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Amyotrophic lateral sclerosis (ALS) is a multi‐system disorder that commonly affects cognition and behaviour. Verbal fluency impairments are consistently reported in ALS patients, and we aimed to investigate whether this deficit extends beyond the verbal domain. We further aimed to determine whether deficits are underpinned by a primary intrinsic response generation impairment (i.e., a global reduction across tasks), potentially related to apathy, or an inability to maintain responding over time (i.e., a 'drop off' pattern). Twenty‐two ALS patients and 21 demographically‐matched controls completed verbal and nonverbal fluency tasks (phonemic/semantic word fluency, design fluency, gesture fluency and ideational fluency), requiring the generation of responses over a specified time period. Fluency performance was analysed in terms of the overall number of novel items produced, as well as the number of items produced in the first 'initiation' and the remaining 'maintenance' time periods. ALS patients' overall performance was not globally reduced across tasks. Patients were impaired only on meaningful gesture fluency, which requires the generation of gestures that communicate meaning (e.g., waving). On phonemic fluency, ALS patients showed a 'drop off' pattern of performance, where they had difficulty maintaining responding over time, but this pattern was not evident on the other fluency tasks. Apathy did not appear to be related to fluency performance. The selective meaningful gesture fluency deficit, in the context of preserved meaningless gesture fluency, highlights that the retrieval of action knowledge may be weakened in early ALS. [ABSTRACT FROM AUTHOR]

Background: Although clozapine is the most effective antipsychotic for people with treatment-resistant schizophrenia (TRS), only 40% of people with TRS respond, and there is limited evidence for augmentation agents. Cannabidiol (CBD) reduces positive symptoms in individuals with schizophrenia, but no trials have specifically examined its efficacy in those with clozapine-resistant schizophrenia., Aims: To examine the clinical efficacy of CBD augmentation in people with clozapine-resistant schizophrenia., Method: This is a 12-week randomised, placebo-controlled, double-blind, parallel-group trial (registration number: ACTRN12622001112752). We will recruit 88 individuals with clozapine-resistant schizophrenia, randomised (1:1) to 1000 mg daily CBD versus placebo. Eligible individuals will be aged between 18 and 64 years, fulfil DSM-IV criteria for schizophrenia or schizoaffective disorder, have a total PANSS (Positive and Negative Syndrome Scale) score ≥60, have received oral clozapine for at least 18 weeks and have a clozapine level of >350 ng/mL. Interim analyses will be conducted at 25, 50 and 75% recruitment; these will also provide an opportunity to reallocate participants dependent on conditional power. The primary endpoint will be the difference in PANSS positive scores at the end of week 12. Secondary endpoints include depression, anxiety, sleep, quality of life, alcohol consumption, change in weight and metabolic syndrome components, and neurocognitive measures, as well as safety and tolerability., Discussion: Novel treatments for clozapine-resistant schizophrenia are urgently needed. If found to be effective, CBD may have a role as a novel and safe adjunct to clozapine.

Corpus callosum dysgenesis (CCD) is a congenital brain malformation that occurs when the development of the corpus callosum is disrupted, either partially or completely. The cognitive outcomes in individuals with CCD vary greatly, but generally the neuropsychological profile is characterised by slow processing speed, poor transfer of interhemispheric sensory-motor information, and impaired complex problem solving. Core language skills are often preserved in CCD, but there is some evidence that complex language may be impaired. Thus, the current study sought to examine whether spontaneous speech output was reduced in a cohort of individuals with CCD compared to age-matched controls. We further explored a series of factors that may be contributing to poor spontaneous speech in CCD, such as difficulties generating, selecting, and sequencing ideas for expression, as well as apathy and slowed processing speed. A cohort of 25 individuals with CCD and 39 neurotypical controls were enrolled in this study. Participants completed a picture description task to measure spontaneous speech output, alongside a series of cognitive and language baseline tests. Verbal and nonverbal fluency tasks gauged idea generation and sequencing, and sentence-level selection tasks measured idea selection. We found that, despite having largely intact core language skills, individuals with CCD produced significantly less spontaneous speech on the picture description task than controls. This language profile may be described as "adynamic". Further, we found that poor spontaneous speech output in CCD was related to problems generating ideas for expression, as individuals with CCD performed below controls on the verbal and nonverbal fluency tasks. Exploratory analyses revealed that apathy and slowed processing speed may be contributing factors. Adynamia in CCD is a novel finding that may be an intervention target for improving communication skills in this population., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: Propositional language and underlying executive functions can be impaired post-stroke and affect communication and quality of life. Current stroke screening tools are largely tailored to patients with aphasia, being either non-verbal or focussed on core language skills such as naming and repetition. The Brief Executive Language Screening Test (BELS) is a newly developed cognitive screening tool that assesses memory, oral apraxia, core language, as well as propositional language and associated executive functions that can be impacted and overlooked in stroke patients without aphasia. This study examines BELS sensitivity and specificity, and performance in acute to early sub-acute stroke relative to controls., Method: Cross-sectional BELS data from 88 acute left and right hemisphere stroke patients (within 7 weeks of stroke) and 116 age-matched healthy controls were compared using independent samples t-tests. ROC Curve Analysis was performed to determine a cutoff score for the BELS., Results: Left and right stroke patients were reduced on all propositional language subtests, and executive function subtests of inhibition, strategy, and selection. Differences were also observed for Oral Apraxia, Naming, and Memory. By contrast, Word Comprehension and Repetition, and Sentence Completion Initiation (after corrections applied) did not differ between groups. A total BELS score of 79.25/100 was highly sensitive (.89) and specific (.89) when classifying stroke patients and healthy controls., Conclusion: The BELS is brief, sensitive, suitable for bedside administration, and can aid in detection and rehabilitation of subtle executive language impairments. This in turn will help improve relationships and quality of life post-stroke.

Objective: Diffusion decision modeling (DDM) is a validated cognitive modeling method that has been used to provide insights into why older adults are slower than younger adults on a wide variety of cognitive tasks. DDM results have shown that increased processing time, caution, and sensorimotor factors have explained most of this slowing. Enhanced attentional processing of irrelevant information by older adults has also been reported in DDM studies but not explicitly studied. This enhanced processing of interference has been attributed to a motivational goal-directed decision to minimize errors by increasing accumulation of information (i.e., caution) rather than neurocognitive changes associated with aging. No DDM study has explicitly investigated interference and aging by comparing single task and dual performance within the framework of attentional control to explore more fully what and how attentional processes are involved. Our study attempts to fill these gaps., Method: We used a choice response time (RT) task of attentional switching with and without interference and applied the EZ-diffusion model on the data of 117 healthy younger and older adults aged 18-87., Results: Repeated mixed-measures analyses of variance of DDM parameters found that longer nondecision time was the main driver for longer RTs for older adults on both attentional switch tasks, but more prominently on the attentional switch trials of the dual task., Conclusions: Processing interference before the decision to switch attention was the main driver of increased RTs for older adults. Rather than motivational goal-directed factors for error minimization (i.e., caution), findings supported neurocognitive and inhibition deficit explanations. Future DDM studies into cognition and aging could consider how difficulties inhibiting interference impacts on the cognitive processes under investigation and whether the concept of caution is applicable. Findings raise functional considerations for older adults on visually oriented tasks that require attentional switching (e.g., work vs. driving). (PsycInfo Database Record (c) 2023 APA, all rights reserved).