596 research outputs found

    The effect of sertraline on emotional processing: secondary analyses of the PANDA randomised controlled trial

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    Background. According to the cognitive neuropsychological model, antidepressants reduce symptoms of depression and anxiety by increasing positive relative to negative information processing. Most studies of whether antidepressants alter emotional processing use small samples of healthy individuals, which lead to low statistical power and selection bias and are difficult to generalise to clinical practice. We tested whether the selective serotonin reuptake inhibitor (SSRI) sertraline altered recall of positive and negative information in a large randomised controlled trial (RCT) of patients with depressive symptoms recruited from primary care. Methods. The PANDA trial was a pragmatic multicentre double-blind RCT comparing sertraline with placebo. Memory for personality descriptors was tested at baseline and 2 and 6 weeks after randomisation using a computerised emotional categorisation task followed by a free recall. We measured the number of positive and negative words correctly recalled (hits). Poisson mixed models were used to analyse longitudinal associations between treatment allocation and hits. Results. A total of 576 participants (88% of those randomised) completed the recall task at 2 and 6 weeks. We found no evidence that positive or negative hits differed according to treatment allocation at 2 or 6 weeks (adjusted positive hits ratio = 0.97, 95% CI 0.90–1.05, p = 0.52; adjusted negative hits ratio = 0.99, 95% CI 0.90–1.08, p = 0.76). Conclusions. In the largest individual placebo-controlled trial of an antidepressant not funded by the pharmaceutical industry, we found no evidence that sertraline altered positive or negative recall early in treatment. These findings challenge some assumptions of the cognitive neuropsychological model of antidepressant action

    Human perceptual learning is delayed by the N-methyl-D-aspartate receptor partial agonist D-cycloserine

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    Background: The optimisation of learning has long been a focus of scientific research, particularly in relation to improving psychological treatment and recovery of brain function. Previously, partial N-methyl-D-aspartate agonists have been shown to augment reward learning, procedural learning and psychological therapy, but many studies also report no impact of these compounds on the same processes. Aims: Here we investigate whether administration of an N-methyl-D-aspartate partial agonist (D-cycloserine) modulates a previously unexplored process – tactile perceptual learning. Further, we use a longitudinal design to investigate whether N-methyl-D-aspartate-related learning effects vary with time, thereby providing a potentially simple explanation for apparent mixed effects in previous research. Methods: Thirty-four volunteers were randomised to receive one dose of 250 mg D-cycloserine or placebo 2 h before tactile sensitivity training. Tactile perception was measured using psychophysical methods before and after training, and 24/48 h later. Results: The placebo group showed immediate within-day tactile perception gains, but no further improvements between-days. In contrast, tactile perception remained at baseline on day one in the D-cycloserine group (no within-day learning), but showed significant overnight gains on day two. Both groups were equivalent in tactile perception by the final testing – indicating N-methyl-D-aspartate effects changed the timing, but not the overall amount of tactile learning. Conclusions: In sum, we provide first evidence for modulation of perceptual learning by administration of a partial N-methyl-D-aspartate agonist. Resolving how the effects of such compounds become apparent over time will assist the optimisation of testing schedules, and may help resolve discrepancies across the learning and cognition domains

    Dynamic modulation of inequality aversion in human interpersonal negotiations.

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    Negotiating with others about how finite resources should be distributed is an important aspect of human social life. However, little is known about mechanisms underlying human social-interactive decision-making in gradually evolving environments. Here, we report results from an iterative Ultimatum Game (UG), in which the proposer's facial emotions and offer amounts were sampled probabilistically based on the participant's decisions. Our model-free results confirm the prediction that both the proposer's facial emotions and the offer amount should influence acceptance rates. Model-based analyses extend these findings, indicating that participants' decisions in the UG are guided by aversion to inequality. We highlight that the proposer's facial affective reactions to participant decisions dynamically modulate how human decision-makers perceive self-other inequality, relaxing its otherwise negative influence on decision values. This cognitive model underlies how offers initially rejected can gradually become more acceptable under increasing affective load (predictive accuracy ~86%). Furthermore, modelling human choice behaviour isolated the role of the central arousal systems, assessed by measuring pupil size. We demonstrate that pupil-linked central arousal systems selectively encode a key component of subjective decision values: the magnitude of self-other inequality. Taken together, our results demonstrate that, under affective influence, aversion to inequality is a malleable cognitive process

    Variants of Tn 6924 , a Novel Tn 7 Family Transposon Carrying the bla NDM Metallo-β-Lactamase and 14 Copies of the aphA6 Amikacin Resistance Genes Found in Acinetobacter baumannii

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    To date, efforts to study the resistance mechanisms of carbapenem-resistant Acinetobacter baumannii have been largely focused on the two major globally distributed clones (GC1 and GC2). ST85 is an emerging sequence type, and unlike other clones, it is associated with the carriage of the bla NDM gene. </jats:p

    Effects of the 5-HT2C receptor agonist meta-chlorophenylpiperazine on appetite, food intake and emotional processing in healthy volunteers

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    RATIONALE: The treatment of obesity is an increasing global health priority, yet few effective drug treatments are currently available. The discovery of novel anti-obesity therapies could be assisted by the validation of experimental (translational) medicine models in healthy volunteers that assess efficacy and safety at an early stage of drug development. OBJECTIVES: The aim of this study was to examine the effects of the 5-HT2C receptor agonist meta-chlorophenylpiperazine (mCPP) in an experimental medicine model assessing both appetite and mood. METHODS: Using a between-subjects, double-blind, placebo-controlled design, 24 male and 24 female participants were randomly assigned to either placebo, 15- or 30-mg mCPP treatment groups. Lunch was eaten from a Universal Eating Monitor (UEM) that measured eating rate, and the participants completed the P1vital® Oxford Emotional Test Battery (ETB) and a series of appetite and mood ratings. RESULTS: mCPP reduced appetite and, in women, enhanced measures of satiation. The drug also enhanced memory for emotional material in the word recall and recognition memory tasks of the ETB. CONCLUSIONS: The results provide new insight into the effects of mCPP on appetite, satiety and memory in humans. In addition, our data provide an illustration of the value of measuring changes in appetite and mood in healthy volunteers to determine the potential efficacy and safety of novel anti-obesity drugs

    EQUILÍBRIO ASSOCIADO AO RISCO DE QUEDAS EM IDOSOS NÃO INSTITUCIONALIZADOS

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    Realizar uma revisão integrativa da literatura sobre a relação existente entre o equilíbrio e o risco de queda da população idosa. Métodos: trata-se de uma revisão integrativa da literatura entre os anos de 2007 a 2016, que ocorreu por meio de consulta à Biblioteca Virtual em Saúde (BVS) utilizando os descritores "acidentes por quedas", "idoso" e "equilíbrio postural”, separados pelo operador boleano “AND”, sendo selecionados 7 estudos. Resultados: em relação ao equilíbrio em idosos associado ao risco de quedas e ao aumento dessa ocorrência, os 7 artigos mantiveram uma relação na abordagem quando evidenciaram que as alterações no equilíbrio geram a predisposição e aumenta o risco de quedas na população idosa. Conclusões: percebe-se que é necessária a identificação precoce dos riscos para a prevenção de quedas, e desta forma, atentar-se para a realização de ações preventivas que estimulem a responsabilidade do autocuidado, melhor qualidade de vida e o exercício da autonomia entre esses indivíduos

    Role of the mesoamygdaloid dopamine projection in emotional learning

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    Amygdala dopamine is crucially involved in the acquisition of Pavlovian associations, as measured via conditioned approach to the location of the unconditioned stimulus (US). However, learning begins before skeletomotor output, so this study assessed whether amygdala dopamine is also involved in earlier 'emotional' learning. A variant of the conditioned reinforcement (CR) procedure was validated where training was restricted to curtail the development of selective conditioned approach to the US location, and effects of amygdala dopamine manipulations before training or later CR testing assessed. Experiment 1a presented a light paired (CS+ group) or unpaired (CS- group) with a US. There were 1, 2 or 10 sessions, 4 trials per session. Then, the US was removed, and two novel levers presented. One lever (CR+) presented the light, and lever pressing was recorded. Experiment 1b also included a tone stimulus. Experiment 2 applied intra-amygdala R(+) 7-OH-DPAT (10 nmol/1.0 A mu l/side) before two training sessions (Experiment 2a) or a CR session (Experiment 2b). For Experiments 1a and 1b, the CS+ group preferred the CR+ lever across all sessions. Conditioned alcove approach during 1 or 2 training sessions or associated CR tests was low and nonspecific. In Experiment 2a, R(+) 7-OH-DPAT before training greatly diminished lever pressing during a subsequent CR test, preferentially on the CR+ lever. For Experiment 2b, R(+) 7-OH-DPAT infusions before the CR test also reduced lever pressing. Manipulations of amygdala dopamine impact the earliest stage of learning in which emotional reactions may be most prevalent

    Variation in recognition of happy and sad facial expressions and self-reported depressive symptom severity: A prospective cohort study

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    Objective: Cognitive theories suggest people with depression interpret self-referential social information negatively. However, it is unclear whether these biases precede or follow depression. We investigated whether facial expression recognition was associated with depressive symptoms cross-sectionally and longitudinally. Methods: Prospective cohort study of people who had visited UK primary care in the past year reporting depressive symptoms (n = 509). Depressive symptoms were measured using the Patient Health Questionnaire (PHQ-9) at four time-points, 2 weeks apart. A computerised task assessed happy and sad facial expression recognition at three time-points (n = 505 at time 1). The unbiased hit rate measured ability to recognise emotions accounting for any general tendency to identify the emotion when it was not present. Results: The sample included the full range of depressive symptom severity, with 45% meeting diagnostic criteria for depression. There was no evidence that happy or sad unbiased hit rates were associated with concurrent or subsequent depressive symptoms. There was weak evidence that, for every additional face incorrectly classified as happy, concurrent PHQ-9 scores reduced by 0.05 of a point (95% CI = -0.10 to 0.002, p = 0.06 after adjustment for confounders). This association was strongest for more ambiguous facial expressions (interaction term p<0.001). Limitations: This was an observational study with relatively short follow-up (6 weeks) and small changes in depressive symptoms and emotion recognition. Only 7% of invited patients consented to participate. Conclusions: Reduced misclassifications of ambiguous faces as happy could be a state marker of depression, but was not associated with subsequent depressive symptoms. Future research should focus on the interpretation of ambiguous social informatio

    The effects of using the PReDicT Test to guide the antidepressant treatment of depressed patients: study protocol for a randomised controlled trial

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    Background Antidepressant medication is commonly used to treat depression. However, many patients do not respond to the first medication prescribed and improvements in symptoms are generally only detectable by clinicians 4–6 weeks after the medication has been initiated. As a result, there is often a long delay between the decision to initiate an antidepressant medication and the identification of an effective treatment regimen. Previous work has demonstrated that antidepressant medications alter subtle measures of affective cognition in depressed patients, such as the appraisal of facial expression. Furthermore, these cognitive effects of antidepressants are apparent early in the course of treatment and can also predict later clinical response. This trial will assess whether an electronic test of affective cognition and symptoms (the Predicting Response to Depression Treatment Test; PReDicT Test) can be used to guide antidepressant treatment in depressed patients and, therefore, hasten treatment response compared to a control group of patients treated as usual. Methods/design The study is a randomised, two-arm, multi-centre, open-label, clinical investigation of a medical device, the PReDicT Test. It will be conducted in five European countries (UK, France, Spain, Germany and the Netherlands) in depressed patients who are commencing antidepressant medication. Patients will be randomised to treatment guided by the PReDicT Test (PReDicT arm) or to Treatment as Usual (TaU arm). Patients in the TaU arm will be treated as per current standard guidelines in their particular country. Patients in the PReDicT arm will complete the PReDicT Test after 1 (and if necessary, 2) weeks of treatment. If the test indicates non-response to the treatment, physicians will be advised to immediately alter the patient’s antidepressant therapy by dose escalation or switching to another compound. The primary outcome of the study is the proportion of patients showing a clinical response (defined as 50% or greater decrease in baseline scores of depression measured using the Quick Inventory of Depressive Symptoms – Self-Rated questionnaire) at week 8. Health economic and acceptability data will also be collected and analysed. Discussion This trial will test the clinical efficacy, cost-effectiveness and acceptability of using the novel PReDicT Test to guide antidepressant treatment selection in depressed patients
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