Haiyin Zhang

Psychometric Properties of the Chinese Version of the Perceived Stress Scale in Policewomen

Background The 10-item Perceived Stress Scale (PSS-10) is one of most widely used instruments to measure a global level of perceived stress in a range of clinical and research settings. This study was conducted to examine the psychometric properties of the Simplified Chinese version of the PSS-10 in policewomen. Methodology A total of 240 policewomen were recruited in this study. The Simplified Chinese versions of the PSS-10, the Beck Depression Inventory Revised (BDI-II), and the Beck Anxiety Inventory (BAI) were administered to all participants, and 36 of the participants were re-tested two weeks after the initial testing. Principal Findings The overall Cronbachs alpha was 0.86, and the test–retest reliability coefficient was 0.68. Exploratory Factor Analysis (EFA) yielded 2 factors with eigenvalues of 4.76 and 1.48, accounting for 62.41% of variance. Factor 1 consisted of 6 items representing “negative feelings”; whereas Factor 2 consisted of 4 items representing “positive feelings”. The item loadings ranged from 0.72 to 0.83. The Confirmatory factor analysis (CFA) indicated a very good fit of this two-factor model to this sample. The PSS-10 significantly correlated with both BDI-II and BAI, indicating an acceptable concurrent validity. Conclusions The Simplified Chinese version of the PSS-10 demonstrated adequate psychometric properties for evaluating stress levels. The results support its use among the Chinese population.

Complexity measure and complexity rate information based detection of ventricular tachycardia and fibrillation

On the basis of non-linear dynamics, the paper uses a Lempel-Ziv complexity measure and presents a new definition of the information complexity rate: cc(n). Using such a definition, relative properties are obtained to help identify chaotic process accurately. Applying complexity analysis to abnormal ECGs recorded from patients with an implantable cardioverter defibrillator, the reasonableness of this information complexity and complexity rate approach are confirmed by means of biological experiments and computer simulations. Finally, objective analysis and explanations of the mechanisms of VT and VF are reported. The results indicate that, with the help of the complexity measure and complexity rate, recognition of ventricular tachycardia (VT) and ventricular fibrillation (VF) signals can be achieved with accuracy up to 100% (VT: 100%; VF: 98.7%).

Cross-sectional comparison of the clinical characteristics of adults with early-onset and late-onset obsessive compulsive disorder.

BACKGROUND Age at onset (AAO) in obsessive compulsive disorder (OCD) may differentiate genetically and clinically heterogeneous subtypes. The current cross-sectional study compared the characteristics of early-onset OCD (onset age≤18 years) and late-onset OCD (onset age>18 years). The AAO cut-off was based on the onset distribution observed in our systematically recruited patients with OCD. METHODS Six hundred and two (including 339 men and 263 women) outpatients meeting DSM-IV criteria of OCD were recruited from the Shanghai Mental Health Center and were screened by a battery of instruments: Yale-Brown Obsessive Compulsive Scale (YBOCS) attached Y-BOCS Symptom Checklist, Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Rating Scale (HAMA), and State-Trait Anxiety Inventory (STAI). The demographic and clinical characteristics of the 275 early-onset patients were compared to those of the 327 late-onset patients. RESULTS Compared to patients with late-onset OCD, early-onset patients with OCD were significantly more likely to be male (66.9% vs. 47.4%, X2=23.1, p<0.001), to have a positive family history of mental illnesses (26.5% vs. 19.0%, X2=4.9, p=0.026), and to have a longer duration of illness [80.0 (SD=80.7) vs. 65.5 (SD=78.3) months, t600=3.17, p=0.002]. Early-onset patients also had significantly higher scores on the HAMA, HAMD, STAI2, and obsessive in Y-BOCS. The sexual and symmetry/exactness obsessions and the washing/cleaning compulsions were significantly more prevalent in the early-onset group. CONCLUSIONS The study of a large sample from mainland China confirms the findings from previous studies and supports the hypothesis that early-onset OCD is a demographically and clinically distinct subtype of OCD.

Negative affect mediates effects of psychological stress on disordered eating in young Chinese women.

Background The bi-relationships between psychological stress, negative affect and disordered eating has been well studied in western culture, while tri-relationship among them, i.e. how some of those factors influence these bi-relationships, has rarely been studied. However, there has been little related study in the different Chinese culture. This study was conducted to investigate the bi-relationships and tri-relationship between psychological stress, negative affect, and disordered eating attitudes and behaviors in young Chinese women. Methodology A total of 245 young Chinese policewomen employed to carry out health and safety checks at the 2010 Shanghai World Expo were recruited in this study. The Chinese version of the Perceived Stress Scale (PSS-10), Beck Depression Inventory Revised (BDI-II), Beck Anxiety Inventory (BAI), and Eating Attitude Test (EAT-26) were administered to all participants. Principal Findings The total scores of PSS-10, BDI-II and BAI were all highly correlated with that of EAT-26. The PSS-10 score significantly correlated with both BDI-II and BAI scores. There was no statistically significant direct effect from perceived stress to disordered eating (–0.012, 95%CI: –.038∼0.006, p = 0.357), however, the indirect effects from PSS-10 via affect factors were statistically significant, e.g. the estimated mediation effects from PSS to EAT-26 via depression and anxiety were 0.036 (95%CI: 0.022∼0.044, p<0.001) and 0.015 (95%CI: 0.005∼0.023, p<0.01), respectively. Conclusions Perceived stress and negative affects of depression and anxiety were demonstrated to be strongly associated with disordered eating. Negative affect mediated the relationship between perceived stress and disordered eating. The findings suggest that effective interventions and preventative programmes for disordered eating should pay more attention to depression and anxiety among the young Chinese female population.

BDNF Val66Met polymorphism and plasma levels in Chinese Han population with obsessive-compulsive disorder and generalized anxiety disorder.

BACKGROUND Anxiety disorders are a category of mental disorders characterized by feelings of anxiety and fear, which include generalized anxiety disorder (GAD). Obsessive-Compulsive Disorder (OCD) used to be categorized as anxiety disorder in DSM-IV. However OCD was no longer included in anxiety disorders and came into its own category titled as Obsessive-Compulsive and Related Disorders (OCRD) in DSM-5. It will be interesting to explore is there any different biological characteristics between OCD and anxiety disorders. Brain-derived neurotrophic factor (BDNF) was a potential candidate gene in both OCD and GAD. The results of genetic association studies between BDNF and OCD have been inconsistent. BDNF plasma/serum levels in OCD have been found lower than those in healthy controls. However the heritable reason of the lowered BDNF levels was not well elucidated. The amount of studies about BDNF and GAD were relatively small. The aims of this study were to determine whether single nucleotide polymorphism Val66Met of BDNF was associated with OCD and GAD, to examine BDNF plasma levels in OCD and GAD, and to explore whether Val66Met variation influences BDNF plasma levels. METHODS We genotyped Val66Met variation in 148 OCD patients, 108 GAD patients and 99 healthy controls. Within the same sample, BDNF plasma levels were determined in 113 OCD patients, 102 GAD patients and 63 healthy controls. RESULTS Val66Met variation was not associated with OCD or GAD. BDNF plasma levels in OCD and GAD patients were significant lower than those in healthy controls. Val66Met variation had no influence on BDNF plasma levels. No difference was found between OCD and GAD. Results do not change no matter taking OCD and GAD as one group or separated two. LIMITATIONS First, the sample size for genotyping was relatively small, which leaded to a low statistical power of the genetic part in this study. Second, we genotyped just one SNP in BDNF gene. Third, parts of the participants did not be assayed for BDNF plasma levels. CONCLUSIONS Our findings support the hypothesis that BDNF is involved in the pathophysiology of mental disorders, not only OCD but also GAD. OCD and GAD patients both show lower BDNF plasma levels compared to healthy controls. The BDNF plasma levels are not associated with Val66Met variation.

Altered intrinsic insular activity predicts symptom severity in unmedicated obsessive-compulsive disorder patients: a resting state functional magnetic resonance imaging study

BackgroundPrevious neuroimaging data indicated that the dysfunction in cortico-striato-thalamo-cortical (CSTC) circuit contributed to the neuropathological mechanism of obsessive-compulsive disorder (OCD). Whereas, emerging work has shown that the pathophysiology of OCD might be related to more widely distributed large-scale brain systems including limbic system and the salience network. This study aims to investigate the aberrant spontaneous neuronal activity within the whole brain, and its association with the symptom severity for unmedicated OCD patients.MethodTwenty-eight unmedicated OCD adults and twenty-eight matched healthy controls were recruited for a resting state functional magnetic resonance imaging (fMRI) study. The amplitude of low-frequency fluctuation (ALFF) analysis over whole brain was performed to examine the intrinsic cerebral activity of subjects. In addition, we conducted the voxel-based Pearson’s correlative analysis to probe into the relationship between ALFF values and symptom severity for OCD patients.ResultsOur results showed that OCD patients had increased ALFF measures in the left frontopolar cortex and left orbital frontal cortex (OFC), with decreased ALFF values in the right insula. Moreover, the right insular intrinsic activity was significantly correlated with total YBOCS score (r = 0.611, p = 0.002) and compulsion score (r = 0.640, p = 0.001) for OCD patients.ConclusionThe results showed abnormal intrinsic neuronal activity within CSTC circuit and salience network of OCD patients. Our finding of aberrant insular activity advanced the understanding of OCD pathophysiology beyond the traditional CSTC circuit. To the best of our knowledge, it is the first finding about a reduced insular activity at the resting state for unmedicated OCD patients, which might serve as an informative biomarker for OCD pathophysiology.

Decreased thalamic glutamate level in unmedicated adult obsessive-compulsive disorder patients detected by proton magnetic resonance spectroscopy.

BACKGROUND Previous neuroimaging studies implied that the dysfunction of cortico-striato-thalamo-cortical (CSTC) circuit served as the neural basis for the pathophysiology of obsessive-compulsive disorder (OCD). The imbalances in neuronal metabolite and neurotransmitter within CSTC circuit have been shown as the leading reasons of the OCD onset. The aim of this study is to investigate the metabolic alterations, especially the glutamatergic signal dysfunction within CSTC circuit, and the relationships between neural metabolites and the symptom severity of OCD patients. METHODS Single voxel magnetic resonance spectroscopy (MRS) was conducted in medial prefrontal cortex (mPFC) and bilateral thalamus areas for thirteen unmedicated adult OCD patients with age-, gender-, and education-matched healthy controls. Quantification and multivariate analysis were performed to identify vital metabolic biomarkers for patients and healthy controls group differentiation. Moreover, we performed Spearman׳s rank correlation analysis for OCD patients to examine the relationship between the metabolite concentration level and OCD symptomatology. RESULTS Patients with OCD showed significantly decreased glutamate level in mPFC (p=0.021) and right thalamus (p=0.039), and significantly increased choline compounds in left thalamus (p=0.044).The glutamate in right thalamus was shown as the most important metabolite for group separation from multivariate analysis (Q(2)=0.134) and was significantly correlated with the patients׳ compulsion scores (Spearman r=-0.674, p=0.016). LIMITATIONS Limited sample size, the use of creatine and phosphocreatine (Cr) ratios rather than absolute concentrations and unresolved glutamine (Gln) are limitations of the present study. CONCLUSION Our study results consolidated the hypothesis about glutamatergic signaling dysfunction in OCD. To our knowledge, it is the first finding about a reduced thalamic glutamate level in adult unmedicated OCD patients. The dysregulation of glutamate serves as a potential target for the OCD pharmacotherapy and the detailed mechanisms underlying the glutamate alterations within CSTC circuits merit further investigations.

Dopamine receptor D2 and catechol-O-methyltransferase gene polymorphisms associated with anorexia nervosa in Chinese Han population: DRD2 and COMT gene polymorphisms were associated with AN

Dopamine receptor D2 (DRD2) and catechol-O-methyltransferase (COMT) are important in dopamine system which is proved to be associated with food-anticipatory behavior, food restriction, reward and motivation. This has made them good candidates for anorexia nervosa (AN). The aim of this work is to explore the roles of DRD2 (rs1800497) and COMT (rs4680, rs4633, rs4818) gene polymorphisms in the susceptibility of AN within the Chinese Han population. We recruited 260AN patients with DSM-IV diagnosis criteria, and 247 unrelated, normal weight controls. DRD2 (rs1800497) and COMT (rs4680, rs4633, rs4818) were genotyped in all subjects. We found rs1800497 and rs4633 were associated with the susceptibility of AN within the Chinese Han sample, and allele C of rs1800497 was a protective factor. There was a gene-gene interaction between rs1800497 of DRD2 gene and rs4633 of COMT gene. We concluded that rs1800497 and rs4633 play important roles in the AN susceptibility with respect to the Chinese Han population. The gene-gene interaction between DRD2 and COMT contributes to the risk of AN.

Spontaneous neuronal activity in insula predicts symptom severity of unmedicated obsessive compulsive disorder adults.

Emerging evidence has suggested that the pathophysiology of obsessive compulsive disorder (OCD) might involve widely distributed large-scale brain systems. The dysfunction within salience network, which is comprised of dorsal anterior cingulated cortex (dACC) and bilateral insular areas, has been proposed to contribute to OCD onset. The mechanism underlying salience network abnormality remains unclear and it is worthwhile to investigate its clinical relevance using functional neuroimaging approaches. In this study, we performed the spontaneous brain activity measurement using resting-state functional magnetic resonance imaging (fMRI) on unmedicated OCD patients (n=23). Specifically, the amplitude of low frequency (0.01-0.08 Hz) fluctuations (ALFF) was calculated for regions in salience network. The voxel-based Pearsons correlative analysis was conducted to explore the relationship beween ALFF measures and symptom severity for OCD patients. The results showed that the spontaneous neuronal activity in insula was significantly correlated to OCD clinical symptoms, especially compulsive behaviors. Our findings consolidated that the salience network played an important role in the pathogenesis of OCD and the intensity of intrinsic brain activity in insula provided a predictive biomarker for OCD symptom severity.

Intrinsic functional connectivity alteration of dorsal and rostral anterior cingulate cortex in obsessive-compulsive disorder: a resting fMRI study

Cortico-striato-thalamo-cortical (CSTC) circuit has been implicated in OCD pathophysiology by converging neuroimaging findings. The anterior cingulate cortex (ACC), as an important part within CSTC circuit, plays a critical role in OCD etiology. The ACC can be divided into dorsal and rostral parts anatomically, which are involved in cognitive process and emotional function, respectively. However, the diverse function of intrinsic signals from dorsal and rostral ACC regions remains unclear in OCD study. In this work, we applied resting-state functional magnetic resonance imaging (rs-fMRI) technology to investigate and differentiate the functional connectivity (FC) characteristics between dACC and rACC in unmedicated OCD patients. Also, the correlation between the altered FC and clinical symptom severity was analyzed. Decreased FC of rACC-DLPFC and increased FC between dACC and caudate were found. Moreover, the altered dACC-caudate FC was positively correlated with total Y-BOCS and compulsion score in OCD patients. Our findings implied the crossed function of dorsal and rostral circuits in the pathophysiologic mechanism of OCD. The dorsal cingulate-striatum functional pathway served as a potential biomarker for OCD symptomatology and merits further investigations.