Are Bohmian trajectories real? On the dynamical mismatch between de Broglie-Bohm and classical dynamics in semiclassical systems

The de Broglie-Bohm interpretation of quantum mechanics aims to give a realist description of quantum phenomena in terms of the motion of point-like particles following well-defined trajectories. This work is concerned by the de Broglie-Bohm account of the properties of semiclassical systems. Semiclassical systems are quantum systems that display the manifestation of classical trajectories: the wavefunction and the observable properties of such systems depend on the trajectories of the classical counterpart of the quantum system. For example the quantum properties have a regular or disordered aspect depending on whether the underlying classical system has regular or chaotic dynamics. In contrast, Bohmian trajectories in semiclassical systems have little in common with the trajectories of the classical counterpart, creating a dynamical mismatch relative to the quantum-classical correspondence visible in these systems. Our aim is to describe this mismatch (explicit illustrations are given), explain its origin, and examine some of the consequences on the status of Bohmian trajectories in semiclassical systems. We argue in particular that semiclassical systems put stronger constraints on the empirical acceptability and plausibility of Bohmian trajectories because the usual arguments given to dismiss the mismatch between the classical and the de Broglie-Bohm motions are weakened by the occurrence of classical trajectories in the quantum wavefunction of such systems.Comment: Figures downgraded to low resolution. V2:Minor change

A qualitative study of the views of residents with dementia, their relatives and staff about work practice in long-term care settings

Background: Most people living in 24-hour care settings have dementia, and little is known about what makes long-term care a positive experience for them.Method: This carer-led qualitative study examined working practices in 24-hour long-term care-settings, including hospitals, nursing and residential homes, with the aim of finding out and making recommendations about such settings. Using semi-structured interviews, managers, nurses and care assistants were asked about work practices, such as how they coped with difficult behavior, about shifts, staffing levels, staff retention and training. Relatives of residents with dementia were asked about their role and perceptions of the care provided, and residents were asked for their opinions of their care.Results: Staff reported that residents presented with increasingly challenging behavior compared to the past, and that sometimes staffing levels and skills were inadequate. Of all the settings, hospitals had the most problems with staffing levels and retention, staff-relative relationships and staff support systems. Relatives saw their own role as positive. People with dementia of varying severity could usefully evaluate some of the services they received.Discussion: Dementia-specific training and education of staff in all long-term care-settings, including induction, should address the management of problem behavior in dementia and thereby improve staff fulfilment and relatives' satisfaction. The long-stay hospital may not be appropriate as a "home for life" for those with dementia, and we recommend that long-stay care settings should be able to cater flexibly for a range of resident needs

Life after caring: the post-caring experiences of former carers

This qualitative study was informed by grounded theory and data were gathered primarily through semi-structured in-depth interviews with thirty-seven theoretically sampled former carers. They were all white British, lived in the East Midlands and were predominately over sixty (68 per cent) and female (70 per cent). With the exception of one, all had cared for a close relative, 65 per cent having cared for a partner/spouse. Most of their dependants were older adults and each case the cessation of caring had coincided with the death of the dependant. The findings showed that post-caring life for the interviewees had an identifiable trajectory with three phases—the ‘post-caring void’, ‘closing down “the caring time” and ‘constructing life post-caring’. Each of these phases involved a distinct set of experiences. In addition, the study established that 70 per cent of those in the sample had cared more than once. Thus, two new concepts—’the post-caring trajectory’ and the ‘serial carer’— were developed to reflect these findings. Suggestions are made about ways in which policy, practice and further research can be developed in order to ensure there is effective provision for those who have ceased caring

Implementation of START (STrAtegies for RelaTives) for dementia carers in the third sector: Widening access to evidence-based interventions

Family members remain the main care providers for the increasing numbers of people with dementia, and often become depressed or anxious. In an implementation research project, we aimed to widen access to Strategies for RelaTives (START), a clinically and cost-effective intervention for the mental health of family carers, by laying the foundations for its implementation in the third sector. We used the integrated Promoting Action on Research Implementation in Health Services (i-PARIHS) framework to guide implementation of START, a manual-based, individually-delivered, multicomponent eight-session coping strategy intervention. We interviewed a maximum variation sample of twenty-seven stakeholders from the English Alzheimer's Society (AS), about possible difficulties in management, training, and delivery of START. We trained and supervised three AS dementia support workers in different locations, to each deliver START to three family carers. Two researchers independently coded pre-intervention interviews for themes. We assessed intervention feasibility through monitoring delivery fidelity, rating audio-recordings from 1-5 (5 being high) and interviewing facilitators, family carers and AS managers about their experiences. We assessed effectiveness on family carers' mental health using the Hospital Anxiety and Depression Scale (HADS) before and after receiving START (scores 0-42). We changed START's format by reflecting carer diversity more and increasing carer stories prominence, but core content or delivery processes were unchanged. All carers received START and attended every session. The mean fidelity score was 4.2. Mean HADS-total score reduced from baseline 18.4 (standard deviation 7.4) to follow-up 15.8 (9.7). Six (67%) carers scored as clinically depressed on baseline HADS and 2 (22%) at follow-up. Facilitators and carers rated START positively. Appropriately experienced third sector workers can be trained and supervised to deliver START and it remains effective. This has the potential for widened access at scale

Cost-effectiveness analyses for mirtazapine and sertraline in dementia: randomised controlled trial

BACKGROUND Depression is a common and costly comorbidity in dementia. There are very few data on the cost-effectiveness of antidepressants for depression in dementia and their effects on carer outcomes. AIMS To evaluate the cost-effectiveness of sertraline and mirtazapine compared with placebo for depression in dementia. METHOD A pragmatic, multicentre, randomised placebo-controlled trial with a parallel cost-effectiveness analysis (trial registration: ISRCTN88882979 and EudraCT 2006-000105-38). The primary cost-effectiveness analysis compared differences in treatment costs for patients receiving sertraline, mirtazapine or placebo with differences in effectiveness measured by the primary outcome, total Cornell Scale for Depression in Dementia (CSDD) score, over two time periods: 0-13 weeks and 0-39 weeks. The secondary evaluation was a cost-utility analysis using quality-adjusted life years (QALYs) computed from the Euro-Qual (EQ-5D) and societal weights over those same periods. RESULTS There were 339 participants randomised and 326 with costs data (111 placebo, 107 sertraline, 108 mirtazapine). For the primary outcome, decrease in depression, mirtazapine and sertraline were not cost-effective compared with placebo. However, examining secondary outcomes, the time spent by unpaid carers caring for participants in the mirtazapine group was almost half that for patients receiving placebo (6.74 v. 12.27 hours per week) or sertraline (6.74 v. 12.32 hours per week). Informal care costs over 39 weeks were £1510 and £1522 less for the mirtazapine group compared with placebo and sertraline respectively. CONCLUSIONS In terms of reducing depression, mirtazapine and sertraline were not cost-effective for treating depression in dementia. However, mirtazapine does appear likely to have been cost-effective if costing includes the impact on unpaid carers and with quality of life included in the outcome. Unpaid (family) carer costs were lower with mirtazapine than sertraline or placebo. This may have been mediated via the putative ability of mirtazapine to ameliorate sleep disturbances and anxiety. Given the priority and the potential value of supporting family carers of people with dementia, further research is warranted to investigate the potential of mirtazapine to help with behavioural and psychological symptoms in dementia and in supporting carers

Pilot cluster randomised trial of an evidence-based intervention to reduce avoidable hospital admissions in nursing home residents (Better Health in Residents of Care Homes with Nursing—BHiRCH-NH Study)

Objectives: To pilot a complex intervention to support healthcare and improve early detection and treatment for common health conditions experienced by nursing home (NH) residents. / Design: Pilot cluster randomised controlled trial. / Setting: 14 NHs (7 intervention, 7 control) in London and West Yorkshire. / Participants: NH residents, their family carers and staff. / Intervention: Complex intervention to support healthcare and improve early detection and treatment of urinary tract and respiratory infections, chronic heart failure and dehydration, comprising: (1) ‘Stop and Watch (S&W)’ early warning tool for changes in physical health, (2) condition-specific care pathway and (3) Situation, Background, Assessment and Recommendation tool to enhance communication with primary care. Implementation was supported by Practice Development Champions, a Practice Development Support Group and regular telephone coaching with external facilitators. / Outcome measures: Data on NH (quality ratings, size, ownership), residents, family carers and staff demographics during the month prior to intervention and subsequently, numbers of admissions, accident and emergency visits, and unscheduled general practitioner visits monthly for 6 months during intervention. We collected data on how the intervention was used, healthcare resource use and quality of life data for economic evaluation. We assessed recruitment and retention, and whether a full trial was warranted. / Results: We recruited 14 NHs, 148 staff, 95 family carers and 245 residents. We retained the majority of participants recruited (95%). 15% of residents had an unplanned hospital admission for one of the four study conditions. We were able to collect sufficient questionnaire data (all over 96% complete). No NH implemented intervention tools as planned. Only 16 S&W forms and 8 care pathways were completed. There was no evidence of harm. / Conclusions: Recruitment, retention and data collection processes were effective but the intervention not implemented. A full trial is not warranted. Trial registration number ISRCTN74109734 (https://doi.org/10.1186/ISRCTN74109734)

Effectiveness of primary care psychological therapy services for the treatment of depression and anxiety in people living with dementia: Evidence from national healthcare records in England

BACKGROUND: Depression and anxiety are common and deleterious in people living with dementia (PLWD). It is currently unknown whether routinely provided psychological therapy can help reduce these symptoms in PLWD. This study aimed to investigate improvements in depression and anxiety symptoms over the course of therapy offered in primary care psychological therapy services in PLWD and to compare outcomes to people without dementia. METHODS: National data from Improving Access to Psychological Therapies services (IAPT) across England linked with Hospital Episode Statistics data, the Mental Health Services Dataset, and HES-ONS mortality data were used to identify 1,549 PLWD who completed a course of psychological treatment in IAPT between 2012-2019 and a propensity score matched control group without identified dementia. Outcome measures included pre-post intervention changes in depression (PHQ-9) and anxiety (GAD-7) symptoms and therapy outcomes (reliable improvement, recovery, deterioration). FINDINGS: Symptoms of depression (t(1548)=31·05, p<·001) and anxiety (t(1548)=30·31, p<·001) improved in PLWD over the course of psychological therapy with large effect sizes (depression: d=-0·83; anxiety: d=-0·80). However, PLWD were less likely to reliably improve (OR=·75, 95%CI[·63,·88], p<·001) or recover (OR=·75, 95%CI[·64,·88], p=·001), and more likely to deteriorate (OR=1·35, 95%CI[1·03,1·78], p=·029) than a matched control sample without dementia. INTERPRETATION: Psychological therapy may be beneficial for PLWD with depression or anxiety, but it is currently not as effective as for people without dementia. More research is needed to improve access to psychological therapies and to understand this discrepancy and how therapies can be adapted to further improve outcomes. FUNDING: This work was supported by the Alzheimer's Society

Associations between psychological therapy outcomes for depression and incidence of dementia

BACKGROUND: Depression is an important, potentially modifiable dementia risk factor. However, it is not known whether effective treatment of depression through psychological therapies is associated with reduced dementia incidence. The aim of this study was to investigate associations between reduction in depressive symptoms following psychological therapy and the subsequent incidence of dementia. METHODS: National psychological therapy data were linked with hospital records of dementia diagnosis for 119808 people aged 65+. Participants received a course of psychological therapy treatment in Improving Access to Psychological Therapies (IAPT) services between 2012 and 2019. Cox proportional hazards models were run to test associations between improvement in depression following psychological therapy and incidence of dementia diagnosis up to eight years later. RESULTS: Improvements in depression following treatment were associated with reduced rates of dementia diagnosis up to 8 years later (HR = 0.88, 95% CI 0.83-0.94), after adjustment for key covariates. Strongest effects were observed for vascular dementia (HR = 0.86, 95% CI 0.77-0.97) compared with Alzheimer's disease (HR = 0.91, 95% CI 0.83-1.00). CONCLUSIONS: Reliable improvement in depression across psychological therapy was associated with reduced incidence of future dementia. Results are consistent with at least two possibilities. Firstly, psychological interventions to improve symptoms of depression may have the potential to contribute to dementia risk reduction efforts. Secondly, psychological therapies may be less effective in people with underlying dementia pathology or they may be more likely to drop out of therapy (reverse causality). Tackling the under-representation of older people in psychological therapies and optimizing therapy outcomes is an important goal for future research

Associations between psychological intervention for anxiety disorders and risk of dementia: a prospective cohort study using national health-care records data in England

BACKGROUND: Meta-analyses support an association between anxiety in older adulthood and dementia. The aim of this study was to use routinely collected health data to test whether treatment of anxiety disorders through psychological intervention is associated with a lower incidence of dementia. METHODS: In this prospective cohort study, data from nationally provided psychological therapy services in England termed Improving Access to Psychological Therapies from 2012 to 2019 were linked to medical records, including dementia diagnoses as defined by the tenth edition of the International Classification of Diseases, up to 8 follow-up years later. Inclusion criteria were as follows: (1) patients who were aged 65 years and older; (2) patients with a probable anxiety disorder; and (3) those with no previous or current diagnosis of dementia. Cox proportional hazards models were constructed to test whether reliable improvement in anxiety following psychological intervention was associated with future dementia incidence. The primary outcome was all-cause dementia and cases were identified using ICD-10 dementia codes from Hospital Episode Statistics, Mental Health Services Dataset, and mortality data. For main analyses, hazards ratios (HRs) are presented. FINDINGS: Data from 128 077 people aged 65 years and older attending a nationally provided psychological intervention service in England were linked to medical records. 88 019 (69·0%) of 127 064 participants with available gender data were women and 39 585 (31·0%) were men. 111 225 (95·9%) of 115 989 with available ethnicity data were of White ethnicity. The mean age of the sample was 71·55 years (SD 5·69). Fully adjusted models included data from 111 958 people after 16 119 were excluded due to missing data on key variables or covariates. 4510 (4·0%) of 111 958 participants had a dementia diagnosis. The remaining 107 448 (96·0%) were censored either at date of death or when the final follow-up period available for analyses was reached. People who showed reliable improvement in anxiety had lower rates of later dementia diagnosis (3·9%) than those who did not show reliable improvement (5·1%). Reliable improvement in anxiety following psychological intervention was associated with reduced incidence of all-cause dementia (HR 0·83 [95% CI 0·78-0·88]), Alzheimer's disease (HR 0·85 [0·77-0·94]), and vascular dementia (HR 0·80 [0·71-0·90]). Effects did not differ depending on anxiety disorder diagnosis. INTERPRETATION: Results showed that reliable improvement in anxiety from psychological therapy was associated with reduced incidence of future dementia. There are multiple plausible explanations for this finding and further research is needed to distinguish between these possibilities. Missing data in the sample limit reliability of findings. FUNDING: Alzheimer's Society, Medical Research Council, Wellcome Trust, and UCLH National Institute for Health and Care Research Biomedical Research Centre

Salivary cortisol in longitudinal associations between affective symptoms and midlife cognitive function: A British birth cohort study

Affective disorders are associated with accelerated cognitive ageing. However, current understanding of biological mechanisms which underlie these observed associations is limited. The aim of this study was to test: 1) Whether cortisol acts as a pathway in the association between depressive or anxiety symptoms across adulthood and midlife cognitive function; 2) Whether cortisol is associated with later depressive or anxiety symptoms, and cognitive function. Data were used from the National Child Development Study, a sample of infants born in mainland UK during one week of 1958. A measure of the accumulation of affective symptoms was derived from data collected from age 23 to 42 using the Malaise Inventory Scale. Salivary cortisol measures were available at age 44–45. Cognitive function (memory, fluency, information processing) and affective symptoms were assessed at the age of 50. Path models were run to test whether salivary cortisol explained the longitudinal association between depressive or anxiety disorder symptoms and cognitive function. Direct effects of affective symptoms are shown across early to middle adulthood on cognitive function in midlife (memory and information processing errors). However, there were no effects of affective symptoms on cognitive function through cortisol measures. Additionally, cortisol measures were not significantly associated with subsequent affective symptoms or cognitive function at the age of 50. These results do not provide clear evidence to suggest that cortisol plays a role in the association between affective symptoms and cognitive function over this period of time. These findings contribute to our understanding of how the association between affective symptoms and cognitive function operates over time