Investigating cognitive flexibility as a potential mechanism of mindfulness in Generalized Anxiety Disorder

Background and objectives

Research suggests mindfulness-based treatments may enhance efficacy of CBT for Generalized Anxiety Disorder (GAD). One hypothesized mechanism of mindfulness is cognitive flexibility; however, research findings to date are mixed as to a) whether cognitive inflexibility represents a characteristic of GAD, and b) whether mindfulness impacts cognitive flexibility. It is proposed that limitations in study methodology may partially account for these mixed findings. The present study investigated cognitive flexibility as a potential mechanism of mindfulness in a sample with elevated GAD symptoms using a modified emotional Stroop switching task while attempting to control for limitations of previous research. The purpose of the study was: 1) to explore cognitive inflexibility as a potential characteristic of GAD, and 2) to examine whether a brief mindfulness induction has measurable impact on cognitive flexibility.

Methods

A total of 66 participants (53 with elevated GAD symptoms, and 13 non-anxious) were randomized to a mindful-breathing, music-assisted relaxation, or thought wandering condition prior to completing an emotional Stroop and emotional Stroop switching task.

Results

Results suggest that GAD may be characterized by an inflexible style of responding, and exposure to mindfulness and relaxation result in partial improvements in cognitive flexibility.

Limitations

Limitations of this study include small sample size, brief induction period, and use of an analog sample.

Conclusions

The present findings suggest that mindfulness may be associated with partial improvement in cognitive flexibility.     

Glucose metabolism transporters and epilepsy: Only GLUT1 has an established role

The availability of glucose, and its glycolytic product lactate, for cerebral energy metabolism is regulated by specific brain transporters. Inadequate energy delivery leads to neurologic impairment. Haploinsufficiency of the glucose transporter GLUT1 causes a characteristic early onset encephalopathy, and has recently emerged as an important cause of a variety of childhood or later‐onset generalized epilepsies and paroxysmal exercise‐induced dyskinesia. We explored whether mutations in the genes encoding the other major glucose (GLUT3) or lactate (MCT1/2/3/4) transporters involved in cerebral energy metabolism also cause generalized epilepsies. A cohort of 119 cases with myoclonic astatic epilepsy or early onset absence epilepsy was screened for nucleotide variants in these five candidate genes. No epilepsy‐causing mutations were identified, indicating that of the major energetic fuel transporters in the brain, only GLUT1 is clearly associated with generalized epilepsy.     

Generalized Anxiety Disorder,Comorbid Major Depression and Heart Rate Variability: A Case-Control Study in Taiwan

Objective

Decreased heart rate variability (HRV) has been reported in generalized anxiety disorder (GAD), but the results are mixed. Little is known about the impact of comorbid major depression (MD) on HRV in GAD patients. Both issues necessitate further investigation.

Methods

Twenty unmedicated, physically healthy GAD patients, 20 GAD patients with a secondary diagnosis of MD, 40 MD patients and 60 matched controls were recruited. We used the Hamilton Anxiety Rating Scale and the Hamilton Depression Rating Scale to assess anxiety and depression severity, respectively. Cardiac autonomic function was evaluated by measuring HRV parameters. Frequency-domain indices of HRV were obtained.

Results

Three patient groups had more anxiety and depression symptoms than control subjects, but heart rates (HRs) were significantly elevated only in GAD patients with comorbid depression. Relative to controls, GAD patients had reduced HRV while GAD patients with comorbid depression displayed the greatest reductions in HRV among three patients groups. Correlation analyses revealed anxiety/depression severity significantly associated with HRs, variance, LF-HRV and HF-HRV. However, separately analyzing among individual groups and adjusting for HRV-associated covariables rendered the correlations non-significant.

Conclusion

Our results suggest that reduction in HRV is a psychophysiological marker of GAD and individuals with comorbid GAD and MD may be distinguished based on psychophysiological correlates (for example, HF-HRV) from non-comorbid GAD patients. Taken into account that comorbid depression may confer increased risks for cardiovascular events in GAD patients, this subgroup of GAD patients may benefit better from cardiovascular risk reduction strategies.     

Using video modeling on an iPad to teach generalized matching on a sorting mail task to adolescents with autism

Two multiple probe designs across three and four participants evaluated the effects of video modeling to teach a matching response (sorting mail) to seven adolescents with autism. Participants were instructed on one set of responses (five mail pieces) using video modeling, while concurrently monitoring two other sets for generalization effects. Results indicated that three participants learned their target set and generalized to the untrained sets, and two participants required an error correction procedure to achieve or approach mastery on their target set. Two participants did not acquire target sets with video based instruction. Data on setting generalization and maintenance are also provided for the participants who reached mastery. Participant variables that may relate to responding, limitations to the study, and directions for future research on video based instruction are discussed.     

枸橼酸坦度螺酮治疗首发广泛性焦虑疗效观察

目的：观察枸橼酸坦度螺酮治疗广泛性焦虑的疗效和不良反应,为临床治疗广泛性焦虑提供依据。方法92例广泛性焦虑患者按随机数字表法分为对照组和观察组,各46例。观察组采用枸橼酸坦度螺酮治疗,起始剂量15 mg／d,3 d后增加5 mg,至35 mg／d,平均剂量为（31．0±3．4） mg／d。对照组给予奥沙西泮治疗,根据患者睡眠情况,每天服用剂量不超过30 mg,服用2周后,给药剂量逐渐递减至停服。比较两组的临床疗效、汉密尔顿焦虑量表（ HAMA）评分和不良反应。结果治疗2周末两组HAMA评分差异有统计学意义（ t＝2．16,P＜0．05）。观察组总有效率为86．9％,对照组总有效率为82．6％,两组总有效率差异无统计学意义（χ^2＝0．33,P＞0．05）。对照组不良反应发生率为63．0％,观察组不良反应发生率为32．6％,两组不良反应发生率差异有统计学意义（χ^2＝8．58,P＜0．05）。结论枸橼酸坦度螺酮治疗广泛性焦虑的疗效与奥沙西泮相当,不良反应小。     

Comparative study of three methods of estimation of creatinine clearance in critically ill patients

Background

At the bedside, the reference method for creatinine clearance determination is based on the measurement of creatinine concentrations in urine and serum (mCrCl). Several models are available to calculate the creatinine clearance from the serum creatinine concentration. This observational survey aimed at testing the hypothesis that the proposed equations are unreliable to determine accurate creatinine clearance in patients admitted to intensive care unit (ICU).

Method

Creatinine clearance was determined by the use of mCrCl. Then, we compared three equations: Cockcroft-Gault (CG), Simplified Modification of Diet in Renal Disease (MDRDs), and Chronic Kidney Disease Epidemiology (CKD-EPI) in 156 consecutive patients within the first 24 hours after ICU admission. We tested the hypothesis that the three equations were equivalent. The agreement between the three equations was evaluated by linear regression and Bland and Altman analysis.

Results

Bland and Altman analysis showed similar agreement between the three equations. The biases and precisions were –4.8 ± 51, –1.3 ± 50, and 8.2 ± 44 for CG, MDRDs, and CKD-EPI equations, respectively (P > 0.05). The precisions were similar for the three equations (P > 0.05). The percentages of outliers at ± 30% were 44%, 45%, and 49% for CG, MDRDs, and CKD-EPI, respectively (P > 0.05).

Conclusion

Regarding the high percentage of outliers, the use of these equations cannot be recommended in ICU patients.     

Targeted Behavioral Therapy for childhood generalized anxiety disorder: A time-series analysis of changes in anxiety and sleep

This study examined the efficacy of Targeted Behavioral Therapy (TBT), a newly developed intervention targeting features of childhood generalized anxiety disorder (GAD). Using a time-series design, 4 children (7–12 years) with primary GAD were treated with TBT, which includes sleep improvement strategies, systematic desensitization for reducing intolerance of uncertainty, and in vivo exposures for anxiety. Diagnostic interviews and questionnaires were administered at baseline, post-treatment and 3 months follow-up. Anxiety symptoms and sleep characteristics/problems were rated weekly during a 4-week baseline and 14-weeks of treatment. Two children remitted at post-treatment and no child had a GAD diagnosis at follow-up. Child but not parent report revealed improvements in both worry and sleep. Despite improvements from pre- to post-assessment, considerable symptom fluctuation observed during the baseline period preclude conclusion that symptom changes are specifically attributable to the course of treatment. Overall, preliminary support is provided for the efficacy of TBT for childhood GAD.     

米氮平治疗广泛性焦虑症患者的临床疗效及对患者防御方式与生活质量的改变

目的研究米氮平对广泛性焦虑症的治疗效果,并探讨其对患者防御方式与生活质量的影响。方法对32例广泛性焦虑症患者给予米氮平治疗,于治疗前和第1、2、4、6周末利用汉密顿焦虑量表（HAMA）评估临床疗效,同时在治疗前和治疗第6周末进行防御方式（DSQ量表）和生活质量（SF-36量表）调查。结果32例广泛性焦虑症患者中痊愈21例（65．6％）,显著进步7例（21．9％）,有效4例（12．5％）,显效率达87．5％,有效率达100％。第1、2、4、6周末与治疗前相比,HAMA评分均具有显著性差异（P〈0.05）;不良反应较少。与治疗前相比,第6周末患者成熟型防御机制评分升高,不成熟型和中间型防御机制评分降低,差异均有统计学意义（P〈0.05）;生活质量评估中一般健康（GH）、精力（VT）、社会功能（SF）、情感职能（RE）、精神健康（MH）等评分也均升高（P〈0．05）。结论米氮平能快速有效地治疗广泛性焦虑症,而且能促进患者防御机制向成熟型转变,提高生活质量。