10.6%) as compared to depression (range 2.5%–5.0%) at each assessment. The greatest improvement in anxiety occurred within the first month post stroke. In contrast, the greatest reduction in depression occurred between 1- to 6-months post stroke.

Conclusions: Anxiety symptoms in the moderate to severe range were twice as common as depression, and improved over the first month post stroke, whilst depression symptoms persisted for up to 6 months, indicating a need to target these two issues at different points in the recovery process.

Psychiatric Hospitalization Increases Short-Term Risk of Stroke

BACKGROUND AND PURPOSE

Recent evidence suggests that psychological distress, including the symptoms of psychiatric illness, may acutely increase the risk of stroke. However, existing studies are limited by small sample sizes, inherent recall bias, and poorly defined criteria for what constitutes psychological distress.

METHODS

We analyzed administrative data from the Healthcare Cost and Utilization Project for the state of California from 2007 to 2009 using a case-crossover design. Conditional logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (95% CIs) for combined hemorrhagic and ischemic stroke risk occurring within 15, 30, 90, 180, and 365 days of a hospitalization for a psychiatric diagnosis (as defined by International Classification of Diseases, Ninth Revision, code) among adults.

RESULTS

Psychiatric hospitalizations within 1 year before stroke were found in 2585 (5.3%) of 48 558 stroke patients. Hospitalization for a psychiatric condition was associated with increased risk of stroke within all 5 time periods, with the highest odds of stroke occurring within 15 days (0-15 days: OR, 3.5; 95% confidence interval [CI], 2.6-4.8; 0-30 days: OR, 3.0; 95% CI, 2.4-3.8; 0-90 days: OR, 2.3; 95% CI, 2.0-2.7; 0-180 days: OR, 2.2; 95% CI, 2.0-2.5; and 0-365 days: OR, 2.6; 95% CI, 2.4-2.8).

CONCLUSIONS

Psychiatric hospitalization increases the short-term risk of stroke, particularly within the 15-day period after hospitalization.

Altered neuronal spontaneous activity correlates with glutamate concentration in medial prefrontal cortex of major depressed females: An fMRI-MRS study

BACKGROUND

Major depressive disorder (MDD) is twice more prevalent in females than in males. Yet, there have only been a few studies on the functional brain activity in female MDD patients and the detailed mechanisms underlying their neurobiology merit further investigations. In the present work, we used combined fMRI-MRS methods to investigate the altered intrinsic neuronal activity and its association with neurotransmitter concentration in female MDD patients.

METHODS

The whole brain amplitude of low frequency fluctuation (ALFF) analysis using resting state functional magnetic resonance imaging (fMRI) was performed to explore the alteration of intrinsic neuronal signals in MDD females (n=11) compared with female healthy controls (n=11). With a specific interest in the medial prefrontal cortex (mPFC) area, we quantified the concentration of amino acid neurotransmitters including GABA ((r-aminobutyric acid)), Glu (Glutamate), and Glx (Glutamate + Glutamine) using (1)H-MRS technology. Moreover, we conducted Pearson correlation analysis between the ALFF value and neurotransmitter concentration to find out the functional-biochemical relation in mPFC area. The relationship between the metabolites concentration and MDD symptomatology was also examined through Spearman correlation analysis.

RESULTS

We found that the female MDD patients showed increased neuronal spontaneous activity in left medial prefrontal cortex (mPFC) and left middle frontal cortex, with decreased ALFF level in right putamen and right middle temporal cortex (p<0.01, Alphasim corrected). The ALFF in mPFC was shown positively correlated with Glu concentration in female MDD patients (r=0.67, p=0.023). The Glu concentration in mPFC was positively correlated with patients HAMA scores (r=0.641, p=0.033).

LIMITATIONS

The relatively small sample size, metabolite information acquired only in mPFC and not all patients were unmedicated are the major limitations of our study.

CONCLUSIONS

Using combined fMRI-MRS methods, we found increased spontaneous neuronal activity was correlated with Glu concentration in mPFC of female MDD patients. Other regions including left middle frontal gyrus, right putamen and middle temporal gyrus also showed altered spontaneous neuronal activities. The abnormal intrinsic neuronal activities in fronto-cortical regions shed light on the pathogenesis underlying MDD females. The multimodal resting-state neuroimaging technique served as a useful tool for functional-biochemical investigation of MDD pathophysiology.

Correlation between Motor Cortex Excitability Changes and Cognitive Impairment in Vascular Depression: Pathophysiological Insights from a Longitudinal TMS Study

Background. Transcranial magnetic stimulation (TMS) highlighted functional changes in dementia, whereas there are few data in patients with vascular cognitive impairment-no dementia (VCI-ND). Similarly, little is known about the neurophysiological impact of vascular depression (VD) on deterioration of cognitive functions. We test whether depression might affect not only cognition but also specific cortical circuits in subcortical vascular disease. Methods. Sixteen VCI-ND and 11 VD patients, age-matched with 15 controls, underwent a clinical-cognitive, neuroimaging, and TMS assessment. After approximately two years, all participants were prospectively reevaluated. Results. At baseline, a significant more pronounced intracortical facilitation (ICF) was found in VCI-ND patients. Reevaluation revealed an increase of the global excitability in both VCI-ND and VD subjects. At follow-up, the ICF of VCI-ND becomes similar to the other groups. Only VD patients showed cognitive deterioration. Conclusions. Unlike VD, the hyperfacilitation found at baseline in VCI-ND patients suggests enhanced glutamatergic neurotransmission that might contribute to the preservation of cognitive functioning. The hyperexcitability observed at follow-up in both groups of patients also indicates functional changes in glutamatergic neurotransmission. The mechanisms enhancing the risk of dementia in VD might be related either to subcortical vascular lesions or to the lack of compensatory functional cortical changes.

Alterations in the corticotropin-releasing hormone (CRH) neurocircuitry: Insights into post stroke functional impairments

Although it is well accepted that changes in the regulation of the hypothalamic-pituitary adrenal (HPA) axis may increase susceptibility to affective disorders in the general population, this link has been less examined in stroke patients. Yet, the bidirectional association between depression and cardiovascular disease is strong, and stress increases vulnerability to stroke. Corticotropin-releasing hormone (CRH) is the central stress hormone of the HPA axis pathway and acts by binding to CRH receptors (CRHR) 1 and 2, which are located in several stress-related brain regions. Evidence from clinical and animal studies suggests a role for CRH in the neurobiological basis of depression and ischemic brain injury. Given its importance in the regulation of the neuroendocrine, autonomic, and behavioral correlates of adaptation and maladaptation to stress, CRH is likely associated in the pathophysiology of post stroke emotional impairments. The goals of this review article are to examine the clinical and experimental data describing (1) that CRH regulates the molecular signaling brain circuit underlying anxiety- and depression-like behaviors, (2) the influence of CRH and other stress markers in the pathophysiology of post stroke emotional and cognitive impairments, and (3) context and site specific interactions of CRH and BDNF as a basis for the development of novel therapeutic targets. This review addresses how the production and release of the neuropeptide CRH within the various regions of the mesocorticolimbic system influences emotional and cognitive behaviors with a look into its role in psychiatric disorders post stroke.

A Pathway Proteomic Profile of Ischemic Stroke Survivors Reveals Innate Immune Dysfunction in Association with Mild Symptoms of Depression - A Pilot Study

Depression after stroke is a common occurrence, raising questions as to whether depression could be a long-term biological and immunological sequela of stroke. Early explanations for post-stroke depression (PSD) focused on the neuropsychological/psychosocial effects of stroke on mobility and quality of life. However, recent investigations have revealed imbalances of inflammatory cytokine levels in association with PSD, though to date, there is only one published proteomic pathway analysis testing this hypothesis. Thus, we examined the serum proteome of stroke patients (n = 44, mean age = 63.62 years) and correlated these with the Montgomery–Åsberg Depression Rating Scale (MADRS) scores at 3 months post-stroke. Overall, the patients presented with mild depression symptoms on the MADRS, M = 6.40 (SD = 7.42). A discovery approach utilizing label-free relative quantification was employed utilizing an LC-ESI–MS/MS coupled to a LTQ-Orbitrap Elite (Thermo-Scientific). Identified peptides were analyzed using the gene set enrichment approach on several different genomic databases that all indicated significant downregulation of the complement and coagulation systems with increasing MADRS scores. Complement and coagulation systems are traditionally thought to play a key role in the innate immune system and are established precursors to the adaptive immune system through pro-inflammatory cytokine signaling. Both systems are known to be globally affected after ischemic or hemorrhagic stroke. Thus, our results suggest that lowered complement expression in the periphery in conjunction with depressive symptoms post-stroke may be a biomarker for incomplete recovery of brain metabolic needs, homeostasis, and inflammation following ischemic stroke damage. Further proteomic investigations are now required to construct the temporal profile, leading from acute lesion damage to manifestation of depressive symptoms. Overall, the findings provide support for the involvement of inflammatory and immune mechanisms in PSD symptoms and further demonstrate the value and feasibility of the proteomic approach in stroke research.

Mania secondary to focal brain lesions: implications for understanding the functional neuroanatomy of bipolar disorder

OBJECTIVES

Approximately 3.5 million Americans will experience a manic episode during their lifetimes. The most common causes are psychiatric illnesses such as bipolar I disorder and schizoaffective disorder, but mania can also occur secondary to neurological illnesses, brain injury, or neurosurgical procedures.

METHODS

For this narrative review, we searched Medline for articles on the association of mania with stroke, brain tumors, traumatic brain injury, multiple sclerosis, neurodegenerative disorders, epilepsy, and neurosurgical interventions. We discuss the epidemiology, features, and treatment of these cases. We also review the anatomy of the lesions, in light of what is known about the neurobiology of bipolar disorder.

RESULTS

The prevalence of mania in patients with brain lesions varies widely by condition, from <2% in stroke to 31% in basal ganglia calcification. Mania occurs most commonly with lesions affecting frontal, temporal, and subcortical limbic brain areas. Right-sided lesions causing hypo-functionality or disconnection (e.g., stroke; neoplasms) and left-sided excitatory lesions (e.g., epileptogenic foci) are frequently observed.

CONCLUSIONS

Secondary mania should be suspected in patients with neurological deficits, histories atypical for classic bipolar disorder, and first manic episodes after the age of 40 years. Treatment with antimanic medications, along with specific treatment for the underlying neurologic condition, is typically required. Typical lesion locations fit with current models of bipolar disorder, which implicate hyperactivity of left-hemisphere reward-processing brain areas and hypoactivity of bilateral prefrontal emotion-modulating regions. Lesion studies complement these models by suggesting that right-hemisphere limbic-brain hypoactivity, or a left/right imbalance, may be relevant to the pathophysiology of mania.

Relationship between G1287A of the NET Gene Polymorphisms and Brain Volume in Major Depressive Disorder: A Voxel-Based MRI Study

Background

Earlier studies implicated norepinephrine transporter (NET) gene (SLC6A2) polymorphisms in the etiology of major depressive disorder (MDD). Recently, two single nucleotide SLC6A2 polymorphisms, G1287A in exon 9 and T-182C in the promoter region, were found to be associated with MDD in different populations. We investigated the relationship between the brain volume and these two polymorphisms of the SLC6A2 in MDD patients.

Methods

We obtained 3D high-resolution T1-weighted images of 30 first-episode MDD patients and 48 age- and sex-matched healthy subjects (HS). All were divided into 4 groups based on polymorphism of either the G1287A or the T-182C genotype. VBM analysis examined the effects of diagnosis, genotype, and genotype-diagnosis interactions.

Results

Diagnosis effects on the brain morphology were found in the left superior temporal cortex. No significant genotype effects were found in the T-182C and the G1287A. A significant genotype (G1287A)–diagnosis interaction was found in the left dorsolateral prefrontal cortex. No significant genotype (T-182C)–diagnosis interaction effects were observed in any brain region.

Conclusions

In MDD patients there seems to be a relationship between the volume of the dorsolateral prefrontal cortex and polymorphism of the SLC6A2 G1287A gene.

Human Frontal-Subcortical Circuit and Asymmetric Belief Updating

How humans integrate information to form beliefs about reality is a question that has engaged scientists for centuries, yet the biological system supporting this process is not well understood. One of the most salient attributes of information is valence. Whether a piece of news is good or bad is critical in determining whether it will alter our beliefs. Here, we reveal a frontal-subcortical circuit in the left hemisphere that is simultaneously associated with enhanced integration of favorable information into beliefs and impaired integration of unfavorable information. Specifically, for favorable information, stronger white matter connectivity within this system, particularly between the left inferior frontal gyrus (IFG) and left subcortical regions (including the amygdala, hippocampus, thalamus, putamen, and pallidum), as well as insular cortex, is associated with greater change in belief. However, for unfavorable information, stronger connectivity within this system, particularly between the left IFG and left pallidum, putamen, and insular cortex, is associated with reduced change in beliefs. These novel results are consistent with models suggesting that partially separable processes govern learning from favorable and unfavorable information.

SIGNIFICANCE STATEMENT

Beliefs of what may happen in the future are important, because they guide decisions and actions. Here, we illuminate how structural brain connectivity is related to the generation of subjective beliefs. We focus on how the valence of information is related to people's tendency to alter their beliefs. By quantifying the extent to which participants update their beliefs in response to desirable and undesirable information and relating those measures to the strength of white matter connectivity using diffusion tensor imaging, we characterize a left frontal-subcortical system that is associated simultaneously with greater belief updating in response to favorable information and reduced belief updating in response to unfavorable information. This neural architecture may allow valence to be incorporated into belief updating.

Correlation between Motor Cortex Excitability Changes and Cognitive Impairment in Vascular Depression: Pathophysiological Insights from a Longitudinal TMS Study

Background. Transcranial magnetic stimulation (TMS) highlighted functional changes in dementia, whereas there are few data in patients with vascular cognitive impairment-no dementia (VCI-ND). Similarly, little is known about the neurophysiological impact of vascular depression (VD) on deterioration of cognitive functions. We test whether depression might affect not only cognition but also specific cortical circuits in subcortical vascular disease. Methods. Sixteen VCI-ND and 11 VD patients, age-matched with 15 controls, underwent a clinical-cognitive, neuroimaging, and TMS assessment. After approximately two years, all participants were prospectively reevaluated. Results. At baseline, a significant more pronounced intracortical facilitation (ICF) was found in VCI-ND patients. Reevaluation revealed an increase of the global excitability in both VCI-ND and VD subjects. At follow-up, the ICF of VCI-ND becomes similar to the other groups. Only VD patients showed cognitive deterioration. Conclusions. Unlike VD, the hyperfacilitation found at baseline in VCI-ND patients suggests enhanced glutamatergic neurotransmission that might contribute to the preservation of cognitive functioning. The hyperexcitability observed at follow-up in both groups of patients also indicates functional changes in glutamatergic neurotransmission. The mechanisms enhancing the risk of dementia in VD might be related either to subcortical vascular lesions or to the lack of compensatory functional cortical changes.

Major Depression as a Predictor of Poor Long-Term Survival in a Brazilian Stroke Cohort (Study of Stroke Mortality and Morbidity in Adults) EMMA study

BACKGROUND

The influence of poststroke depression on long-term survival is poorly investigated. Thus, we aimed to evaluate the influence of major depression disorder (MDD) on long-term survival in the participants from The Study of Stroke Mortality and Morbidity in Adults (EMMA Study) in São Paulo, Brazil.

METHODS

We prospectively evaluated ischemic and hemorrhagic stroke (HS) cases from the EMMA Study. Baseline and stroke characteristics and cardiovascular risk factors were evaluated according to MDD assessed by the Patient Health Questionnaire, which was applied 30 days after index event and periodically during 1-year follow-up. We performed Kaplan-Meier survival analysis, as well as crude and multiple Cox proportional hazards models.

RESULTS

In this subset of the EMMA Study, we evaluated 164 (85.9%) patients with ischemic stroke and 27 (14.1%) with HS. Among these, overall incidence of MDD was 25.1% during 1 year of follow-up, regardless stroke subtype. The peak rate of major depression postacute event was beyond 1 month. We observed a lower survival rate among individuals who developed poststroke MDD than among those who did not develop this condition after 1 year of follow-up (85.4% versus 96.5%, log rank P = .006). After multiple analysis, we kept a higher risk of all-cause mortality among those who developed MDD compared to participants without MDD (hazard ratio = 4.60, 95% confidence interval = 1.36-15.55, P = .01).

CONCLUSION

Our findings suggest that incident MDD is a potential marker of poor prognosis 1 year after stroke.

The intrinsic geometry of the human brain connectome

This paper describes novel methods for constructing the intrinsic geometry of the human brain connectome using dimensionality-reduction techniques. We posit that the high-dimensional, complex geometry that represents this intrinsic topology can be mathematically embedded into lower dimensions using coupling patterns encoded in the corresponding brain connectivity graphs. We tested both linear and nonlinear dimensionality-reduction techniques using the diffusion-weighted structural connectome data acquired from a sample of healthy subjects. Results supported the nonlinearity of brain connectivity data, as linear reduction techniques such as the multidimensional scaling yielded inferior lower-dimensional embeddings. To further validate our results, we demonstrated that for tractography-derived structural connectome more influential regions such as rich-club members of the brain are more centrally mapped or embedded. Further, abnormal brain connectivity can be visually understood by inspecting the altered geometry of these three-dimensional (3D) embeddings that represent the topology of the human brain, as illustrated using simulated lesion studies of both targeted and random removal. Last, in order to visualize brain's intrinsic topology we have developed software that is compatible with virtual reality technologies, thus allowing researchers to collaboratively and interactively explore and manipulate brain connectome data.

Beyond neural cubism: promoting a multidimensional view of brain disorders by enhancing the integration of neurology and psychiatry in education

Cubism was an influential early-20th-century art movement characterized by angular, disjointed imagery. The two-dimensional appearance of Cubist figures and objects is created through juxtaposition of angles. The authors posit that the constrained perspectives found in Cubism may also be found in the clinical classification of brain disorders. Neurological disorders are often separated from psychiatric disorders as if they stemmed from different organ systems. Maintaining two isolated clinical disciplines fractionalizes the brain in the same way that Pablo Picasso fractionalized figures and objects in his Cubist art. This Neural Cubism perpetuates a clinical divide that does not reflect the scope and depth of neuroscience. All brain disorders are complex and multidimensional, with aberrant circuitry and resultant psychopharmacology manifesting as altered behavior, affect, mood, or cognition. Trainees should receive a multidimensional education based on modern neuroscience, not a partial education based on clinical precedent. The authors briefly outline the rationale for increasing the integration of neurology and psychiatry and discuss a nested model with which clinical neuroscientists (neurologists and psychiatrists) can approach and treat brain disorders.

Basal ganglia circuit loops, dopamine and motivation: A review and enquiry

Dopamine neurons located in the midbrain play a role in motivation that regulates approach behavior (approach motivation). In addition, activation and inactivation of dopamine neurons regulate mood and induce reward and aversion, respectively. Accumulating evidence suggests that such motivational role of dopamine neurons is not limited to those located in the ventral tegmental area, but also in the substantia nigra. The present paper reviews previous rodent work concerning dopamine's role in approach motivation and the connectivity of dopamine neurons, and proposes two working models: One concerns the relationship between extracellular dopamine concentration and approach motivation. High, moderate and low concentrations of extracellular dopamine induce euphoric, seeking and aversive states, respectively. The other concerns circuit loops involving the cerebral cortex, basal ganglia, thalamus, epithalamus, and midbrain through which dopaminergic activity alters approach motivation. These models should help to generate hypothesis-driven research and provide insights for understanding altered states associated with drugs of abuse and affective disorders.

Psychological factors determine depressive symptomatology after stroke

OBJECTIVE

To identify psychological factors related to poststroke depressive symptoms.

DESIGN

Cross-sectional study, with patients assessed at 2 months poststroke.

SETTING

Patients with stroke from 6 general hospitals.

PARTICIPANTS

Stroke patients (N=344; mean age ± SD, 66.9±12.3y).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The presence of clinical depressive symptoms was determined with the depression subscale of the Hospital Anxiety and Depression Scale 2 months poststroke. Psychological factors assessed were extraversion, neuroticism, optimism, pessimism, self-efficacy, helplessness, acceptance, perceiving benefits, proactive coping, and passive coping.

RESULTS

Bivariate correlations and multivariate backward logistic regression were used to analyze associations between psychological factors and poststroke depressive symptoms, accounting for demographic and stroke-related factors. More neuroticism, pessimism, passive coping, and helplessness, and less extraversion, optimism, self-efficacy, acceptance, perceived benefits, and proactive coping were bivariately associated with the presence of depressive symptoms. Multivariate logistic regression analysis showed that more helplessness (odds ratio [OR]=1.17) and passive coping (OR=1.19) and less acceptance (OR=.89) and perceived benefits (OR=.89) were independently significantly associated with the presence of poststroke depressive symptoms (Nagelkerke R(2)=.49).

CONCLUSIONS

We found a relationship between psychological variables and the presence of depressive symptoms 2 months poststroke. It is important to take these factors into account during poststroke rehabilitation.

The association of post-stroke anhedonia with salivary cortisol levels and stroke lesion in hippocampal/parahippocampal region

BACKGROUND

Anhedonia constitutes a coherent construct, with neural correlates and negative clinical impact, independent of depression. However, little is known about the neural correlates of anhedonia in stroke patients. In this study, we investigated the association of post-stroke anhedonia with salivary cortisol levels and stroke location and volume.

PATIENTS AND METHODS

A psychiatrist administered the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition to identify anhedonia in 36 inpatients, without previous depression, consecutively admitted in a neurology clinic in the first month after a first-ever ischemic stroke. Salivary cortisol levels were assessed in the morning, evening, and after a dexamethasone suppression test. We used magnetic resonance imaging and a semi-automated brain morphometry method to assess stroke location, and the MRIcro program according to the Brodmann Map to calculate the lesion volume.

RESULTS

Patients with anhedonia had significantly larger diurnal variation (P-value =0.017) and higher morning levels of salivary cortisol (1,671.9±604.0 ng/dL versus 1,103.9±821.9 ng/dL; P-value =0.022), and greater stroke lesions in the parahippocampal gyrus (Brodmann area 36) compared to those without anhedonia (10.14 voxels; standard deviation ±17.72 versus 0.86 voxels; standard deviation ±4.64; P-value =0.027). The volume of lesion in the parahippocampal gyrus (Brodmann area 36) was associated with diurnal variation of salivary cortisol levels (rho=0.845; P-value =0.034) only in anhedonic patients.

CONCLUSION

Our findings suggest that anhedonia in stroke patients is associated with the volume of stroke lesion in the parahippocampal gyrus and with dysfunction of the hypothalamic-pituitary-adrenal axis.

Risk factors for poststroke depression: identification of inconsistencies based on a systematic review

OBJECTIVE

Depression after stroke or poststroke depression (PSD) has a negative impact on the rehabilitation process and the associated rehabilitation outcome. Consequently, defining risk factors for development of PSD is important. The relationship between stroke and depression is described extensively in the available literature, but the results are inconsistent. The aim of this systematic review is to outline conflicting evidence on risk factors for PSD.

METHODS

PubMed, Medline, and Web of Knowledge were searched using the keywords "stroke," "depression," and "risk factor" for articles published between January 01, 1995, and September 30, 2012. Additional articles were identified and obtained from a hand search in related articles and reference lists.

RESULTS

A total of 66 article abstracts were identified by the search strategy and 24 articles were eligible for inclusion based on predefined quality criteria. The methodology varies greatly between the various studies, which is probably responsible for major differences in risk factors for PSD reported in the literature. The most frequently cited risk factors for PSD in the literature are sex (female), history of depression, stroke severity, functional impairments or level of handicap, level of independence, and family and social support.

CONCLUSIONS

Many risk factors are investigated over the last 2 decades and large controversy exists concerning risk factors for development of PSD. These contradictions may largely be reduced to major differences in clinical data, study population, and methodology, which underline the need for more synchronized studies.

Microstructural abnormalities in white matter and their effect on depressive symptoms after stroke

The aim of the study was to investigate the existence of microstructural abnormalities in the white matter of the brain in stroke patients, as well as the relationship between these microstructural abnormalities and changes in depressive symptoms over 6 months. Participants were 29 acute ischemic stroke patients and 37 healthy control subjects. Depressive symptoms were assessed in all subjects using the Hamilton Rating Scale for Depression and the Zung Self-rating Depression Scale. Whole brain voxel-based analysis was used to compare diffusion tensor imaging measures of Fractional Anisotropy (FA) between the groups. Six-month follow-up examinations were conducted. Patients showed significantly lower white matter FA values in the left and right anterior limbs of the internal capsule, and 6 months after the stroke they showed significantly increased FA values in these regions. We found a significant negative correlation between the increased ratio of the FA values and the change in depression scale scores at 6-month follow-up. Regional white matter damage may reflect abnormalities in neuroanatomical pathways related to the pathophysiology of depression.

The relationship between frontal lobe lesions, course of post-stroke depression, and 1-year prognosis in patients with first-ever ischemic stroke

BACKGROUND AND PURPOSE

Most studies on post-stroke depression (PSD) have focused on a certain time point after stroke instead of the time course of PSD. The aim of this study was to determine the relationship between frontal lobe lesions, course of PSD over a year following the stroke onset, and the 1-year prognosis in patients with first-ever ischemic stroke.

METHODS

A total of 1067 patients from the prospective cohort study on the incidence and outcome of patients with post stroke depression in China who were diagnosed with first-ever ischemic stroke and attended 4 follow-up visits at 14±2 days, 3 months, 6 months, and 1 year after stroke onset, were enrolled in the study. PSD was diagnosed according to DSM-IV. The course of PSD was divided into the following two categories: persistent/recurrent depression and no/transient depression. Patients with any ischemic lesion responsible for the indexed stroke event located in the frontal lobe were defined as patients with frontal lobe lesions. Modified Rankin Scale (mRS) ≥2 at 1-year was considered to be poor prognosis.

RESULTS

There were 109 patients with and 958 patients without frontal lobe lesions that formed the frontal lobe (FL) and no-frontal lobe (NFL) groups, respectively. After adjusting for confounding variables, frontal lobe lesion was significantly associated with persistent/recurrent PSD (OR 2.025, 95%CI 1.039-3.949). Overall, 32.7% of patients in the FL group had poor prognosis at 1- year compared with 22.7% in the NFL group (P = 0.021). Compared with no/transient depression, persistent/recurrent depression was found to be an independent predictor of poor prognosis at 1-year both in FL and NFL groups.

CONCLUSIONS

Long-term and periodical screening, evaluation and treatment are needed for PSD after the onset of ischemic stroke, particularly for patients with frontal lobe infarction.

Imaging predictors of poststroke depression: methodological factors in voxel-based analysis

OBJECTIVE

The purpose of this study was to explore the relationship between lesion location and poststroke depression using statistical parametric mapping.

METHODS

First episode patients with stroke were assessed within 12 days and at 1-month poststroke. Patients with an a priori defined cut-off score of 11 on the Hospital Anxiety and Depression Scale (HADS) at follow-up were further assessed using the Mini-International Neuropsychiatric Interview (MINI) to confirm a clinical diagnosis of major or minor depression in accordance with Diagnostic and Statistical Manual-IV (DSM-IV) inclusion criteria. Participants were included if they were aged 18-85 years, proficient in English and eligible for MRI. Patients were excluded if they had a confounding diagnosis such as major depressive disorder at the time of admission, a neurodegenerative disease, epilepsy or an imminently life-threatening comorbid illness, subarachnoid or subdural stroke, a second episode of stroke before follow-up and/or a serious impairment of consciousness or language. Infarcts observed on MRI scans were manually segmented into binary images, linearly registered into a common stereotaxic coordinate space. Using statistical parametric mapping, we compared infarct patterns in patients with stroke with and without depression.

RESULTS

27% (15/55 patients) met criteria for depression at follow-up. Mean infarct volume was 19±53 mL and National Institute of Health Stroke Scale (NIHSS) at Time 1 (within 12 days of stroke) was 4±4, indicating a sample of mild strokes. No voxels or clusters were significant after a multiple comparison correction was applied (p>0.05). Examination of infarct maps showed that there was minimal overlap of infarct location between patients, thus invalidating the voxel comparison analysis.

CONCLUSIONS

This study provided inconclusive evidence for the association between infarcts in a specific region and poststroke depression.

The neurobiological pathogenesis of poststroke depression

Poststroke depression (PSD) is an important consequence after stroke, with negative impact on stroke outcome. The pathogenesis of PSD is complicated, with some special neurobiological mechanism, which mainly involves neuroanatomical, neuron, and biochemical factors and neurogenesis which interact in complex ways. Abundant studies suggested that large lesions in critical areas such as left frontal lobe and basal ganglia or accumulation of silent cerebral lesions might interrupt the pathways of monoamines or relevant pathways of mood control, thus leading to depression. Activation of immune system after stroke produces more cytokines which increase glutamate excitotoxicity, results in more cell deaths of critical areas and enlargement of infarctions, and, together with hypercortisolism induced by stress or inflammation after stroke which could decrease intracellular serotonin transporters, might be the key biochemical change of PSD. The interaction among cytokines, glucocorticoid, and neurotrophin results in the decrease of hippocampal neurogenesis which has been proved to be important for mood control and pharmaceutical effect of selective serotonin reuptake inhibitors and might be another promising pathway to understand the pathogenesis of PSD. In order to reduce the prevalence of PSD and improve the outcome of stroke, more relevant studies are still required to clarify the pathogenesis of PSD.

Peril and pleasure: an rdoc-inspired examination of threat responses and reward processing in anxiety and depression

As a step toward addressing limitations in the current psychiatric diagnostic system, the National Institute of Mental Health recently developed the Research Domain Criteria (RDoC) to stimulate integrative research-spanning self-report, behavior, neural circuitry, and molecular/genetic mechanisms-on core psychological processes implicated in mental illness. Here, we use the RDoC conceptualization to review research on threat responses, reward processing, and their interaction. The first section of the manuscript highlights the pivotal role of exaggerated threat responses-mediated by circuits connecting the frontal cortex, amygdala, and midbrain-in anxiety, and reviews data indicating that genotypic variation in the serotonin system is associated with hyperactivity in this circuitry, which elevates the risk for anxiety and mood disorders. In the second section, we describe mounting evidence linking anhedonic behavior to deficits in psychological functions that rely heavily on dopamine signaling, especially cost/benefit decision making and reward learning. The third section covers recent studies that document negative effects of acute threats and chronic stress on reward responses in humans. The mechanisms underlying such effects are unclear, but the fourth section reviews new optogenetic data in rodents indicating that GABAergic inhibition of midbrain dopamine neurons, driven by activation of the habenula, may play a fundamental role in stress-induced anhedonia. In addition to its basic scientific value, a better understanding of interactions between the neural systems that mediate threat and reward responses may offer relief from the burdensome condition of anxious depression.

Off-label prescription of quetiapine in psychiatric disorders

This article reviews the off-label prescription of quetiapine in the treatment of a broad range of psychiatric disorders including obsessive-compulsive disorder, post-traumatic stress disorder, personality disorder, substance abuse, bipolar disorder (now US FDA approved), anxiety and depression. The article highlights the primary reliance on selective serotonin reuptake inhibitors (SSRIs) in the treatment of these disorders (cf bipolar disorder) and the high percentage of patients (30-60%) that do not respond to SSRIs. The studies suggest that low-dose quetiapine shows good tolerability and efficacy in patients diagnosed with these disorders, particularly in the case of treatment-resistant patients that do not respond to primary treatments including SSRIs and cognitive-behavioral therapy. Quetiapine generally appears to be very effective in trauma-related conditions by improving autonomic stability, and decreasing the stress and anxiety response that arises due to specific fears or triggers. Quetiapine also appears to be particularly useful for normalizing obsessions and compulsions, and improving low mood, irritability and aggressiveness. A greater understanding of the pharmacology of drug alternatives and the neurobiology of psychiatric disorders is required to permit a more personalized medicine approach.

STroke imAging pRevention and Treatment (START): A Longitudinal Stroke Cohort Study: Clinical Trials Protocol

Rationale

Stroke and poststroke depression are common and have a profound and ongoing impact on an individual's quality of life. However, reliable biological correlates of poststroke depression and functional outcome have not been well established in humans.

Aims

Our aim is to identify biological factors, molecular and imaging, associated with poststroke depression and recovery that may be used to guide more targeted interventions.

Design

In a longitudinal cohort study of 200 stroke survivors, the START – STroke imAging pRevention and Treatment cohort, we will examine the relationship between gene expression, regulator proteins, depression, and functional outcome. Stroke survivors will be investigated at baseline, 24 h, three-days, three-months, and 12 months poststroke for blood-based biological associates and at days 3–7, three-months, and 12 months for depression and functional outcomes. A sub-group ( n = 100), the PrePARE: Prediction and Prevention to Achieve optimal Recovery Endpoints after stroke cohort, will also be investigated for functional and structural changes in putative depression-related brain networks and for additional cognition and activity participation outcomes. Stroke severity, diet, and lifestyle factors that may influence depression will be monitored. The impact of depression on stroke outcomes and participation in previous life activities will be quantified.

Study Outcomes

Clinical significance lies in the identification of biological factors associated with functional outcome to guide prevention and inform personalized and targeted treatments. Evidence of associations between depression, gene expression and regulator proteins, functional and structural brain changes, lifestyle and functional outcome will provide new insights for mechanism-based models of poststroke depression.

Depression uncouples brain hate circuit

It is increasingly recognized that we need a better understanding of how mental disorders such as depression alter the brain's functional connections to improve both early diagnosis and therapy. A new holistic approach has been used to investigate functional connectivity changes in the brains of patients suffering from major depression using resting-state functional magnetic resonance imaging (fMRI) data. A canonical template of connectivity in 90 different brain regions was constructed from healthy control subjects and this identified a six-community structure with each network corresponding to a different functional system. This template was compared with functional networks derived from fMRI scans of both first-episode and longer-term, drug resistant, patients suffering from severe depression. The greatest change in both groups of depressed patients was uncoupling of the so-called 'hate circuit' involving the superior frontal gyrus, insula and putamen. Other major changes occurred in circuits related to risk and action responses, reward and emotion, attention and memory processing. A voxel-based morphometry analysis was also carried out but this revealed no evidence in the depressed patients for altered gray or white matter densities in the regions showing altered functional connectivity. This is the first evidence for the involvement of the 'hate circuit' in depression and suggests a potential reappraisal of the key neural circuitry involved. We have hypothesized that this may reflect reduced cognitive control over negative feelings toward both self and others.

States of mind: emotions, body feelings, and thoughts share distributed neural networks

Scientists have traditionally assumed that different kinds of mental states (e.g., fear, disgust, love, memory, planning, concentration, etc.) correspond to different psychological faculties that have domain-specific correlates in the brain. Yet, growing evidence points to the constructionist hypothesis that mental states emerge from the combination of domain-general psychological processes that map to large-scale distributed brain networks. In this paper, we report a novel study testing a constructionist model of the mind in which participants generated three kinds of mental states (emotions, body feelings, or thoughts) while we measured activity within large-scale distributed brain networks using fMRI. We examined the similarity and differences in the pattern of network activity across these three classes of mental states. Consistent with a constructionist hypothesis, a combination of large-scale distributed networks contributed to emotions, thoughts, and body feelings, although these mental states differed in the relative contribution of those networks. Implications for a constructionist functional architecture of diverse mental states are discussed.

Exofocal dopaminergic degeneration as antidepressant target in mouse model of poststroke depression

BACKGROUND

Although poststroke depression (PSD) is a frequent chronic complication of stroke with high relevance for outcome and survival, underlying pathomechanisms remain inadequately understood. This may be because suitable animal models are largely lacking and existing models are poorly characterized.

METHODS

Male 129/SV mice were subjected to 30-min middle cerebral artery occlusion (MCAo)/reperfusion and serial magnetic resonance imaging scans. A subset of animals received selective serotonin reuptake inhibitor citalopram starting 7 days after MCAo. Behavioral assessment was performed at 14 weeks. To identify biological correlates of PSD, we quantified corticosterone levels in serum and brain-derived neurotrophic factor levels in brain. The integrity of the mesolimbic dopaminergic system was assessed using tyrosine hydroxylase and dynorphin in situ hybridizations as well as dopamine transporter autoradiography.

RESULTS

Left, but not right, MCAo, elicited anhedonia and increased anxiety and despair. This depression-like syndrome was associated with alterations in the mesolimbic reward system. MCAo resulted in delayed degeneration of dopaminergic neurons in ipsilateral midbrain, which was accompanied by reduced dopamine concentrations and decreased levels of dopamine transporter density along with increased brain-derived neurotrophic factor protein levels in ischemic striatum and increased dynorphin messenger RNA expression in nucleus accumbens. Chronic antidepressant treatment initiated as late as 7 days after stroke reversed the behavioral phenotype, prevented degeneration of dopaminergic midbrain neurons, and attenuated striatal atrophy at 4 months.

CONCLUSIONS

Our results highlight the importance of the dopaminergic system for the development of PSD. Prevention of secondary neurodegeneration by antidepressants may provide a novel target for subacute stroke therapy.

A prospective cohort study of lesion location and its relation to post-stroke depression among Chinese patients

BACKGROUND

Post-stroke depression (PSD) is a common consequence of stroke that negatively interferes with the rehabilitation outcome in patients. It remains unclear what relationship exists between the site and size of brain infarcts and the development of PSD and the risk factors for PSD. We conducted a MRI-based cohort study to examine the radiological correlations for PSD in Chinese patients with ischemic stroke.

METHODS

Our study included 163 patients with acute ischemic stroke. The diagnosis of PSD was made with World Health Organization Composite International Diagnostic Interview (WHO-CIDI), which is based on Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) during a follow-up exam at 3-month post stroke. The demographic, clinical, and detailed radiological variables (e.g., lesion location, and degree of white matter lesions) were also examined.

RESULTS

The univariate analyses suggested that the frequency of multiple acute infarcts, the total number and volume of acute infarcts were higher in the PSD group than those in the non-PSD group. In particular, PSD patients showed higher rates of infarcts in cortical-subcortical area of the frontal and temporal lobe as well as in internal capsule (including genu, anterior and posterior limb). The multivariate analysis suggested that independent radiological risk factors for PSD may include the presence of multiple acute infarcts, the infarct affecting either side of posterior limb of internal capsule, genu of internal capsule, and cortical-subcortical areas in the temporal lobe.

CONCLUSION

Our study on ischemic stroke patients suggested that certain neuroanatomical factors (i.e., lesions at posterior limb and genu of internal capsule and cortical-subcortical area of the temporal lobe, as well as the presence of multiple acute infarcts) may correlate with the PSD development.

Stroke lesion in cortical neural circuits and post-stroke incidence of major depressive episode: a 4-month prospective study

OBJECTIVE

Little is known about the relevance of lesion in neural circuits reported to be associated with major depressive disorder. We investigated the association between lesion stroke size in the limbic-cortical-striatal-pallidal-thalamic (LCSPT) circuit and incidence of major depressive episode (MDE).

METHODS

We enrolled 68 patients with first-ever ischemic stroke and no history of major depressive disorder. Neurological and psychiatric examinations were performed at three time-points. We diagnosed major depressive episode, following DSM-IV criteria. Lesion location and volume were determined with magnetic resonance imaging, using a semi-automated method based on the Brodmann Cytoarchitectonic Atlas.

RESULTS

Twenty-one patients (31%) experienced major depressive episode. Larger lesions in the left cortical regions of the LCSPT circuit (3,760 vs. 660 mm3; P = 0.004) were associated with higher incidence of MDE. Secondary analyses revealed that major depressive episode was associated with larger lesions in areas of the medial prefrontal cortex including the ventral (BA24) and dorsal anterior cingulate cortex (BA32) and subgenual cortex (BA25); and also the subiculum (BA28/36) and amygdala (BA34).

CONCLUSIONS

Our findings indicate that depression due to stroke is aetiologically related to the disruption of the left LCSPT circuit and support the relevance of the medial prefrontal cortex dysfunction in the pathophysiology of depression.

Association of frontal subcortical circuits infarcts in poststroke depression: a magnetic resonance imaging study of 591 Chinese patients with ischemic stroke

Despite extensive research into poststroke depression (PSD), the role played by lesion location in the pathogenesis of PSD remains uncertain. The aim of this study was to estimate the magnetic resonance imaging (MRI) correlates of PSD in Chinese patients with first or recurrent stroke. A total of 591 patients with acute ischemic stroke admitted to the acute stroke unit of a university-affiliated regional hospital in Hong Kong were recruited. A psychiatrist assessed all the patients 3 months after the stroke. The psychiatrist used the Structured Clinical Interview for Diagnostic and Statistical Manual, fourth edition (DSM-IV) to confirm whether the patients met the criteria of a depressive disorder. In addition, a host of demographic, clinical, and radiological variables were examined. A tota; of 475 and 116 patients had first and recurrent strokes, respectively. In all, 75 (12.7%) patients received a diagnosis of PSD. In univariate analysis of the MRI findings, the presence of infarcts in the frontal subcortical circuits ([FSC], 66.7% vs 53.3%) was significantly associated with PSD (P = .03) compared to the patients without PSD. The FSC infarct-PSD association remained significant (odds ratio = 2.6) in subsequent logistic regression analysis after adjusting for gender, history of depression, neurological impairment, level of social support, and major life events. In conclusion, FSC infarcts are independent predictors of PSD. Further work is needed to clarify whether these infarcts have an impact on the clinical presentation, treatment responses, and prognosis of PSD.

Post-stroke depression: can prediction help prevention?

Depression is common after stroke. Post-stroke depression (PSD) is an independent predictor of poor long-term functional outcome following stroke. PSD has been associated with poor social and rehabilitation outcomes, cognitive impairment and increased mortality. Prevalence varies widely between studies because of differences in patient selection, time, evaluation methods and diagnostic criteria. Approximately a third of stroke survivors may suffer from PSD. Potential confounders include anosognosia, apathy and emotional lability. The identification of risk factors is important to prevent and detect PSD early, and provide appropriate interventions. PSD may be associated with restriction in social activities and dependence in activities of daily living in the chronic phase of stroke. Pharmacologic and rehabilitation strategies are needed to treat PSD. More evidence is required before recommendations can be made about the routine use of antidepressants to prevent PSD.