Mood, Activity Participation, and Leisure Engagement Satisfaction (MAPLES): results from a randomised controlled pilot feasibility trial for low mood in acquired brain injury.

BACKGROUND: Acquired brain injury (ABI) is linked to increased depression risk. Existing therapies for depression in ABI (e.g., cognitive behavioural therapy) have mixed efficacy. Behavioural activation (BA), an intervention that encourages engaging in positively reinforcing activities, shows promise. The primary aims were to assess feasibility, acceptability, and potential efficacy of two 8-week BA groups. METHODS: Adults (≥ 18 years) recruited from local ABI services, charities, and self-referral via social media were randomised to condition. The Activity Planning group (AP; "traditional" BA) trained participants to plan reinforcing activities over 8 weeks. The Activity Engagement group (AE; "experiential" BA) encouraged engagement in positive activities within session only. Both BA groups were compared to an 8-week Waitlist group (WL). The primary outcomes, feasibility and acceptability, were assessed via recruitment, retention, attendance, and qualitative feedback on groups. The secondary outcome, potential efficacy, was assessed via blinded assessments of self-reported activity levels, depression, and anxiety (at pre- and post-intervention and 1 month follow-up) and were compared across trial arms. Data were collected in-person and remotely due to COVID-19. RESULTS: N = 60 participants were randomised to AP (randomised n = 22; total n = 29), AE (randomised n = 22; total n = 28), or re-randomised following WL (total n = 16). Whether in-person or remote, AP and AE were rated as similarly enjoyable and helpful. In exploring efficacy, 58.33% of AP members had clinically meaningful activity level improvements, relative to 50% AE and 38.5% WL. Both AP and AE groups had depression reductions relative to WL, but only AP participants demonstrated anxiety reductions relative to AE and WL. AP participants noted benefits of learning strategies to increase activities and learning from other group members. AE participants valued social discussion and choice in selecting in-session activities. CONCLUSIONS: Both in-person and remote group BA were feasible and acceptable in ABI. Though both traditional and experiential BA may be effective, these may have different mechanisms. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03874650. Protocol version 2.3, May 26 2020.

Emotional mental imagery generation during spontaneous future thinking: relationship with optimism and negative mood.

Optimism is known to buffer against negative mood. Thus, understanding the factors that contribute to individual variation in optimism may inform interventions for mood disorders. Preliminary evidence suggests that the generation of mental imagery-based representations of positive relative to negative future scenarios is related to optimism. This study investigated the hypothesis that an elevated tendency to generate positive relative to negative mental imagery during spontaneous future thinking would be associated with reduced negative mood via its relationship to higher optimism. Participants (N = 44) with varied levels of naturally occurring negative mood reported current levels of optimism and the real-time occurrence and characteristics of spontaneous thoughts during a sustained attention computer task. Consistent with hypotheses, higher optimism statistically mediated the relationship between a higher proportional frequency of positive relative to negative mental imagery during spontaneous future thinking and lower negative mood. Further, the relationship between emotional mental imagery and optimism was found for future, but not past, thinking, nor for verbal future or past thinking. Thus, a greater tendency to generate positive rather than negative imagery-based mental representations when spontaneously thinking about the future may influence how optimistic one feels, which in turn may influence one's experience of negative mood.

A randomized control trial of the effects of home-based online attention training and working memory training on cognition and everyday function in a community stroke sample.

Cognitive difficulties are common following stroke and can have widespread impacts on everyday functioning. Technological advances offer the possibility of individualized cognitive training for patients at home, potentially providing a low-cost, low-intensity adjunct to rehabilitation services. Using this approach, we have previously demonstrated post-training improvements in attention and everyday functioning in fronto-parietal stroke patients. Here we examine whether these benefits are observed more broadly in a community stroke sample. Eighty patients were randomized to either 4 weeks of online adaptive attention training (SAT), working memory training (WMT) or waitlist (WL). Cognitive and everyday function measures were collected before and after the intervention, and after 3 months. During training, weekly measures of patients' subjective functioning were collected. The training was well received and compliance good. No differences in our primary end-point, spatial bias, or other cognitive functions were observed. However, on patient-reported outcomes, SAT participants showed greater levels of improvement in everyday functioning than WMT or WL participants. In line with our previous work, everyday functioning improvements were greatest for patients with spatial impairments and those who received SAT training. Whether attention training can be recommended for stroke survivors depends on whether cognitive test performance or everyday functioning is considered more relevant.

Upscale fermenter design for lactic acid production from cheese whey permeate focusing on impeller selection and energy optimization.

This study focusses on the design and scale-up of industrial lactic acid production by fermentation of dairy cheese whey permeate based on standard methodological parameters. The aim was to address the shortcomings of standard scale-up methodologies and provide a framework for fermenter scale-up that enables the accurate estimation of energy consumption by suitable selection of turbine and speed for industrial deployment. Moreover, life cycle assessment (LCA) was carried out to identify the potential impacts and possibilities to reduce the operation associated emissions at an early stage. The findings showed that a 3000 times scale-up strategy assuming constant geometric dimensions and specific energy consumption (P/V w ) resulted in lower impeller speed and energy demand. The Rushton turbine blade (RTB) and LightninA315 four-blade hydrofoil (LA315) were found to have the highest and lowest torque output, respectively, at a similar P/V w of 2.8 kWm-3, with agitation speeds of 1.33 and 2.5 s-1, respectively. RTB demonstrating lower shear damage towards cells (up to 1.33 s-1) was selected because it permits high torque, low-power and acceptable turbulence. The LCA results showed a strong relation between the number of impellers installed and associated emissions suggesting a trade-off between mixing performance and environmental impacts. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05239-6.

Prevalence and predictive value of ICD-11 post-traumatic stress disorder and Complex PTSD diagnoses in children and adolescents exposed to a single-event trauma.

BACKGROUND: The 11th edition of the International Classification of Diseases (ICD-11) made a number of significant changes to the diagnostic criteria for post-traumatic stress disorder (PTSD). We sought to determine the prevalence and 3-month predictive values of the new ICD-11 PTSD criteria relative to ICD-10 PTSD, in children and adolescents following a single traumatic event. ICD-11 also introduced a diagnosis of Complex PTSD (CPTSD), proposed to typically result from prolonged, chronic exposure to traumatic experiences, although the CPTSD diagnostic criteria do not require a repeated experience of trauma. We therefore explored whether children and adolescents demonstrate ICD-11 CPTSD features following exposure to a single-incident trauma. METHOD: Data were analysed from a prospective cohort study of youth aged 8-17 years who had attended an emergency department following a single trauma. Assessments of PTSD, CPTSD, depressive and anxiety symptoms were performed at two to four weeks (n = 226) and nine weeks (n = 208) post-trauma, allowing us to calculate and compare the prevalence and predictive value of ICD-10 and ICD-11 PTSD criteria, along with CPTSD. Predictive abilities of different diagnostic thresholds were undertaken using positive/negative predictive values, sensitivity/specificity statistics and logistic regressions. RESULTS: At Week 9, 15 participants (7%) were identified as experiencing ICD-11 PTSD, compared to 23 (11%) experiencing ICD-10 PTSD. There was no significant difference in comorbidity rates between ICD-10 and ICD-11 PTSD diagnoses. Ninety per cent of participants with ICD-11 PTSD also met criteria for at least one CPTSD feature. Five participants met full CPTSD criteria. CONCLUSIONS: Reduced prevalence of PTSD associated with the use of ICD-11 criteria is likely to reduce identification of PTSD relative to using ICD-10 criteria but not relative to DSM-4 and DSM-5 criteria. Diagnosis of CPTSD is likely to be infrequent following single-incident trauma.

Dissociable effects of attention vs working memory training on cognitive performance and everyday functioning following fronto-parietal strokes.

Difficulties with attention are common following stroke, particularly in patients with frontal and parietal damage, and are associated with poor outcome. Home-based online cognitive training may have the potential to provide an efficient and effective way to improve attentional functions in such patients. Little work has been carried out to assess the efficacy of this approach in stroke patients, and the lack of studies with active control conditions and rigorous evaluations of cognitive functioning pre and post-training means understanding is limited as to whether and how such interventions may be effective. Here, in a feasibility pilot study, we compare the effects of 20 days of cognitive training using either novel Selective Attention Training (SAT) or commercial Working Memory Training (WMT) programme, versus a waitlist control on a range of attentional and working memory tasks. We demonstrate separable effects of each training condition, with SAT leading to improvements in spatial and non-spatial aspects of attention and WMT leading to improvements on closely related working memory tasks. In addition, both training groups reported improvements in everyday functioning, which were associated with improvements in attention, suggesting that improving attention may be of particular importance in maximising functional improvements in this patient group.

Spontaneous cognition in dysphoria: reduced positive bias in imagining the future.

Anomalies in future-oriented cognition are implicated in the maintenance of emotional disturbance within cognitive models of depression. Thinking about the future can involve mental imagery or verbal-linguistic mental representations. Research suggests that future thinking involving imagery representations may disproportionately impact on-going emotional experience in daily life relative to future thinking not involving imagery (verbal-linguistic representation only). However, while higher depression symptoms (dysphoria) are associated with impaired ability to deliberately generate positive relatively to negative imagery representations of the future (when instructed to do so), it is unclear whether dysphoria is associated with impairments in the tendency to do so spontaneously (when not instructed to deliberately generate task unrelated cognition of any kind). The present study investigated dysphoria-linked individual differences in the tendency to experience spontaneous future-oriented cognition as a function of emotional valence and representational format. Individuals varying in dysphoria level reported the occurrence of task unrelated thoughts (TUTs) in real time while completing a sustained attention go/no-go task, during exposure to auditory cues. Results indicate higher levels of dysphoria were associated with lower levels of positive bias in the number of imagery-based future TUTs reported, reflecting higher negative imagery-based future TUT generation (medium to large effect size), and lower positive imagery-based TUT generation (small to medium effect size). Further, this dysphoria-linked bias appeared to be specific in temporal orientation (future, not past) and representational format (imagery, not non-imagery). Reduced tendency to engage in positive relative to negative imagery-based future thinking appears to be implicated in dysphoria.

Anticipated and imagined futures: prospective cognition and depressed mood following brain injury.

OBJECTIVES: Depression, which is common following acquired brain injury (ABI), has been shown to predict cognitive impairment, rehabilitation outcome, and quality of life. Whilst many studies have examined links between depression and cognitive-affective processing in the non-ABI population, their applicability to this important clinical group, where cognitive difficulties can be marked, remains unknown. Here, we investigated biases in prospective cognition, which is known to be disrupted in (non-ABI) depression yet important for well-being. DESIGN: Cross-sectional design with three groups (depressed ABI, non-depressed ABI, and non-ABI control participants). Continuous data were additionally analysed in correlation analyses. METHODS: Individuals with ABI varying in extent of self-reported depression and matched non-ABI control participants completed assessments of mood and prospective cognition (anticipating and imagining future events), alongside background tests of executive function and fluid intelligence. RESULTS: Relative to non-depressed ABI and control participants, depressed ABI individuals demonstrated a reduced positive bias in prospective cognition: whereas non-depressed ABI and control participants generated more examples of likely or possible positive versus negative future events, there was no evidence for such a positive bias in depressed ABI participants. Non-depressed ABI and control participants also reported more vivid mental imagery for positive versus negative future scenarios, whereas such a pattern was not evident in depressed ABI participants. This pattern emerged despite background impairments in fluid intelligence and executive function associated with ABI. CONCLUSIONS: These findings (1) elucidate depression-linked cognitive-affective processes following ABI, where cognitive difficulties are common, and (2) highlight psychological processes associated with depression that are common to ABI and non-ABI populations. PRACTITIONER POINTS: Clinical implications A relative negative bias in future-directed cognition is associated with depressed mood in individuals with chronic ABI. Such processes may contribute to the onset and maintenance of depression following ABI. These findings suggest it may be important to consider a role for prospective cognition in psychological interventions for depression following ABI. Limitations of the study The extent to which depressed mood following ABI is associated with biases in other cognitive domains remains unclear. Whether similar patterns would be observed in acute patients with more profound cognitive difficulties requires further investigation. Despite large effect sizes, our sample size is modest; these effects thus require replication in larger groups.

Modelling solar photovoltaic systems on dairy farms for cost savings and GHG emission reduction.

Rising on-farm electricity demand, coupled with surges in electricity prices, has increased costs associated with milk production. Additionally, the use of grid electricity with a high carbon footprint depreciates the environmental performance of dairy farming. We assessed the potential of photovoltaic (PV) systems installed on dairy parlours under different policy incentives to reduce electricity costs and the carbon footprint of dairy farms in Ireland. The HOMER Pro software was employed to model electricity consumption, generation and economic performance of four 15-year PV project scenarios for 11 Irish farms. Scenarios considering the targeted agricultural modernisation scheme II (TAMS) and the microgeneration support scheme are assessed. The results show that PV systems are a feasible option to power dairy farms when current energy prices and inflation rates are applied. Small systems eligible for TAMS grants presented an average discounted payback period of 5 years, making them a better option for farmers than larger projects, which had an average payback period of 8.5 years. The deployment of PV systems reduced the GHG intensity of electricity consumed at the farms by up to 29 %.

Trauma Memory Characteristics and Neurocognitive Performance in Youth Exposed to Single-Event Trauma.

Cognitive models of posttraumatic stress disorder (PTSD) highlight characteristics of trauma memories, such as disorganisation, as key mechanisms in the aetiology of the disorder. However, studies investigating trauma memory in youth have provided inconsistent findings. Research has highlighted that PTSD in youth may be accompanied by difficulties in neurocognitive functioning, potentially impacting ability to recall the trauma memory. The present study sought to investigate both trauma memory characteristics and neurocognitive functioning in youth aged 8-17 years. Youths exposed to single-event trauma, with (N = 29, Mage = 13.6, 21 female) and without (N = 40, Mage = 13.3, 21 female) a diagnosis of PTSD, completed self-report measures of trauma memory, a narrative memory task and a set of neurocognitive tests two to six months post-trauma. A group of non trauma-exposed youths (N = 36, Mage = 13.9, 27 female) were compared on narrative and neurocognitive tasks. Results indicated that trauma memories in youth with, versus without, PTSD were more sensory-laden, temporally disrupted, difficult to verbally access, and formed a more 'central' part of their identity. Greater differences were observed for self-reported memory characteristics compared to narrative characteristics. No between group differences in neurocognitive function were observed. Self-reported trauma memory characteristics highlight an important factor in the aetiology of PTSD. The observed lack of significant differences in neurocognitive ability potentially suggests that cognitive factors represent a more relevant treatment target than neurocognitive factors in single-event PTSD. Further research to understand the cognitive factors represented by self-reported trauma memory characteristics is recommended.

Measuring Intolerance of Uncertainty After Acquired Brain Injury: Factor Structure, Reliability, and Validity of the Intolerance of Uncertainty Scale-12.

Intolerance of uncertainty (IU) is a risk factor for poor mental health. Acquired brain injury (ABI; for example, stroke, traumatic brain injury) often brings considerable uncertainty and increased mood disorder vulnerability. The Intolerance of Uncertainty Scale-Short Form (IUS-12) is a brief, well-validated IU measure in non-ABI samples, comprising two subscales, namely, Prospective Anxiety and Inhibitory Anxiety. Here, for the first time, we investigated its reliability and validity (N = 118), and factor structure (N = 176), in ABI. Both subscales had high test-retest reliability (intraclass correlation coefficients [ICCs] of .75 and .86) and were significantly associated with mood disorder symptoms. The two-factor model was superior to a one-factor IU model fit. Some fit statistics were less than optimal (standardized root mean square residual [SRMR] = 0.06, root mean square error of approximation [RMSEA] = 0.09); hence, exploration of other factor structures in other ABI samples may be warranted. Nonetheless, the IUS-12 appears suitable in ABI.

Developing behavioural activation for people with acquired brain injury: a qualitative interpretive description study of barriers and facilitators to activity engagement.

BACKGROUND: Acquired brain injuries (ABI) from stroke, head injury, or resected brain tumours are associated with poor emotional wellbeing and heightened risk of mood disorder. Common sequalae of ABI, such as poor attention and memory, can create barriers to the efficacy of cognitively demanding mood interventions, such as Cognitive Behavioural Therapy (CBT). Behavioural Activation (BA), where individuals plan and engage in reinforcing activities, is a promising alternative due to lower cognitive demands. However, BA was initially developed in clinical populations without ABI where the primary barriers to activity engagement were low mood and anxious avoidance. Additionally, BA can incorporate a range of techniques (e.g., mood monitoring, activity scheduling, targeting avoidance, contingency management) and psychoeducational topics (e.g., mindfulness, managing uncertainty; social/communication skills). Exploring barriers and facilitators to adopting specific BA components in ABI is an important aim. METHODS: Semi-structured interviews were conducted with purposively selected ABI survivors (N = 16) with both low and high depressive symptoms, and family members (N = 7). Questions focused on routine and enjoyable activities, and feedback on 10 different BA techniques and associated psychoeducational topics. Transcripts were analysed using an interpretive description framework. Analysis was informed by field notes, reflexivity diaries, and peer debriefing. RESULTS: The final constructed framework, Creating Sustainable Engagement, comprises a two-tier hierarchy. Higher-level themes concerned core perspectives of BA, regardless of BA component discussed. This included identifying optimal time windows for different BA components (Right Tool at the Right Time), that BA components should, at least initially, not be burdensome or fatiguing (Perceived Effort), that emotional readiness to confront activity-mood relationships should be addressed (Emotional Impact), and that planned BA activities be consistent with individual values (Relation to Values). Lower-level themes concerned specific BA components: Of these, activity scheduling, procedures targeting avoidance, managing uncertainty and social/communication skills were generally well-received, while mood monitoring, contingency management, and mindfulness had mixed feedback. CONCLUSIONS: BA is a widely scalable intervention that can be adapted for ABI. This study provides a novel framework on implementing a range of BA components in ABI and adds to the limited evidence on which components may be particularly suitable.

Rehabilitation of executive function and social cognition impairments after brain injury.

PURPOSE OF REVIEW: Brain injury is a major cause of long-term disability. Executive and social cognition sequelae are associated with poor outcome. This review examines recent evidence on the efficacy of rehabilitation in these areas. RECENT FINDINGS: Accumulating evidence shows that interventions that work with patients on developing insight and strategies to offset executive impairments can produce significant benefits. Training of specific capacities, such as working memory, holds some promise, but more needs to be known about effect generalization. Evidence on social cognition rehabilitation following brain injury is sparse. Although there are some encouraging early results, more information on the clinical significance of change for everyday function is required. SUMMARY: Rehabilitation in these areas is inherently difficult but vital if outcomes are to improve. Significant gains have been reported, and further work applying appropriate methods is urgently required.

Emotion and personality factors influence the neural response to emotional stimuli.

Lindquist et al. assess the neural evidence for locationist versus psychological construction accounts of human emotion. A wealth of experimental and clinical investigations show that individual differences in emotion and personality influence emotion processing. These factors may also influence the brain's response to emotional stimuli. A synthesis of the relevant neuroimaging data must therefore take these factors into consideration.

Economic and environmental sustainability analysis of seaweed farming: Monetizing carbon offsets of a brown algae cultivation system in Ireland.

This paper examines the economic and environmental costs of seaweed cultivation (Alaria esculenta) in Ireland and evaluates the potential revenue made on the voluntary carbon offset market (VCOM). The life cycle assessment (LCA) results revealed the cultivation equipment with the polypropylene used for the cultivation lines contributes the highest share of impacts due to their replacement rate. This study suggests long-term employment of farm infrastructure and increased seaweed yield could enhance the environmental sustainability of the system. Moreover, life cycle costing (LCC) indicates the seaweed farm in Ireland is economically feasible over a 20-year lifespan. However, the revenue generated on the VCOM from the seaweed carbon assimilation was minimal, contributing to only 5% of the revenue. This study concludes that further development of the seaweed market with stabilized biomass prices and producing a range of viable products from seaweed biomass will be a major factor in the economic sustainability.

Exploring the basis and boundary conditions of SenseCam-facilitated recollection.

SenseCam review has been shown to promote and sustain subsequent access to memories that might otherwise remain inaccessible. While SenseCam review facilitates recollection for personally experienced events, we know little about the boundary conditions under which this operates and about how underlying processing mechanisms can be optimally recruited to offset memory impairments of the sort that occur in dementia. This paper considers some of these issues with a view to targeting future research that not only clarifies our evolving body of theory about how memory works, but also informs about how memory-assistive technologies for patients might be employed to maximal effect. We begin by outlining key factors that are known to influence recollection. We then examine variability in the decline of memory function both in normal ageing and in dementia. Attention is drawn to similarities in the recollection deficits associated with depression and dementia, and we suggest that this may reflect shared underlying mechanisms. We conclude by discussing how one particular theoretical rationale can be intersected with key SenseCam capabilities to define priorities for ongoing and future SenseCam research.

SenseCam, imagery and bias in memory for wellbeing.

Identifying and modifying the negative interpretation bias that characterises depression is central to successful treatment. While accumulating evidence indicates that mental imagery is particularly effective in the modification of emotional bias, this research typically incorporates static and unrelated ambiguous stimuli. SenseCam technology, and the resulting video-like footage, offers an opportunity to produce training stimuli that are dynamic and self-relevant. Here participants experienced several ambiguous tasks and subsequently viewed SenseCam footage of the same tasks, paired with negative or positive captions. Participants were trained to use mental imagery to inter-relate SenseCam footage and captions. Participants reported increased levels of happy mood, reduced levels of sad mood, and increased task enjoyment following SenseCam review with positive versus negative captions. This shift in emotional bias was also evident at 24-hour follow-up, as participants recollected greater task enjoyment for those tasks previously paired with positive captions. Mental imagery appears to play an important role in this process. These preliminary results indicate that in healthy volunteers, SenseCam can be used within a bias modification paradigm to shift mood and memory for wellbeing associated with performing everyday activities. Further refinements are necessary before similar methods can be applied to individuals suffering from subclinical and clinical depression.

Alternative seagrass wrack management practices in the circular bioeconomy framework: A life cycle assessment approach.

Despite providing important ecological functions, seagrass accumulation causes environmental and economic issues, including eutrophication and tourism reduction. Nowadays, seagrass wrack is commonly removed from the beaches and landfilled, which is considered the least desirable practice according to the European Union (EU) Waste Framework Directive. In this study, different management strategies for seagrass valorisation, including anaerobic digestion (AD), composting and ecological restoration, were considered using a life cycle assessment (LCA) perspective. The aim of the work was to evaluate more ecological and economic alternatives to landfill and to provide a robust evaluation method for public and private companies. An economic assessment was subsequently conducted, considering both direct and indirect impacts with a life cycle costing (LCC) approach. A selected beach located in the Northeast Mediterranean Sea was considered as a relevant case-study. The environmental impacts of the seagrass management scenarios were evaluated with the method ReCiPe 2016H, using both midpoint and endpoint levels. LCA results showed that ecological restoration and AD were the best alternatives in terms of environmental performances because of biogas production used as a renewable energy source. The impacts of the alternative management strategies were significantly lower than the current landfill strategy, -70% considering the categories of human health, ecosystems and resources, and -95% considering global warming potential category. The LCC analysis proved that composting was the best alternative (NPV > 1.27 M€), due to lower operating costs and higher fertilizer value. The obtained results can help beach management companies and public administrations to select the best operational strategies to reduce the environmental and economic impact of seagrass collection and treatment.

Anaerobic digestion of poultry litter - A consequential life cycle assessment.

Concentrated land spreading of poultry litter has the potential to cause nutrient build-up in soils, eutrophication of water bodies, air pollution and the spread of pathogens. As a result, alternative routes for the disposal of poultry litter are being sought. A consequential life cycle assessment was conducted to examine several scenarios where biogas produced from poultry litter is used to generate heat and electricity or is upgraded to biomethane which can substitute natural gas. For all of the scenarios considered in this study, diverting poultry litter to anaerobic digestion leads to reduced environmental impacts for global warming, fine particulate matter formation and terrestrial acidification. However, the extent to which environmental impacts are reduced varies significantly across the scenarios. Displaced processes including electricity or natural gas, peat moss production and avoided land spreading of litter contribute the most to reducing environmental impacts. Consequential life cycle assessment is a suitable tool to inform decision-makers about the impact of introducing a new multifunctional technology like anaerobic digestion when considering the systems which are displaced. The results show the range of potential environmental outcomes, rather than predicting a single most-likely outcome. The results of this study indicate that anaerobic digestion is a suitable disposal route for poultry litter which may lead to reduced environmental impacts. This type of analysis is recommended when considering alternative feedstocks and valorisation pathways in the circular economy.

Mood, Activity Participation, and Leisure Engagement Satisfaction (MAPLES): a randomised controlled pilot feasibility trial for low mood in acquired brain injury.

BACKGROUND: Acquired brain injury (ABI) affects approximately 79.3 million individuals annually and is linked with elevated rates of depression and low mood. Existing methods for treating depression in ABI have shown mixed efficacy. Behavioural activation (BA) is a potentially promising intervention. Its premise is that individuals with low mood avoid planning and engaging in activities due to low expectations of a positive outcome. Consequently, their exposure to positive reinforcement is reduced, exacerbating low mood. BA aims to break this cycle by encouraging activity planning and engagement. It is unknown whether cognitive demands of traditional BA may undermine efficacy in ABI. Here, we assess the feasibility and acceptability of two groups designed to increase activity engagement. In the activity planning group (traditional BA), the importance of meaningful and positive activity will be discussed and participants encouraged to plan/engage in activities in everyday life. The activity engagement group (experiential BA) instead focuses on engagement in positive experiences (crafts, games, discussion) within the group. The primary aims are to evaluate the feasibility and acceptability of the two groups in ABI. A secondary aim is to explore relative efficacy of the groups compared to an equivalent period of waitlist controls. METHOD: This study outlines a parallel-arm pilot feasibility trial for individuals with low mood and ABI that compares a traditional vs experiential BA group vs waitlist controls. Adults (≥ 18 years) will be recruited from local ABI services and randomised to condition. Feasibility and acceptability will be assessed via recruitment, retention, attendance and participant feedback. Groups will be compared (pre- and post-intervention and 1 month follow-up) by assessing self-reported activity engagement. Secondary outcomes include self-report measures of depression, anxiety, post-traumatic distress related to the ABI, motivation, participation and sense of control over one's life. ETHICS AND DISSEMINATION: The trial has been approved by the Health Research Authority of the NHS in the UK (East of England-Cambridge Central, REF 18/EE/0305). Results will inform future research on interventions for mood in ABI and be disseminated broadly via peer-reviewed journals, conference presentations and social media. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03874650 pre-results. Protocol version 2.1, March 5, 2019.