Affective outcomes of virtual reality exposure therapy for anxiety and specific phobias: a meta-analysis

Virtual reality exposure therapy (VRET) is an increasingly common treatment for anxiety and specific phobias. Lacking is a quantitative meta-analysis that enhances understanding of the variability and clinical significance of anxiety reduction outcomes after VRET. Searches of electronic databases yielded 52 studies, and of these, 21 studies (300 subjects) met inclusion criteria. Although meta-analysis revealed large declines in anxiety symptoms following VRET, moderator analyses were limited due to inconsistent reporting in the VRET literature. This highlights the need for future research studies that report uniform and detailed information regarding presence, immersion, anxiety and/or phobia duration, and demographics.     

Neural mechanisms of automatic and direct processing of phobogenic stimuli in specific phobia.

BACKGROUND: The study aimed to identify brain activation during direct and automatic processing of phobogenic stimuli in specific phobia. METHODS: Responses to phobia-related and neutral pictures (spiders and mushrooms) were measured by means of event-related functional magnetic resonance imaging during two different tasks. In the identification task, subjects were asked to identify the object (spider or mushroom). In a demanding distraction task, subjects had to match geometric figures displayed in the foreground of the pictures. RESULTS: Phobics showed greater responses to spiders versus mushrooms in the left amygdala, left insula, left anterior cingulate gyrus (ACC), and left dorsomedial prefrontal cortex (DMPFC) during the identification task and in the left and right amygdala during the distraction task. All of these activations were also significantly increased compared to control subjects who did not show stronger brain activation to spiders versus mushrooms under any task condition. CONCLUSIONS: Our findings propose specific neural correlates of automatic versus direct evaluation of phobia-relevant threat. While the amygdala, especially the right amygdala, seems to be crucially involved in automatic stimuli processing, activation of areas such as the insula, ACC and DMPFC is rather associated with direct threat evaluation and requires sufficient attentional resources.     

The anatomy of fear learning in the cerebellum: A systematic meta-analysis

Recent neuro-imaging studies have implicated the cerebellum in several higher-order functions. Its role in human fear conditioning has, however, received limited attention. The current meta-analysis examines the loci of cerebellar contributions to fear conditioning in healthy subjects, thus mapping, for the first time, the neural response to conditioned aversive stimuli onto the cerebellum. By using the activation likelihood estimation (ALE) technique for analyses, we identified several distinct regions in the cerebellum that activate in response to the presentation of the conditioned stimulus: the cerebellar tonsils, lobules HIV–VI, and the culmen. These regions have separately been implicated in fear acquisition, consolidation of fear memories and expression of conditioned fear responses. Their specific role in these processes may be attributed to the general contribution of cerebellar cortical networks to timing and prediction. Our meta-analysis highlights the potential role of the cerebellum in human cognition and emotion in general, and addresses the possibility how deficits in associative cerebellar learning may play a role in the pathogenesis of anxiety disorders. Future studies are needed to further clarify the mechanistic role of the cerebellum in higher order functions and neuropsychiatric disorders.     

Comorbidity of panic disorder with agoraphobia and specific phobia: Relationship with the subtypes of specific phobia

The study objectives were to determine comorbidity rates for various subtypes of specific phobia (SP) in a sample of patients with the principal diagnosis of panic disorder with agoraphobia (PDA) and to examine the possible etiologic relatedness of these SP subtypes to PDA. Ninety consecutive day clinic patients with PDA were administered the Structured Clinical Interview for DSM-III-R (SCID) modified for DSM-IV. The overall comorbidity rate for SP was 65.6%. The most frequent subtypes of SP were situational phobia and dental phobia, followed by natural environment phobia, phobia of funerals, cemeteries, dead bodies, and other death-related phenomena and objects (referred to as death-related phobia), and blood-injection-injury phobia. Except for death-related phobia, other subtypes of SP clearly tended to precede the onset of PDA, often by many years. The Smallest difference between the age of onset for PDA and particular subtypes of SP (temporal distance) was found for death-related phobia, whereas the temporal difference was longer for situational phobia, hospital phobia, and blood-injection-injury phobia. The frequency and temporal distance data suggest that death-related phobia may constitute a risk factor for developing PDA or that it is a prodrome of PDA, whereas situational phobia, hospital phobia, and blood-injection-injury phobia appear to predispose to PDA to a lesser degree. Of the three broadly conceived groups of SP, mutilation phobias (which include death-related phobia, hospital phobia, blood-injection-injury phobia, and dental phobia) appear most etiologically relevant for PDA, with the group of situational phobias (which also includes the natural environment subtype of SP) being less relevant, and animal phobias showing a negligible etiologic relatedness to PDA.     

The heritability of melatonin secretion and sensitivity to bright nocturnal light in twins

The super-sensitivity of the neurohormone melatonin to light in patients with bipolar disorder provides evidence of the circadian nature of the disorder. This response has been proposed as an endophenotype for identifying people at risk of the disorder and guiding investigations of molecular genetic targets. However, before this response is used as an endophenotypic marker, the heritable nature of melatonin sensitivity in the normal population must be established. The aim of this study was to investigate the heritability of nocturnal melatonin secretion and sensitivity to light in monozygotic and dizygotic twins with no psychiatric history. This study investigated overall melatonin levels (between 2000 and 2400 h) and suppression by 500 lx of light (between 2400 and 0100 h) in 20 pairs of twins (nine monozygotic, 11 dizygotic). The results indicate that melatonin secretion is highly heritable with secretion in one twin being a significant predictor of secretion in their twin in both monozygotic and dizygotic pairs. In relation to light sensitivity, genetic loading appears to play a significant role with the greatest concordance between monozygotic twins, followed by dizygotic twins and finally low concordance in unrelated individuals. This provides additional support for the usefulness of melatonin sensitivity to light as a potential endophenotypic marker of bipolar affective disorder.     

Fear-relevant illusory correlations in different fears and anxiety disorders: A review of the literature

Fearful individuals often overestimate the relationship between fear-relevant stimuli and aversive consequences. Such fear-relevant illusory correlations (ICs) might be involved in the maintenance of anxiety disorders. In this literature review, we found clear evidence that ICs are present and enhanced in fear of animals. We also revealed some evidence for ICs related to fear of flying, social anxiety, contamination fear, panic disorder, and post-traumatic stress disorder, but with considerably less clarity. Fear-relevant ICs seem to be best explained by both a priori expectancies and biased encoding of the experienced associations. Studies to date suggest that one important biased encoding process is the enhanced aversiveness/salience of fear-relevant outcomes. Future studies may improve insight by developing more reliable IC measures and testing the effect of encoding processes on treatment outcomes.     

A population-based study on phobic fears and DSM-IV specific phobia in 70-year olds

This population-based study reports on the prevalence and characteristics of specific phobia (SP) and phobic fears in an elderly population. A representative population sample of Swedish 70-year-olds without dementia (N = 558) was examined using semi-structured interviews. Phobic fears included fear of animals, natural environment, specific situations, blood-injection-injury and ‘other’. Mental disorders, including SP, were diagnosed according to DSM-IV. Phobic fears (71.0% vs. 37.9%) and SP (13.8% vs. 4.5%) were more common in women than in men. Among those with phobic fears, more than 80% reported onset before age 21. Of those with SP, 35.7% had another DSM-IV diagnosis compared to 8.5% of those reporting no fear. Fear of specific situations and ‘other’ fears were related to SP and other anxiety disorders. SP was related to lower global functioning. We conclude that specific phobia in the elderly should receive attention from health professionals as it is common and associated with a decrease in global functioning.     

A systematic review and meta-analysis of the incidence and severity of postoperative fatigue

OBJECTIVE: Postoperative fatigue is common following major abdominal surgery. Less is known about its prevalence in other surgical subgroups, and about its long-term prognosis. A systematic review of prospective cohort studies was conducted to clarify these issues. METHOD: Studies were identified from an extensive literature search. Overall estimates of pre- to postoperative change in fatigue severity and the incidence of clinically significant postoperative fatigue were calculated using meta-analyses. RESULTS: Eighty-one cohorts were identified. Type of surgery was found to be a possible predictor of fatigue severity, with major abdominal, gynaecological, cardiac and minor surgery apparently associated with greater fatigue than orthopaedic surgery. Limited data were available regarding the long-term persistence of postoperative fatigue. CONCLUSION: Postoperative fatigue appears to be an important problem following only certain forms of surgery. Why this is so remains unclear, and further work using better fatigue questionnaires is now required to confirm these differences.     

Social anxiety disorder and quality of life: How fears of negative and positive evaluation relate to specific domains of life satisfaction

Individuals with social anxiety disorder (SAD) experience functional impairment in social, educational, and occupational arenas, contributing to poor quality of life. Previous research using the Quality of Life Inventory (QOLI) has identified four distinct domains of quality of life among individuals with SAD: Achievement, Personal Growth, Social Functioning, and Surroundings. The present study was designed to investigate how fear of negative evaluation (FNE) and fear of positive evaluation (FPE) relate to the four QOLI domains among individuals with SAD. We also examined the relationships of FNE and FPE to Satisfaction and Importance ratings on the QOLI. Individuals with SAD (N = 129) completed a battery of questionnaires prior to initiating treatment. FNE and FPE showed distinct relationships with the four QOLI domains, even after controlling for demographic characteristics and comorbid depression. Both FNE and FPE were associated with ratings of Satisfaction with the QOLI domains, but neither was associated with ratings of Importance. Our findings highlight the differential impacts of FNE and FPE on SAD. Treatment implications are discussed.     

Genetic and environmental causes of variation in adolescent anxiety symptoms: A multiple-rater twin study

Heritability estimates for adolescent anxiety vary across studies, partly depending on who is rating the symptoms. The goal of our study was to estimate genetic and environmental influences using a multi-informant design with responses from a population-based sample of adolescent twins, their mothers and their fathers (N = 1394 families).Results from multivariate biometrical modeling indicated quantitative, but no qualitative sex differences in etiology. The best fitting model was an AE Common Pathway model, defining anxiety as a latent factor common to all informants. This model offers error free estimates of genetic and environmental influences explaining the latent factor variance.Variation in the latent factor was highly genetic, with heritability estimates of 65% for boys and 74% for girls. Non-shared environmental effects explained the remaining variance. In addition, there were significant rater-specific genetic and environmental effects for both sexes.The observed rater differences underline the importance of using several informants when studying adolescent anxiety.     

Split hand in amyotrophic lateral sclerosis: A systematic review and meta-analysis

ObjectiveTo investigate the frequency of split hand (SI) and its diagnostic performance in amyotrophic lateral sclerosis (ALS).MethodsPubMed, EMBASE, OVID and other databases were searched systematically up to March 2021 for relevant reports about the split hand syndrome. Two reviewers screened and selected the titles and abstracts of the studies independently during the database searches and performed full-text reviews and extracted available data. In our study, AA_CMAP was calculated by AA_CMAP = APB_CMAP/ADM_CMAP and split-hand index (SI) was calculated by SI_CMAP = (APB_CMAP × FDI_CMAP)/ADM_CMAP. The mean differences (MD) in APB/ADM_CMAP and SI_CMAP between patients with ALS and control group were calculated (APB the abductor pollicis brevis muscle; ADM the abductor digiti minimi muscle; CMAP compound muscle action potentials). Meta-analysis was performed to determine summary sensitivity, specificity, and area under the curve (AUC) with 95% confidence intervals (CI) for SI_CMAP.ResultsPooled results of five studies including 339 patients showed that 50% (95%CI: 35%–65%) of patients with ALS presented split hand. APB/ADM_CMAP in patients with ALS was significantly lower than healthy population (MD: −0.38, 95%CI: −0.48, −0.28). SI_CMAP in patients with ALS was significantly lower than healthy controls (MD: −5.87, 95%CI: −6.28, −5.46) and neuromuscular controls (MD: −5.60, 95%CI: −5.78, −5.42). Receiver operating characteristic curve analysis showed that the AUC was 0.860 [95%CI: 0.808, 0.911] for SI_CMAP. The sensitivity and specificity for SI_CMAP were 78% and 81% (cut-off value: 5.2–11.8), respectively.ConclusionHalf of ALS patients might show split hand sign. SI_CMAP could be a potential biomarker in the diagnosis of ALS.     

The association between insomnia and the risk of metabolic syndrome: A systematic review and meta-analysis

ObjectiveThe purpose of this study was to perform a systematic review and meta-analysis on the association between insomnia and the risk of developing into metabolic syndrome (including hypertension, hyperglycemia, hyperlipidemia and obesity).MethodWe conducted our research according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta Analyses). After the search term was determined, we searched Pubmed and Embase databases until December 1, 2020 for the observational studies. We used random effects models to aggregate risk estimates for individual studies and the odds ratio (OR) as well as 95% confidence intervals (CI) were calculated for pooled data. Heterogeneity in this study was assessed by using I² statistic.Results12 studies were eventually included in this meta-analysis which contained metabolic syndrome related symptoms (hypertension, hyperglycemia, hyperlipidemia and obesity). The combined OR value and 95% CI of the hypertension group was 1.41 (1.19–1.67). The hyperglycemia group was 1.29 (1.11–1.50). The hyperlipidemia group was 1.12 (0.92–1.37) and the obesity group was 1.31 (1.03–1.67).ConclusionThe risk of insomnia patients suffering from hypertension, hyperglycemia, hyperlipidemia and obesity in metabolic syndrome was 1.41 times, 1.29 times and 1.31 times than people without insomnia respectively.     

Cognitive motor interference while walking: A systematic review and meta-analysis

Dual-task methodology has been increasingly used to assess cognitive motor interference while walking. However, whether the observed dual-task-related gait changes are systematically related to methodological variations remains unclear and researchers still lack knowledge of what cognitive task to use in different groups for clinical purposes or for research. We systematically reviewed experimental studies that measured gait performance with and without performing concurrent cognitive task. Our results suggest that cognitive tasks that involve internal interfering factors seem to disturb gait performance more than those involving external interfering factors. Meta-analysis results show that the overall effect of different cognitive tasks was prominent in gait speed. In healthy participants, meta-regression analysis suggests strong associations between age and speed reduction under dual-task conditions and between the level of cognitive state and speed reduction under dual-task conditions. Standardizing research methodologies, as well as improving their ecological validity, enables better understanding of dual-task-related gait changes in different populations and improves, in turn, our understanding of neural mechanisms and gait control in general in content.     

首发精神分裂症的遗传率及发病相关因素的研究

目的 了解精神分裂症的遗传率及其子女的预期发病率,并探讨其发病危险因素。方法 在山东省４７万人群中进行为期５年的前瞻性观察,选择首发精神分裂症患者,并进行１：２病例对照。结果 发现首发精神分裂症患者２０４例,选择对照４０８人。精神分裂症患者一、二级亲属的同病率均高于正常对照组（Ｐ〈０．０５）;精神分裂症的遗传率为６７．７２％,子女预期发病率为４．３％,精神分裂症的发病与阳性家族史、生活事件及家族环     

Association of birth weight with risk of autism: A systematic review and meta-analysis

BackgroundLow birth weight (LBW) has been reported to be a risk environmental factor for autism. However, the effects of normal birth weight (NBW) and macrosomia on autism have not been fully explored. This meta-analysis was conducted to explore the association between different birth weight levels and autism.MethodA systematic search was conducted in PubMed, Embase, and Scopus prior to April 26, 2020.ResultsA total of 28 studies were recognized as eligible. A significantly increased risk of autism was observed in relation to LBW (OR = 1.63, 95 % CI = 1.48–1.81, P < 0.00001) and macrosomia (OR = 1.11, 95 % CI = 1.05–1.18, P = 0.0005). NBW was found to be associated with a reduced risk of autism (OR = 0.74, 95 % CI = 0.67−0.82, P < 0.00001).ConclusionsLBW and macrosomia may increase the risk of autism, whereas NBW may reduce the risk of autism.     

A systematic review and meta-analysis of mindfulness-based stress reduction for the fibromyalgia syndrome

Objectives

This paper presents a systematic review and meta-analysis of the effectiveness of mindfulness-based stress reduction (MBSR) for FMS.

Methods

The PubMed/MEDLINE, Cochrane Library, EMBASE, PsychINFO and CAMBASE databases were screened in September 2013 to identify randomized and non-randomized controlled trials comparing MBSR to control interventions. Major outcome measures were quality of life and pain; secondary outcomes included sleep quality, fatigue, depression and safety. Standardized mean differences and 95% confidence intervals were calculated.

Results

Six trials were located with a total of 674 FMS patients. Analyses revealed low quality evidence for short-term improvement of quality of life (SMD = − 0.35; 95% CI − 0.57 to − 0.12; P = 0.002) and pain (SMD = − 0.23; 95% CI − 0.46 to − 0.01; P = 0.04) after MBSR, when compared to usual care; and for short-term improvement of quality of life (SMD = − 0.32; 95% CI − 0.59 to − 0.04; P = 0.02) and pain (SMD = − 0.44; 95% CI − 0.73 to − 0.16; P = 0.002) after MBSR, when compared to active control interventions. Effects were not robust against bias. No evidence was further found for secondary outcomes or long-term effects of MBSR. Safety data were not reported in any trial.

Conclusions

This systematic review found that MBSR might be a useful approach for FMS patients. According to the quality of evidence only a weak recommendation for MBSR can be made at this point. Further high quality RCTs are required for a conclusive judgment of its effects.     

对氧磷酶基因与阿尔茨海默病发病风险的Meta分析

目的使用系统评价方法评估对氧磷酶(paraoxonase,PON)基因与阿尔茨海默病(Alzheimer's disease,AD)发病的相关性。方法检索中英文数据库以发现合格研究,使用纽卡斯尔-渥太华量表(Newcastle-Ottawa Scale,NOS)评价纳入研究质量,采用随机或固定效应模型计算合并比值比(odds ratio,OR),使用Q检验评估研究之间的异质性,失安全系数、Egger's检验和漏斗图评估发表偏倚。结果总共15项研究符合Meta分析纳入标准。所有研究NOS评分均为7分以上,纳入研究质量较高。共涉及4个位点,最多一个位点(PON1Q192R)涉及11项研究,累计病例2366例和对照2579例。结果显示,PON2 S311C多态性SS基因型降低了总人群AD发病风险(OR=0.82,95%CI:0.68~0.99,P=0.04)。没有发现其它遗传多态性与AD具有相关性。结论现有证据表明,PON2 S311C多态性与AD发病风险具有相关性,本结论亟待大样本重复研究进一步验证。