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Schizophrenia Research. Cognition Jun 2022Cognitive impairments are core features of established schizophrenia spectrum disorders (SSD). However, it remains unclear whether specific cognitive functions are...
Cognitive impairments are core features of established schizophrenia spectrum disorders (SSD). However, it remains unclear whether specific cognitive functions are differentially impaired pre-onset and at what age these impairments can be detected. The purpose of this review was to elucidate these issues through a systematic summary of results from longitudinal studies investigating impairment in specific cognitive domains as antecedents of SSD. Relevant studies were identified by electronic and manual literature searches and included any original study of cognitive domains any time pre-onset of SSDs that included a control group. Effect sizes were calculated by domain for studies comparing high-risk participants who developed SSD with those who did not. The strongest evidence for impairment pre-onset was for mental processing speed, verbal learning and memory, executive function, and social cognition. Some verbal impairments, like language abilities at age 3 and verbal learning and memory at age 7, may develop as static deficits. Conversely, some non-verbal impairments, like mental processing speed, visuospatial abilities, and visual working memory manifest as developmental lag and become significant later in life. Most effect sizes were small to moderate, except for verbal fluency (d' = 0,85), implying this impairment as central in high-risk participants who develop SSD. The present review documents extensive cognitive impairments pre-onset of SSD, and that these impairments start early in life, in line with the neurodevelopmental hypothesis of schizophrenia. Increased knowledge about cognitive impairments preonset can provide a better basis for understanding the complex pathogenesis of SSD as well as informing cognitive remediation programs.
PubMed: 35251943
DOI: 10.1016/j.scog.2022.100246 -
Neuroscience and Biobehavioral Reviews Aug 2022The serotonergic system is involved in diverse cognitive functions including memory. Of particular importance to daily life are declarative memories that contain... (Review)
Review
The serotonergic system is involved in diverse cognitive functions including memory. Of particular importance to daily life are declarative memories that contain information about personal experiences, general facts, and events. Several psychiatric or neurological diseases, such as depression, attention-deficit-hyperactivity disorder (ADHD), and dementia, show alterations in serotonergic signalling and attendant memory disorders. Nevertheless, understanding serotonergic neurotransmission and its influence on memory remained a challenge until today. In this systematic review, we summarize recent psychopharmacological studies in animals and humans from a psychological memory perspective, in consideration of task-specific requirements. This approach has the advantage that comparisons between serotonin (5-HT)-related neurochemical mechanisms and manipulations are each addressing specific mnemonic circuits. We conclude that applications of the same 5-HT-related treatments can differentially affect unrelated tasks of declarative memories. Moreover, the analysis of specific mnemonic phases (e.g., encoding vs. consolidation) reveals opposing impacts of increased or decreased 5-HT tones, with low 5-HT supporting spatial encoding but impairing the consolidation of objects and verbal memories. Promising targets for protein synthesis-dependent consolidation enhancements include 5-HT receptor agonists and 5-HT receptor antagonists, with the latter being of special interest for the treatment of age-related decline. Further implications are pointed out as base for the development of novel therapeutic targets for memory impairment of neuropsychiatric disorders.
Topics: Animals; Attention Deficit Disorder with Hyperactivity; Cognition; Humans; Memory; Memory Disorders; Serotonin
PubMed: 35691469
DOI: 10.1016/j.neubiorev.2022.104729 -
The Cochrane Database of Systematic... May 2015People with fragile X syndrome (FXS) have an intellectual dysfunction that can range from very mild to severe. Symptoms can include speech and language delays and... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
People with fragile X syndrome (FXS) have an intellectual dysfunction that can range from very mild to severe. Symptoms can include speech and language delays and behavioural difficulties such as aggression or self injurious behaviours, emotional lability, and anxiety-related problems (for example obsessive-compulsive symptoms and perseverative behaviours). In some cases, affected people may have an additional diagnosis of attention deficit hyperactivity disorder or an autism spectrum disorder.
OBJECTIVES
To review the efficacy and safety of L-acetylcarnitine in improving the psychological, intellectual, and social performance of people with FXS.
SEARCH METHODS
In May 2015 we searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycINFO, Web of Science, and two other databases. We also searched three trials registers, four theses databases, and the reference lists of relevant studies and reviews.
SELECTION CRITERIA
Randomised controlled trials (RCTs) that assessed the efficacy of L-acetylcarnitine, at any dose, in people of any age diagnosed with FXS compared with placebo.
DATA COLLECTION AND ANALYSIS
For each trial, two review authors independently extracted data on the children included and interventions compared, and assessed the risk of bias of the studies across the following domains: randomisation sequence generation, allocation concealment, blinding (of participants, personnel, and outcome assessors), incomplete outcome data, selective outcome reporting, and other potential sources of bias.
MAIN RESULTS
We found only two RCTs that compared oral L-acetylcarnitine (LAC) with oral placebo in children with FXS. The studies included a total of 83 participants, all of them male, who were treated and followed for one year. The age of participants at the start of treatment ranged from 6 to 13 years, with a mean age of 9 years. Neither study provided information on randomisation, allocation concealment procedures, or blinding of outcome assessment, and we received no responses from the authors we emailed for clarification. We therefore rated studies as being at unclear risk of bias on these domains. We judged both studies to be at low risk of bias for blinding of participants and personnel, incomplete outcome data, and selective reporting, but to be at high risk of other bias, as at least one study was funded by a drug company, and in both studies people working for the company were part of the research team.We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to rate the quality of the available evidence. Overall, the quality of the evidence was low due to the imprecision of results and high risk of other bias.Regarding the primary outcome of psychological and learning capabilities, both studies assessed the effect of interventions on children's verbal and non-verbal intellectual functioning using the Wechsler Intelligence Scale for Children - Revised. The authors did not provide detailed data on those results but said that they found no important differences between treatment and placebo.Both studies evaluated the impact of the treatment on hyperactive behaviour using the Conners' Abbreviated Parent-Teacher Questionnaire. In one study, teachers' assessments of the children found no clear evidence of a difference (mean difference (MD) 0.50, 95% confidence interval (CI) -5.08 to 6.08, n = 51; low-quality evidence). The other study stated that there were no differences between treated and untreated participants, but did not provide detailed data for inclusion in the meta-analysis.Parents' assessments favoured LAC in one study (MD -0.57, 95% CI -0.94 to -0.19, n = 17; low-quality evidence), but not in the other (MD -2.80, 95% CI -7.61 to 2.01, n = 51; low-quality evidence), though changes were not large enough to be considered clinically relevant.Regarding social skills, one study reported no clear evidence of a difference in Vineland Adaptive Behavior composite scores (MD 8.20, 95% CI -0.02 to 16.42, n = 51; low-quality evidence), yet results in the socialisation domain favoured LAC (MD 11.30, 95% CI 2.52 to 20.08, n = 51; low-quality evidence).Both studies assessed the safety of the active treatment and recorded no side effects. Neither of the included studies assessed the secondary outcome of caregiver burden.
AUTHORS' CONCLUSIONS
Low-quality evidence from two small trials showed that when compared to placebo, LAC may not improve intellectual functioning or hyperactive behaviour in children with FXS.
Topics: Acetylcarnitine; Administration, Oral; Adolescent; Attention Deficit Disorder with Hyperactivity; Child; Fragile X Syndrome; Humans; Male; Randomized Controlled Trials as Topic; Vitamin B Complex
PubMed: 25985235
DOI: 10.1002/14651858.CD010012.pub2 -
MedEdPublish (2016) 2017This article was migrated. The article was marked as recommended. To increase the motivation of students at small group seminar education sessions, teachers and...
This article was migrated. The article was marked as recommended. To increase the motivation of students at small group seminar education sessions, teachers and institutions often revert to rewarding the prepared students and/or punishing those who did not prepare. How effective is that? We sought to find theoretical claims or disclaims for this policy from Self-Determination Theory, which is an important contemporary theory about motivation. SDT distinguishes intrinsic and extrinsic motivation and provides evidence for the use of rewards and punishments. The primary aim was to explore the effects of extrinsic rewards and negative incentives on the intrinsic motivation in the literature. A secondary goal was to provide practical tips for teachers to improve the motivation of medical students. Verbal rewards can increase the intrinsic motivation. Unexpected tangible and task-non-contingent tangible rewards appear to have no detrimental effect on the intrinsic motivation. All other expected tangible rewards and negative incentives, like threats and deadlines, have been found to undermine the intrinsic motivation. Autonomous self-regulated learning (intrinsic motivation, identified regulation and/or integrated regulation) is associated with high quality learning and well-being. Autonomous self-regulated learning is therefore the desired drive for learning and can be supported by a teacher via satisfying the needs for autonomy, competence and relatedness. Extrinsic rewards and negative incentives should be avoided as they both undermine the intrinsic motivation. Autonomous self-regulated learning leads to more effective learning. Several practical tips that support one of the three basic psychological needs are discussed. Most are relatively easy to apply and stimulate autonomous self-regulated learning.
PubMed: 38406451
DOI: 10.15694/mep.2017.000086 -
Psychiatria Danubina Sep 2022rTMS is an adequately safe intervention that is approved for treatment of various neuropsychiatric conditions. There is ongoing research on the application of rTMS for...
BACKGROUND
rTMS is an adequately safe intervention that is approved for treatment of various neuropsychiatric conditions. There is ongoing research on the application of rTMS for the treatment of resistant auditory verbal hallucinations (AVH) in schizophrenia (SZ), and also for alleviating negative and cognitive symptoms in patients with chronic SZ states. Language decline, as a part of thought, language and communication disorders, is one of the key symptoms of SZ, having a significant bearing on decreased social/interpersonal functioning of these patients. In this regard rTMS may be a promising treatment approach, while serving as an important research tool in the field of SZ studies. The aim of our present study was to compile and evaluate the existing data on whether rTMS affects verbal function in SZ patients, and if rTMS has any efficacy for the treatment of language disturbances in SZ spectrum disorders.
SUBJECTS AND METHODS
Our systematic search over the PubMed database revealed a total of 200 articles, of which 21 met criteria for inclusion in this analysis. We have reviewed in detail the study designs, inclusion and exclusion criteria, rTMS protocols and cognitive (in particular, speech/language domain) assessments reported in these articles.
RESULTS
The 21 studies focused on two key topic clusters: (i) low-frequency rTMS treatment of AVH in SZ, and (ii) high-frequency rTMS treatment of negative and cognitive SZ symptoms. The majority of study participants presented with chronic and treatment-resistant states. Most of the low-frequency rTMS studies did not show any difference in verbal test measures in SZ in response to treatment. Less than a half of high-frequency rTMS studies reported a delayed positive effect on language cognitive domains in SZ. There were sporadic reports on dropouts associated with a decline in scores for auditory verbal learning tests.
CONCLUSIONS
Our systematic review found rTMS to be generally safe in relation to verbal/speech function, and suggested that verbal memory tests could serve as a measure of safety of this treatment procedure in SZ patients. Speech effects of rTMS have only been registered over long-term observation periods, such that time-frame which should be considered as an important factor for future studies. In our project "Innovative Neuropsychiatry Research Bank: Priority-2030" we plan to clarify (i) efficient rTMS protocols targeting neurocognitive improvement in SZ, and (ii) the cohort of SZ patients with a particular cognitive endophenotype and language profile amenable to treatment with rTMS, with a focus on language scores.
Topics: Hallucinations; Humans; Language; Schizophrenia; Transcranial Magnetic Stimulation
PubMed: 36170724
DOI: No ID Found -
Journal of Neurology Aug 2016We conducted a systematic review of the literature and used meta-analytic techniques to evaluate the impact of shunt surgery on neuropsychological performance in... (Meta-Analysis)
Meta-Analysis Review
We conducted a systematic review of the literature and used meta-analytic techniques to evaluate the impact of shunt surgery on neuropsychological performance in patients with normal pressure hydrocephalus (NPH). Twenty-three studies with 1059 patients were identified for review using PubMed, Web of Science, Google scholar and manual searching. Inclusion criteria were prospective, within-subject investigations of cognitive outcome using neuropsychological assessment before and after shunt surgery in patients with NPH. There were statistically significant effects of shunt surgery on cognition (Mini-Mental State Examination; MMSE), learning and memory (Rey Auditory Verbal Learning Test; RAVLT, total and delayed subtests), executive function (backwards digit span, phonemic verbal fluency, trail making test B) and psychomotor speed (trail making test A) all in the direction of improvement following shunt surgery, but with considerable heterogeneity across all measures. A more detailed examination of the data suggested robust evidence for improved MMSE, RAVLT total, RAVLT delayed, phonemic verbal fluency and trail making test A only. Meta-regressions revealed no statistically significant effect of age, sex or follow-up interval on improvement in the MMSE. Our results suggest that shunt surgery is most sensitive for improving global cognition, learning and memory and psychomotor speed in patients with NPH.
Topics: Cerebrospinal Fluid Shunts; Cognition Disorders; Databases, Bibliographic; Humans; Hydrocephalus, Normal Pressure; Neuropsychological Tests
PubMed: 27017344
DOI: 10.1007/s00415-016-8097-0 -
Psychosomatic Medicine May 2023In past decades, the field of nocebo research has focused on studying how sensory perception can be shaped by learning. Nocebo effects refer to aggravated sensory... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
In past decades, the field of nocebo research has focused on studying how sensory perception can be shaped by learning. Nocebo effects refer to aggravated sensory experiences or increased sensitivity to sensations such as pain and itch resulting from treatment-related negative experiences. Behavioral conditioning and verbal suggestions of a negative treatment outcome may aggravate pain and itch perception. Gaining a comprehensive view of the magnitude of nocebo effects and contributing factors will help steer nocebo research toward fruitful directions for understanding complex sensory phenomena.
METHODS
We conducted a systematic review and meta-analysis of a total of 37 distinct experimental nocebo studies on healthy participants (all published in English between 2008 and 2021), with four separate meta-analyses for nocebo effects on pain or itch. We conducted subgroup analyses and meta-regression on factors such as type and intensity of sensory stimuli, and length of conditioning paradigms.
RESULTS
This meta-analysis showed that, on average, effect sizes of nocebo effects were moderate to large (Hedges g between 0.26 and 0.71 for the four primary outcomes). The combination of conditioning and verbal suggestions yielded stronger nocebo responses on pain in particular. Subgroup analyses, including factors such as the type of sensory stimulation, did not explain the moderate heterogeneity in nocebo magnitudes between different studies. Risk of bias was generally low and was not related to nocebo magnitudes either.
CONCLUSIONS
We discuss these results in relation to the role of conditioning and aversive learning, and we recommend more consistency in designing and reporting nocebo experiments.
Topics: Humans; Nocebo Effect; Placebo Effect; Pain; Learning; Pruritus
PubMed: 36961347
DOI: 10.1097/PSY.0000000000001194 -
Neuroscience and Biobehavioral Reviews Oct 2016Neurocognitive deficits are present in bipolar disorder (BD) patients and their unaffected (nonbipolar) relatives, but it is not clear which domains are most often... (Review)
Review
BACKGROUND
Neurocognitive deficits are present in bipolar disorder (BD) patients and their unaffected (nonbipolar) relatives, but it is not clear which domains are most often impaired and the extent of the impairment resulting from shared genetic factors. In this literature review, we address these issues and identify specific neurocognitive tasks most sensitive to cognitive deficits in patients and unaffected relatives.
METHOD
We conducted a systematic review in Web of Science, PubMed/Medline and PsycINFO databases.
RESULTS
Fifty-one articles assessing cognitive functioning in BD patients (23 studies) and unaffected relatives (28 studies) were examined. Patients and, less so, relatives show impairments in attention, processing speed, verbal learning/memory, and verbal fluency.
CONCLUSION
Studies were more likely to find impairment in patients than relatives, suggesting that some neurocognitive deficits may be a result of the illness itself and/or its treatment. However, small sample sizes, differences among relatives studied (e.g., relatedness, diagnostic status, age), and differences in assessment instruments may contribute to inconsistencies in reported neurocognitive performance among relatives. Additional studies addressing these issues are needed.
Topics: Attention; Bipolar Disorder; Cognition; Cognition Disorders; Humans; Neuropsychological Tests
PubMed: 27502749
DOI: 10.1016/j.neubiorev.2016.08.002 -
The International Journal of... Aug 2018We conducted a systematic review and meta-analysis of double-blind, randomized, placebo-controlled trials of anti-dementia drugs plus antipsychotics for schizophrenia. (Meta-Analysis)
Meta-Analysis
BACKGROUND
We conducted a systematic review and meta-analysis of double-blind, randomized, placebo-controlled trials of anti-dementia drugs plus antipsychotics for schizophrenia.
METHODS
Primary outcomes of efficacy and safety included improving overall symptoms (Positive and Negative Syndrome Scale and Brief Psychiatric Rating Scale scores) and all-cause discontinuation, respectively. Other outcomes included psychopathology subscales (positive, negative, general, and anxiety/depressive symptoms), cognitive function (attention/vigilance, reasoning/problem solving, social cognition, speed of processing, verbal learning, visual learning, working memory, and cognitive control/executive function), Mini-Mental State Examination scores, treatment discontinuation due to adverse events and inefficacy, and individual adverse events. We evaluated the effect size using a random effects model.
RESULTS
We identified 37 studies (n=1574): 14 donepezil-based (n=568), 10 galantamine-based (n=371), 4 rivastigmine-based (n=146), and 9 memantine-based (n=489) studies. Pooled anti-dementia drugs plus antipsychotics treatments were superior to placebo plus antipsychotics in improving the overall symptoms (24 studies, 1069 patients: standardized mean difference=-0.34, 95% CI=-0.61 to -0.08, P=.01), negative symptoms (24 studies, 1077 patients: standardized mean difference =-0.62, 95% CI=-0.92 to -0.32, Pcorrected=.00018), and Mini-Mental State Examination scores (7 studies, 225 patients: standardized mean difference=-0.79, 95% CI=-1.23 to -0.34, P=.0006). No significant differences were found between anti-dementia drugs plus antipsychotics and placebo plus antipsychotics regarding other outcomes.
CONCLUSIONS
Although the results suggest that anti-dementia drugs plus antipsychotics treatment improves negative symptoms and Mini-Mental State Examination scores in schizophrenia patients, they possibly were influenced by a small-study effect and some bias. However, it was not superior to placebo plus antipsychotics in improving composite cognitive test score, which more systematically evaluates cognitive impairment than the Mini-Mental State Examination score. Overall, the anti-dementia drugs plus antipsychotics treatment was well tolerated.
Topics: Cognition; Cognitive Dysfunction; Humans; Nootropic Agents; Randomized Controlled Trials as Topic; Schizophrenia; Schizophrenic Psychology; Treatment Outcome
PubMed: 29762677
DOI: 10.1093/ijnp/pyy045 -
Journal of Cancer Research and... 2020Whole-brain radiation therapy (WBRT) is an effective therapeutic modality in patients with brain metastases. However, nearly 90% of patients undergoing WBRT suffer from...
INTRODUCTION
Whole-brain radiation therapy (WBRT) is an effective therapeutic modality in patients with brain metastases. However, nearly 90% of patients undergoing WBRT suffer from a neurocognitive function (NCF) impairment at diagnosis, and up to two-thirds will experience a further decline within 2-6 months after WBRT. Focal-dose reduction on bilateral hippocampus is thought to improve NCF preservation. The aim was to present a systematic review of clinical results on NCF after hippocampal-sparing (HS) WBRT.
MATERIALS AND METHODS
A systematic review of published literature was performed on PubMed and the Cochrane Library. Only prospective clinical trials reporting NCF outcome in patients treated with HS-WBRT have been analyzed.
RESULTS
A total of 165 patients from three studies were included. These studies are characterized by small sample size and different methods in terms of WBRT technique but with similar planning analysis and NCF assessment tests. No significant changes in NCF (i.e., verbal and nonverbal learning memory, executive functions, and psychomotor speed) between baseline and 4-month follow-up after RT and only a mean relative decline in delayed recall at 4 months (7% compared to 30% of historical control) were observed.
CONCLUSIONS
Considering preliminary results on NCF preservation, further studies seem justified in patients undergoing brain irradiation for brain metastases or referred for prophylactic cranial irradiation to evaluate long-term effects on NCF and quality of life.
Topics: Brain Neoplasms; Cranial Irradiation; Hippocampus; Humans; Neurocognitive Disorders; Organ Sparing Treatments; Prognosis; Radiation Injuries
PubMed: 33342776
DOI: 10.4103/jcrt.JCRT_573_17