Conjugacy and rigidity for nonpositively curved manifolds of higher rank

AbstractLet M and N be compact Riemannian manifolds with sectional curvature K ⩽ 0 such that M has dimension ⩾ 3 and rank ⩾ 2. If there exists a C0 conjugacy F between the geodesic flows of the unit tangent bundles of M and N, then there exists an isometry G: M → N that induces the same isomorphism as F between the fundamental groups of M and N

Development and validation of a multimodal neuroimaging biomarker for electroconvulsive therapy outcome in depression: A multicenter machine learning analysis

Background Electroconvulsive therapy (ECT) is the most effective intervention for patients with treatment resistant depression. A clinical decision support tool could guide patient selection to improve the overall response rate and avoid ineffective treatments with adverse effects. Initial small-scale, monocenter studies indicate that both structural magnetic resonance imaging (sMRI) and functional MRI (fMRI) biomarkers may predict ECT outcome, but it is not known whether those results can generalize to data from other centers. The objective of this study was to develop and validate neuroimaging biomarkers for ECT outcome in a multicenter setting. Methods Multimodal data (i.e. clinical, sMRI and resting-state fMRI) were collected from seven centers of the Global ECT-MRI Research Collaboration (GEMRIC). We used data from 189 depressed patients to evaluate which data modalities or combinations thereof could provide the best predictions for treatment remission (HAM-D score ⩽7) using a support vector machine classifier. Results Remission classification using a combination of gray matter volume and functional connectivity led to good performing models with average 0.82–0.83 area under the curve (AUC) when trained and tested on samples coming from the three largest centers (N = 109), and remained acceptable when validated using leave-one-site-out cross-validation (0.70–0.73 AUC). Conclusions These results show that multimodal neuroimaging data can be used to predict remission with ECT for individual patients across different treatment centers, despite significant variability in clinical characteristics across centers. Future development of a clinical decision support tool applying these biomarkers may be feasible.publishedVersio

Effective resting-state connectivity in severe unipolar depression before and after electroconvulsive therapy

BACKGROUND: Electroconvulsive therapy (ECT) is one of the most effective treatments for severe depressive disorders. A recent multi-center study found no consistent changes in correlation-based (undirected) resting-state connectivity after ECT. Effective (directed) connectivity may provide more insight into the working mechanism of ECT. OBJECTIVE: We investigated whether there are consistent changes in effective resting-state connectivity. METHODS: This multi-center study included data from 189 patients suffering from severe unipolar depression and 59 healthy control participants. Longitudinal data were available for 81 patients and 24 healthy controls. We used dynamic causal modeling for resting-state functional magnetic resonance imaging to determine effective connectivity in the default mode, salience and central executive networks before and after a course of ECT. Bayesian general linear models were used to examine differences in baseline and longitudinal effective connectivity effects associated with ECT and its effectiveness. RESULTS: Compared to controls, depressed patients showed many differences in effective connectivity at baseline, which varied according to the presence of psychotic features and later treatment outcome. Additionally, effective connectivity changed after ECT, which was related to ECT effectiveness. Notably, treatment effectiveness was associated with decreasing and increasing effective connectivity from the posterior default mode network to the left and right insula, respectively. No effects were found using correlation-based (undirected) connectivity. CONCLUSIONS: A beneficial response to ECT may depend on how brain regions influence each other in networks important for emotion and cognition. These findings further elucidate the working mechanisms of ECT and may provide directions for future non-invasive brain stimulation research

Effective resting-state connectivity in severe unipolar depression before and after electroconvulsive therapy

Background Electroconvulsive therapy (ECT) is one of the most effective treatments for severe depressive disorders. A recent multi-center study found no consistent changes in correlation-based (undirected) resting-state connectivity after ECT. Effective (directed) connectivity may provide more insight into the working mechanism of ECT. Objective We investigated whether there are consistent changes in effective resting-state connectivity. Methods This multi-center study included data from 189 patients suffering from severe unipolar depression and 59 healthy control participants. Longitudinal data were available for 81 patients and 24 healthy controls. We used dynamic causal modeling for resting-state functional magnetic resonance imaging to determine effective connectivity in the default mode, salience and central executive networks before and after a course of ECT. Bayesian general linear models were used to examine differences in baseline and longitudinal effective connectivity effects associated with ECT and its effectiveness. Results Compared to controls, depressed patients showed many differences in effective connectivity at baseline, which varied according to the presence of psychotic features and later treatment outcome. Additionally, effective connectivity changed after ECT, which was related to ECT effectiveness. Notably, treatment effectiveness was associated with decreasing and increasing effective connectivity from the posterior default mode network to the left and right insula, respectively. No effects were found using correlation-based (undirected) connectivity. Conclusions A beneficial response to ECT may depend on how brain regions influence each other in networks important for emotion and cognition. These findings further elucidate the working mechanisms of ECT and may provide directions for future non-invasive brain stimulation research.publishedVersio

Are people living with HIV less productive at work?

Health problems may cause decreased productivity among working people. It is unclear if this also applies for people living with HIV (PLWH). This cross-sectional study compares data of PLWH of one of the main HIV treatment centres in the Netherlands (n = 298) to data of the general working population from a previously conducted study (n = 986). We investigate whether productivity at work differs between these groups. The questionnaires used in these studies contained a core of identical questions regarding productivity losses, in the form of absenteeism and presenteeism, over a four-week period and a variety of baseline characteristics, including health status measured with EQ-5D. For PLWH additional clinical data were collected from patient records. From the data, descriptive statistics were computed to characterize the samples. Pearson correlations were used to explore significant associations of productivity with baseline characteristics. A two-part model was used to evaluate both the occurrence and of size of productivity losses in working PLWH and an aggregated sample of PLWH and the general population. It was observed that, on average, total productivity losses do not differ significantly between working PWLH and th

Interrogating Associations Between Polygenic Liabilities and Electroconvulsive Therapy Effectiveness

Background: Electroconvulsive therapy (ECT) is the most effective treatment for severe major depressive episodes (MDEs). Nonetheless, firmly established associations between ECT outcomes and biological variables are currently lacking. Polygenic risk scores (PRSs) carry clinical potential, but associations with treatment response in psychiatry are seldom reported. Here, we examined whether PRSs for major depressive disorder, schizophrenia (SCZ), cross-disorder, and pharmacological antidepressant response are associated with ECT effectiveness. Methods: A total of 288 patients with MDE from 3 countries were included. The main outcome was a change in the 17-item Hamilton Depression Rating Scale scores from before to after ECT treatment. Secondary outcomes were response and remission. Regression analyses with PRSs as independent variables and several covariates were performed. Explained variance (R 2) at the optimal p-value threshold is reported. Results: In the 266 subjects passing quality control, the PRS-SCZ was positively associated with a larger Hamilton Depression Rating Scale decrease in linear regression (optimal p-value threshold = .05, R 2 = 6.94%, p < .0001), which was consistent across countries: Ireland (R 2 = 8.18%, p = .0013), Belgium (R 2 = 6.83%, p = .016), and the Netherlands (R 2 = 7.92%, p = .0077). The PRS-SCZ was also positively associated with remission (R 2 = 4.63%, p = .0018). Sensitivity and subgroup analyses, including in MDE without psychotic features (R 2 = 4.42%, p = .0024) and unipolar MDE only (R 2 = 9.08%, p < .0001), confirmed the results. The other PRSs were not associated with a change in the Hamilton Depression Rating Scale score at the predefined Bonferroni-corrected significance threshold. Conclusions: A linear association between PRS-SCZ and ECT outcome was uncovered. Although it is too early to adopt PRSs in ECT clinical decision making, these findings strengthen the positioning of PRS-SCZ as relevant to treatment response in psychiatry

H.J. Luijendijk. Vascular heart and brain disease and incident late-life depression.

bespreking proefschrift H.J. (Dika) Luijendijk. Vascular heart and brain disease and incident late-life depression Ongeveer 15 tot 20 procent van de mensen ontwikkelt tenminste één keer in zijn leven een depressie. Depressie bij ouderen is een van de belangrijkste gezondheidsproblemen van de 21ste eeuw in termen van ziekte, sterfte en het gebruik van de gezondheidszorg. Voor zowel onderzoekers als praktiserende clinici is het belangrijk om meer te weten over de factoren die bijdragen aan het ontwikkelen van een depressie bij ouderen

Implementing an outreaching, preference-led stepped care intervention programme to reduce late life depressive symptoms: results of a mixed-methods study

Contains fulltext : 138248.pdf (publisher's version ) (Open Access)BACKGROUND: Depressive symptoms are highly prevalent in old age, but they remain mostly untreated. Several clinical trials have shown promising results in preventing or reducing depressive symptoms. However, it is not clear how robust these effects are in the real world of day-to-day care. Therefore, we have implemented the 'Lust for Life' programme, which significantly reduced depressive symptoms in community-dwelling older adults in the first three months after implementation. This mixed-methods study was conducted alongside the trial to develop a contextualised understanding of factors affecting the implementation. METHODS: A total of 263 persons of 65 years and older with depressive symptoms were recruited from 18 general practices and home care organizations in the Netherlands. We used qualitative data (in-depth interviews and focus group discussions with participants with depressive symptoms and healthcare professionals) as well as quantitative data (longitudinal data on the severity of depressive symptoms) to explore hindering and facilitating factors to the implementation of the 'Lust for Life' programme. RESULTS: The uptake of the routine screening was poor and imposed significant burdens on participants and healthcare professionals, and drop-out rates were high. Participants' perceived mental problems and need for care played a key role in their decision to participate in the programme and to step up to consequent interventions. Older people preferred interventions that focused on interpersonal contact. The programme was only effective when delivered by mental healthcare nurses, compared to home care nurses with limited experience in providing mental healthcare. CONCLUSIONS: The intervention programme was effective in reducing depressive symptoms, and valuable lessons can be learned from this implementation trial. Given the low uptake and high investment, we advise against routine screening for depressive symptoms in general healthcare. Further, agreement between the participant and healthcare professional on perceived need for care and intervention is vital. Rather than providing a stepped care intervention programme, we showed that offering only one single preference-led intervention is effective. Lastly, since the provision of the interventions seems to ask for specific skills and experiences, it might require mental healthcare nurses to offer the programme. TRIAL REGISTRATION: Dutch trial register NTR2241