66 research outputs found

    The effect of cannabis use and cognitive reserve on age at onset and psychosis outcomes in first-episode schizophrenia

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    Cannabis use is associated with a younger age at onset of psychosis, an indicator of poor prognosis, but better cognitive function, a positive prognostic indicator. We aimed to clarify the role of age at onset and cognition on outcomes in cannabis users with first-episode schizophrenia as well as the effect of cannabis dose and cessation of use

    Dissociable effects of 5-HT2C receptor antagonism and genetic inactivation on perseverance and learned non-reward in an egocentric spatial reversal task

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    Cognitive flexibility can be assessed in reversal learning tests, which are sensitive to modulation of 5-HT2C receptor (5-HT2CR) function. Successful performance in these tests depends on at least two dissociable cognitive mechanisms which may separately dissipate associations of previous positive and negative valence. The first is opposed by perseverance and the second by learned non-reward. The current experiments explored the effect of reducing function of the 5-HT2CR on the cognitive mechanisms underlying egocentric reversal learning in the mouse. Experiment 1 used the 5-HT2CR antagonist SB242084 (0.5 mg/kg) in a between-groups serial design and Experiment 2 used 5-HT2CR KO mice in a repeated measures design. Animals initially learned to discriminate between two egocentric turning directions, only one of which was food rewarded (denoted CS+, CS−), in a T- or Y-maze configuration. This was followed by three conditions; (1) Full reversal, where contingencies reversed; (2) Perseverance, where the previous CS+ became CS− and the previous CS− was replaced by a novel CS+; (3) Learned non-reward, where the previous CS− became CS+ and the previous CS+ was replaced by a novel CS-. SB242084 reduced perseverance, observed as a decrease in trials and incorrect responses to criterion, but increased learned non-reward, observed as an increase in trials to criterion. In contrast, 5-HT2CR KO mice showed increased perseverance. 5-HT2CR KO mice also showed retarded egocentric discrimination learning. Neither manipulation of 5-HT2CR function affected performance in the full reversal test. These results are unlikely to be accounted for by increased novelty attraction, as SB242084 failed to affect performance in an unrewarded novelty task. In conclusion, acute 5-HT2CR antagonism and constitutive loss of the 5-HT2CR have opposing effects on perseverance in egocentric reversal learning in mice. It is likely that this difference reflects the broader impact of 5HT2CR loss on the development and maintenance of cognitive function

    Severe COVID-19 anxiety among adults in the UK: protocol for a cohort study and nested feasibility trial of modified cognitive-behavioural therapy for health anxiety

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    Introduction: Some people are so anxious about COVID-19 that it impairs their functioning. However, little is known about the course of severe COVID-19 anxiety or what can be done to help people who experience it. / Methods and analysis: Cohort study with a nested feasibility trial with follow-up at 3 and 6 months. We recruited 306 people who were aged 18 and over, lived in the UK and had severe COVID-19 anxiety (indicated by a score of 9 or more on the Coronavirus Anxiety Scale (CAS)). To take part in the nested feasibility trial, participants also had to have a score of 20 or more on the Short Health Anxiety Inventory. We excluded people from the trial if they had had COVID-19 within the previous 4 weeks, if they were currently self-isolating or if they were already receiving psychological treatment. We publicised the study nationally through adverts, social media and posts on message boards. We also recruited participants via clinicians working in primary and secondary care NHS services in London. All those in the active arm will be offered 5–10 sessions of remotely delivered modified cognitive–behavioural therapy for health anxiety (CBT-HA). We will examine the proportion of participants who remain above threshold on the CAS at 3 and 6 months and factors that influence levels of COVID-19 anxiety over 6 months using mixed effects logistic regression. The key feasibility metrics for the nested trial are the level of uptake of CBT-HA and the rate of follow-up. / Ethics and dissemination: Approved by Leicester Central Research Ethics Committee (reference: 20/EM/0238). The results of the study will be published in peer-reviewed scientific journals. / Trial registration number: ISRCTN14973494

    Severe COVID anxiety among adults in the United Kingdom: cohort study and nested feasibility trial

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    BACKGROUND: People with severe COVID anxiety have poor mental health and impaired functioning, but the course of severe COVID anxiety is unknown and the quality of evidence on the acceptability and impact of psychological interventions is low. METHODS: People with severe COVID anxiety have poor mental health and impaired functioning, but the course of severe COVID anxiety is unknown and the quality of evidence on the acceptability and impact of psychological interventions is low. RESULTS: 204 (70.2%) of 285 people who took part in the cohort study completed the six month follow-up, for whom levels of COVID anxiety fell from 12.4 at baseline to 6.8 at six months (difference = -5.5, 95% CI = -6.0 to -4.9). Reductions in COVID anxiety were lower among older people, those living with a vulnerable person, those with lower baseline COVID anxiety, and those with higher levels of generalised anxiety and health anxiety at baseline. 36 (90%) of 40 participants enrolled in the nested feasibility trial were followed up at six months. 17 (80.9%) of 21 people in the active arm of the trial received four or more sessions of CBT-HA. We found improved mental health and social functioning among those in the active, but not the control arm of the trial (Mean difference in total score on the Work and Social Adjustment Scale between baseline and follow up, was 9.7 (95% CI = 5.8–13.6) among those in the active, and 1.0 (95% C.I. = -4.6 to 6.6) among those in the control arm of the trial. CONCLUSIONS: While the mental health of people with severe COVID anxiety appears to improve over time, many continue to experience high levels of anxiety and poor social functioning. Health anxiety is highly prevalent among people with severe COVID anxiety and may provide a target for psychological treatment. TRIAL REGISTRATION: Retrospectively registered at ISRCTN14973494 on 09/09/2021

    Markers of serotonergic function in the orbitofrontal cortex and dorsal raphé nucleus predict individual variation in spatial-discrimination serial reversal learning.

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    Dysfunction of the orbitofrontal cortex (OFC) impairs the ability of individuals to flexibly adapt behavior to changing stimulus-reward (S-R) contingencies. Impaired flexibility also results from interventions that alter serotonin (5-HT) and dopamine (DA) transmission in the OFC and dorsomedial striatum (DMS). However, it is unclear whether similar mechanisms underpin naturally occurring variations in behavioral flexibility. In the present study, we used a spatial-discrimination serial reversal procedure to investigate interindividual variability in behavioral flexibility in rats. We show that flexibility on this task is improved following systemic administration of the 5-HT reuptake inhibitor citalopram and by low doses of the DA reuptake inhibitor GBR12909. Rats in the upper quintile of the distribution of perseverative responses during repeated S-R reversals showed significantly reduced levels of the 5-HT metabolite, 5-hydroxy-indoleacetic acid, in the OFC. Additionally, 5-HT2A receptor binding in the OFC of mid- and high-quintile rats was significantly reduced compared with rats in the low-quintile group. These perturbations were accompanied by an increase in the expression of monoamine oxidase-A (MAO-A) and MAO-B in the lateral OFC and by a decrease in the expression of MAO-A, MAO-B, and tryptophan hydroxylase in the dorsal raphé nucleus of highly perseverative rats. We found no evidence of significant differences in markers of DA and 5-HT function in the DMS or MAO expression in the ventral tegmental area of low- vs high-perseverative rats. These findings indicate that diminished serotonergic tone in the OFC may be an endophenotype that predisposes to behavioral inflexibility and other forms of compulsive behavior.This work was supported by Medical Research Council Grants (G0701500; G0802729), a 503 Wellcome Trust Programme Grant (grant number 089589/Z/09/Z), and by a Core Award 504 from the Medical Research Council and the Wellcome Trust to the Behavioural and Clinical 505 21 Neuroscience Institute (MRC Ref G1000183; WT Ref 093875/Z/10/Z). RLB was supported 506 by a studentship from the Medical Research Council. JA was supported by a Fellowship from 507 the Swedish Research Council (350-2012-230). BJ was supported by Fellowships from the 508 AXA Research Fund and the National Health and Medical Research Council of Australia. 509 Financial support from the Fredrik and Ingrid Thuring Foundation is also acknowledged.This is the accepted manuscript. The final version is available from Nature Publishing at http://www.nature.com/npp/journal/vaop/ncurrent/full/npp2014335a.html

    The NEWMEDS rodent touchscreen test battery for cognition relevant to schizophrenia.

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    RATIONALE: The NEWMEDS initiative (Novel Methods leading to New Medications in Depression and Schizophrenia, http://www.newmeds-europe.com ) is a large industrial-academic collaborative project aimed at developing new methods for drug discovery for schizophrenia. As part of this project, Work package 2 (WP02) has developed and validated a comprehensive battery of novel touchscreen tasks for rats and mice for assessing cognitive domains relevant to schizophrenia. OBJECTIVES: This article provides a review of the touchscreen battery of tasks for rats and mice for assessing cognitive domains relevant to schizophrenia and highlights validation data presented in several primary articles in this issue and elsewhere. METHODS: The battery consists of the five-choice serial reaction time task and a novel rodent continuous performance task for measuring attention, a three-stimulus visual reversal and the serial visual reversal task for measuring cognitive flexibility, novel non-matching to sample-based tasks for measuring spatial working memory and paired-associates learning for measuring long-term memory. RESULTS: The rodent (i.e. both rats and mice) touchscreen operant chamber and battery has high translational value across species due to its emphasis on construct as well as face validity. In addition, it offers cognitive profiling of models of diseases with cognitive symptoms (not limited to schizophrenia) through a battery approach, whereby multiple cognitive constructs can be measured using the same apparatus, enabling comparisons of performance across tasks. CONCLUSION: This battery of tests constitutes an extensive tool package for both model characterisation and pre-clinical drug discovery.This work was supported by the Innovative Medicine Initiative Joint Undertaking under grant agreement no. 115008 of which resources are composed of EFPIA in-kind contribution and financial contribution from the European Union’s Seventh Framework Programme (FP7/2007-2013). The authors thank Charlotte Oomen for valuable comments on the manuscript.This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s00213-015-4007-

    Antidepressant Controlled Trial For Negative Symptoms In Schizophrenia (ACTIONS): a double-blind, placebo-controlled, randomised clinical trial

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    BACKGROUND: Negative symptoms of schizophrenia represent deficiencies in emotional responsiveness, motivation, socialisation, speech and movement. When persistent, they are held to account for much of the poor functional outcomes associated with schizophrenia. There are currently no approved pharmacological treatments. While the available evidence suggests that a combination of antipsychotic and antidepressant medication may be effective in treating negative symptoms, it is too limited to allow any firm conclusions. OBJECTIVE: To establish the clinical effectiveness and cost-effectiveness of augmentation of antipsychotic medication with the antidepressant citalopram for the management of negative symptoms in schizophrenia. DESIGN: A multicentre, double-blind, individually randomised, placebo-controlled trial with 12-month follow-up. SETTING: Adult psychiatric services, treating people with schizophrenia. PARTICIPANTS: Inpatients or outpatients with schizophrenia, on continuing, stable antipsychotic medication, with persistent negative symptoms at a criterion level of severity. INTERVENTIONS: Eligible participants were randomised 1 : 1 to treatment with either placebo (one capsule) or 20 mg of citalopram per day for 48 weeks, with the clinical option at 4 weeks to increase the daily dosage to 40 mg of citalopram or two placebo capsules for the remainder of the study. MAIN OUTCOME MEASURES: The primary outcomes were quality of life measured at 12 and 48 weeks assessed using the Heinrich's Quality of Life Scale, and negative symptoms at 12 weeks measured on the negative symptom subscale of the Positive and Negative Syndrome Scale. RESULTS: No therapeutic benefit in terms of improvement in quality of life or negative symptoms was detected for citalopram over 12 weeks or at 48 weeks, but secondary analysis suggested modest improvement in the negative symptom domain, avolition/amotivation, at 12 weeks (mean difference -1.3, 95% confidence interval -2.5 to -0.09). There were no statistically significant differences between the two treatment arms over 48-week follow-up in either the health economics outcomes or costs, and no differences in the frequency or severity of adverse effects, including corrected QT interval prolongation. LIMITATIONS: The trial under-recruited, partly because cardiac safety concerns about citalopram were raised, with the 62 participants recruited falling well short of the target recruitment of 358. Although this was the largest sample randomised to citalopram in a randomised controlled trial of antidepressant augmentation for negative symptoms of schizophrenia and had the longest follow-up, the power of statistical analysis to detect significant differences between the active and placebo groups was limited. CONCLUSION: Although adjunctive citalopram did not improve negative symptoms overall, there was evidence of some positive effect on avolition/amotivation, recognised as a critical barrier to psychosocial rehabilitation and achieving better social and community functional outcomes. Comprehensive assessment of side-effect burden did not identify any serious safety or tolerability issues. The addition of citalopram as a long-term prescribing strategy for the treatment of negative symptoms may merit further investigation in larger studies. FUTURE WORK: Further studies of the viability of adjunctive antidepressant treatment for negative symptoms in schizophrenia should include appropriate safety monitoring and use rating scales that allow for evaluation of avolition/amotivation as a discrete negative symptom domain. Overcoming the barriers to recruiting an adequate sample size will remain a challenge. TRIAL REGISTRATION: European Union Drug Regulating Authorities Clinical Trials (EudraCT) number 2009-009235-30 and Current Controlled Trials ISRCTN42305247. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 29. See the NIHR Journals Library website for further project information

    Association between -T786C NOS3 polymorphism and resistant hypertension: a prospective cohort study

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    <p>Abstract</p> <p>Background</p> <p>It is estimated that 5% of the hypertensive patients are resistant to conventional antihypertensive therapy. Polymorphisms in the endothelial nitric oxide synthase (NOS3) gene have been associated with high blood pressure levels, but not with resistant hypertension. The aim of the present study was to investigate if the -786T>C and G894T (Glu298Asp) polymorphisms of the NOS3 gene were associated with resistant hypertension.</p> <p>Methods</p> <p>A prospective case-control observational study was performed. From a series of 950 consecutive patients followed up during 42 months, 48 patients with resistant hypertension were detected. 232 patients with controlled high blood pressure were also included.</p> <p>Results</p> <p>No differences were observed in the distribution of G894T (Glu298Asp) NOS3 genotypes between the resistant hypertension group and the controlled hypertension patients. However, genotype -786CC was more frequent in the group of patients with resistant hypertension (33.3%) than in the group of patients with controlled high blood pressure (17.7%) (p 0.03). Furthermore carriers of allele T (-786TC and -786TT) were more frequent in patients with controlled hypertension (82.3%) than those with resistant hypertension (66.7%) (Multivariate analysis; RR 2.09; 95% CI 1.03–4.24; p 0.004).</p> <p>Conclusion</p> <p>Our results indicate that genotype -786CC of the NOS3 gene increase the susceptibility to suffer resistant hypertension, which suggest that resistance to conventional therapy could be determined at the endothelial level.</p

    Synaptic scaffold evolution generated components of vertebrate cognitive complexity

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    The origins and evolution of higher cognitive functions, including complex forms of learning, attention and executive functions, are unknown. A potential mechanism driving the evolution of vertebrate cognition early in the vertebrate lineage (550 million years ago) was genome duplication and subsequent diversification of postsynaptic genes. Here we report, to our knowledge, the first genetic analysis of a vertebrate gene family in cognitive functions measured using computerized touchscreens. Comparison of mice carrying mutations in each of the four Dlg paralogs showed that simple associative learning required Dlg4, whereas Dlg2 and Dlg3 diversified to have opposing functions in complex cognitive processes. Exploiting the translational utility of touchscreens in humans and mice, testing Dlg2 mutations in both species showed that Dlg2\u27s role in complex learning, cognitive flexibility and attention has been highly conserved over 100 million years. Dlg-family mutations underlie psychiatric disorders, suggesting that genome evolution expanded the complexity of vertebrate cognition at the cost of susceptibility to mental illness
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