Comparison of resting-state spontaneous brain activity between treatment-naive schizophrenia and obsessive-compulsive disorder.

BACKGROUND: Schizophrenia (SZ) and obsessive-compulsive disorder (OCD) share many demographic characteristics and severity of clinical symptoms, genetic risk factors, pathophysiological underpinnings, and brain structure and function. However, the differences in the spontaneous brain activity patterns between the two diseases remain unclear. Here this study aimed to compare the features of intrinsic brain activity in treatment-naive participants with SZ and OCD and to explore the relationship between spontaneous brain activity and the severity of symptoms. METHODS: In this study, 22 treatment-naive participants with SZ, 27 treatment-naive participants with OCD, and sixty healthy controls (HC) underwent a resting-state functional magnetic resonance imaging (fMRI) scan. The amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo) and degree of centrality (DC) were performed to examine the intrinsic brain activity of participants. Additionally, the relationships among spontaneous brain activity, the severity of symptoms, and the duration of illness were explored in SZ and OCD groups. RESULTS: Compared with SZ group and HC group, participants with OCD had significantly higher ALFF in the right angular gyrus and the left middle frontal gyrus/precentral gyrus and significantly lower ALFF in the left superior temporal gyrus/insula/rolandic operculum and the left postcentral gyrus, while there was no significant difference in ALFF between SZ group and HC group. Compared with HC group, lower ALFF in the right supramarginal gyrus/inferior parietal lobule and lower DC in the right lingual gyrus/calcarine fissure and surrounding cortex of the two patient groups, higher ReHo in OCD group and lower ReHo in SZ group in the right angular gyrus/middle occipital gyrus brain region were documented in the present study. DC in SZ group was significantly higher than that in HC group in the right inferior parietal lobule/angular gyrus, while there were no significant DC differences between OCD group and HC group. In addition, ALFF in the left postcentral gyrus were positively correlated with positive subscale score (r = 0.588, P = 0.013) and general psychopathology subscale score (r = 0.488, P = 0.047) respectively on the Positive and Negative Syndrome Scale (PANSS) in SZ group. ALFF in the left superior temporal gyrus/insula/rolandic operculum of participants with OCD were positively correlated with compulsion subscale score (r = 0.463, P = 0.030) on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). The longer the illness duration in SZ group, the smaller the ALFF of the left superior temporal gyrus/insula/rolandic operculum (Rho = 0.-492, P = 0.020). The longer the illness duration in OCD group, the higher the ALFF of the right supramarginal gyrus/inferior parietal lobule (Rho = 0.392, P = 0.043) and the left postcentral gyrus (Rho = 0.385, P = 0.048), and the lower the DC of the right inferior parietal lobule/angular gyrus (Rho = - 0.518, P = 0.006). CONCLUSION: SZ and OCD show some similarities in spontaneous brain activity in parietal and occipital lobes, but exhibit different patterns of spontaneous brain activity in frontal, temporal, parietal, occipital, and insula brain regions, which might imply different underlying neurobiological mechanisms in the two diseases. Compared with OCD, SZ implicates more significant abnormalities in the functional connections among brain regions.

The Neural Correlates of the Abnormal Implicit Self-Esteem in Major Depressive Disorder: An Event-Related Potential Study.

Implicit self-esteem (ISE) has been considered a critical factor in the development and maintenance of major depressive disorder (MDD). Further investigating the event-related potential (ERP) characteristics underlying abnormal ISE in MDD would be helpful for understanding the neural mechanism of MDD. For this purpose, 32 MDD patients and 31 age- and sex-matched healthy controls (HCs) were enrolled in this study. The Rosenberg Self-Esteem Scale (RSES) was used to evaluate explicit self-esteem (ESE), and a self-esteem go/no-go association task (GNAT) was used to assess ISE. Electroencephalograms were synchronously recorded when performing the self-esteem GNAT. Behavioral data and ERP characteristics under different conditions were analyzed and compared within and across groups. The results showed that compared to HCs, MDD patients had significantly lower RSES scores and self-D scores of GNAT, which reflected lower levels of ESE and ISE, respectively. No significant correlation was found between RESE and self-D scores, and only RESE scores were significantly negatively correlated with the Hamilton Depression Rating Scale (HAMD) score. The averaged centroparietal go-P3 amplitude under the self-positive condition was significantly smaller in MDD than in HCs. Moreover, HCs had a significantly larger average centroparietal go-P3 amplitude in self-positive than in self-negative conditions, while this pattern was opposite in the MDD group. The neural activity patterns for other conditions were similar between MDD and HCs. Our results suggested that patients with MDD have a decreased level of both ESE and ISE, and ISE might be more independent of clinical symptoms. Decreased neural processing that implicitly associate self with positive conditions (and relatively increased implicit association between self and negative conditions) might be important neural correlates for abnormal ISE in MDD.

The neural correlates of interference control dysfunction of working memory in major depressive disorder: An event-related potential study.

Interference control function is a key function in a series of specific functions of working memory (WM), which is usually impaired in patients with major depressive disorder (MDD). Event-related potentials (ERPs) have advantages in exploring the neural processing of interference control and WM impairment, and therefore, it is helpful to further understand the neural mechanism of MDD. In the present study, 44 patients with MDD and 44 age- and sex-matched healthy controls (HCs) were recruited. All participants completed a 4-gradient difficulty Brown-Peterson task (BPT), whose difficulty was manipulated by changing the demand of interspersed distraction tasks. High-density EEG was simultaneously recorded. The hit rate and reaction time (RT) toward the target stimulus as well as the underlying ERP features were analyzed. The results showed that, when compared with HCs, MDD patients had significantly lower hit rates and longer RTs among all four difficulties of BPT. For ERP components, no significant between-group difference was found in either N100 or P200 average amplitudes; however, the centroparietal late positive potential (LPP) amplitude of both MDD group and HC group decreased with the increase of BPT difficulty, despite the pattern of the HC group was relative moderate. For both groups, the LPP amplitude was significantly smaller in high-order difficult BPT tasks than in low-order difficult tasks. Moreover, LPP amplitude in high-order difficult tasks was much smaller in MDD group than that of HC group. Our findings suggest that failure to control interference well may play a critical role in the impairment of WM in patients with MDD, and provided new evidence that the neural correlates of interference control dysfunction of WM in MDD.

Neural correlates of abnormal cognitive conflict resolution in major depression: An event-related potential study.

Abnormal cognitive conflict resolution has been considered as a critical element of executive dysfunctions inpatient with major depression (MD). Further clarifying whether there was a deficit at perceptual encoding stage or the early response-execution stage in conflict control function by event-related potential (ERP) technique in MD would be helpful in understanding the neural mechanism of MD. Participants included twenty-six depressed patients and twenty-six healthy controls (HCs). All participants measured with Hamilton Depression Scale (17-item edition, HAMD) and a Simon task. Electroencephalograms were synchronously recorded when performing the Simon task. The method of residue iteration decomposition was used to analyze the lateralized readiness potential (LRP) and P300 components, which contributed to divides ERP components into a stimulus-locked component (S-cluster), a response-locked component (R-cluster) and an intermediate component cluster (C-cluster) by using latency variability and time markers. Results showed that reactive times (RTs) for both groups were fastest in congruent trials, and slowest in incongruent trials; however, there is no difference in RTs under the three conditions between two groups. Accuracy Rate (ACC) for both groups were the highest in neutral trials, and the lowest in incongruent trials; ACC in MD group were all lower than that of HC group under three conditions. ERP data analyses showed that depressed patients had a deficit in activating the correct response, as reflected by reduced amplitudes of R-LRP, but no abnormality in LRP-S and P300-C. In conclusion, patients with MD present conflict control dysfunction (i.e., abnormal cognitive conflict resolution) at the early response-execution stage, not at perceptual encoding stage, which may be reflected by the reduced R-LRP amplitudes. The abnormal cognitive conflict resolution in activating the correct response might constitute an interesting treatment target.

The Neural Correlates of Effortful Cognitive Processing Deficits in Schizophrenia: An ERP Study.

Background: Individuals' information processing includes automatic and effortful processes and the latter require sustained concentration or attention and larger amounts of cognitive "capacity." Event-related potentials (ERPs) reflect all neural activities that are related to a certain stimulus. Investigating ERP characteristics of effortful cognitive processing in people with schizophrenia would be helpful in further understanding the neural mechanism of schizophrenia. Methods: Both schizophrenia patients (SCZ, n = 33) and health controls (HC, n = 33) completed ERP measurements during the performance of the basic facial emotion identification test (BFEIT) and the face-vignette task (FVT). Data of ERP components (N100, P200, and N250), BFEIT and FVT performances were analyzed. Results: Schizophrenia patients' accuracies of face emotion detection in the BFEIT and vignette emotion detection in the FVT were both significantly worse than the performance of the HC group. Repeated-measures ANOVAs performed on mean amplitudes and latencies revealed that the interaction effect for group × experiment × site (prefrontal, frontal, central, parietal, and occipital site) was significant for N250 amplitude. In FVT experiment, N250 amplitudes at prefrontal and frontal sites in schizophrenia group were larger than those of HC group; the maximum N250 amplitude was present at the prefrontal site in both the groups. For N250 latency, the interaction effect for group × experiment was significant; N250 latencies in the schizophrenia group were longer than those of the HC group. Conclusion: Schizophrenia patients present effortful cognitive processing dysfunctions which reflect in abnormal ERP components, especially N250 at prefrontal cortex and frontal cortex sites. These findings have important implications for further clarifying the neural mechanism of effortful cognitive processing deficits in schizophrenia.

Olanzapine-induced weight gain plays a key role in the potential cardiovascular risk: evidence from heart rate variability analysis.

Patients with schizophrenia have a higher risk for cardiovascular disease (CVD) than the general population. Research has suggested that autonomic imbalance is a common pathway to increased morbidity and mortality for CVD. Heart rate variability (HRV) analysis is a non-invasive method that assesses autonomic imbalance, and low HRV is correlated with high cardiovascular risk. Olanzapine, a widely used antipsychotic drug, is considered to have good cardiac safety because of not causing significant corrected QT-interval (QTc) prolongation; however, it is still unclear whether olanzapine affects HRV. We recruited 83 patients with schizophrenia who were medication-free for at least 1 month and tested their HRV at the baseline and 4 weeks after treatment with olanzapine. We found that patients who had substantial weight gain (EWG) manifested significantly lower HRV than those who had non-substantial weight gain (NWG) and that HRV decrease was positively correlated to an increase in body mass index (BMI) and weight gain. Our results indicate that olanzapine-induced weight gain may play an important role in its potential cardiovascular risk. Since olanzapine has a very high potential for weight gain compared with other antipsychotics, further research is needed to explore its cardiovascular safety profile, specifically long-term cardiac safety.

rs11098403 polymorphism near NDST3 is associated with a reduced risk of schizophrenia in a Han Chinese population.

A recent genome-wide association study indicated that rs11098403, a single nucleotide polymorphism in the vicinity of NDST3, was strongly associated with the risk of schizophrenia in Caucasians. However, this relation has not been validated in other populations or ethnic groups. Herein, we conducted a case-control study to investigate the association of rs11098403 polymorphism with the schizophrenia risk in a Han Chinese population comprising 440 schizophrenia patients and 450 control subjects. For the first time, we showed that the minor allele (G) of rs11098403 is closely associated with a reduced risk of schizophrenia (OR=0.614; 95% CI: 0.453-0.833; P=0.002; Power=0.832). Meanwhile, the G allele of rs11098403 seemed to reduce the schizophrenia risk via a dominant manner (GG+AG vs. AA, OR=0.526; 95% CI: 0.374-0.74; P<0.001). Furthermore, this association was further confirmed using an independent replication sample containing 267 schizophrenia patients and 400 control subjects with a Han Chinese descent (OR=0.652; 95% CI: 0.469-0.907; P=0.011; Power=0.772). Taken together, these findings demonstrate a significant association between rs11098403 and schizophrenia risk in Han Chinese, confirming the data that previously obtained from Caucasians.

An event-related potential investigation of deficient inhibitory control in individuals with pathological Internet use.

UNLABELLED: Zhou Z-H, Yuan G-Z, Yao J-J, Li C, Cheng Z-H. An event-related potential investigation of deficient inhibitory control in individuals with pathological Internet use. OBJECTIVE: The purpose of this study was to investigate deficient inhibitory control in individuals with pathological Internet use (PIU) using a visual go/no-go task by event-related potentials (ERPs). METHODS: Subjects were 26 individuals with PIU and 26 controls. Barratt Impulsiveness Scale-11 (BIS-11) was used for measures of impulsivity. A go/no-go task involved eight different two-digit numerical stimuli. The response window was 1000 ms and the inter-trial-interval (ITI) was 1500 ms. Electroencephalography (EEG) was recorded when participants performed the task. Brain electrical source analysis (BESA) 5.2.0 was used to perform data analysis and the no-go N2 amplitude was analysed for investigation of inhibitory control. RESULTS: BIS-11 total scores, attentional key and motor key scores in PIU group were higher than that of the control group. In the go/no-go task, false alarm rate of PIU group was higher, and hit rate was lower than that of the control group. A repeated measure ANOVA revealed a significant group, frontal electrode sites and group × frontal electrode sites main effect for N2 amplitudes of no-go conditions (for group: F = 3953, df = 1, p = 0.000; for frontal electrode sites: F = 541, df = 9, p = 0.000; for group × frontal electrode sites: F = 306, df = 9, p = 0.000), and a significant group, central electrode sites and group × central electrode sites main effect for N2 amplitudes of no-go conditions (for group: F = 9074, df = 1, p = 0.000; for central electrode sites: F = 163, df = 2, p = 0.000; for group × central electrode sites: F = 73, df = 2, p = 0.000). N2 amplitudes of no-go conditions were lower than those at control group. CONCLUSIONS: Individuals with PIU were more impulsive than controls and shared neuropsychological and ERPs characteristics of compulsive-impulsive spectrum disorder, which supports that PIU is an impulse disorder or at least related to impulse control disorder.

Effect of quetiapine on cognitive function in schizophrenia: a mismatch negativity potentials study.

OBJECTIVE: The purpose of this study was to investigate whether the effects of quetiapine on abnormalities of early auditory processing in patients with schizophrenia were reflected by mismatch negativity (MMN). METHODS: Subjects were 23 patients with schizophrenia and 23 controls. Psychopathology was rated in patients with the Positive and Negative Syndrome Scale (PANSS) at baseline and after 4-week and after 8-week treatments with quetiapine. Auditory stimuli for event-related potentials consisted of 100 ms/1000 Hz standards, intermixed with 100 ms/1500 Hz frequency deviants and 250 ms/ 1000 Hz duration deviants. A stimulus onset asynchrony of each was 300 ms. Electroencephalograph was recorded at Fz. BESA 5.1.8 was used to perform data analysis. MMN waveforms were obtained by subtracting waveforms elicited by standards from those elicited by frequency- or duration-deviant stimuli. RESULTS: Quetiapine decreased all PANSS scores. Patients showed smaller mean amplitudes of frequency and duration MMN at baseline than did controls. A repeated measure analysis of variance with sessions (i.e. baseline and 4- and 8-week treatments) and MMN type (frequency versus duration) as within-subject factors revealed no significant MMN type or MMN type × session main effect for MMN amplitudes (for MMN type: F = 0.704, df = 1, p = 0.403; for MMN type × session: F = 0.299, df = 2, p = 0.796). Session main effect was significant (F = 3.576, df = 2, p = 0.031). Least square difference tests showed significant differences between MMN amplitudes at 8 weeks and those at both baseline (p = 0.025) and 4 weeks (p = 0.020). MMN amplitudes at 8 weeks were higher than those at baseline. CONCLUSIONS: Quetiapine improved the amplitudes of MMN after the 8-week treatment. MMN offers objective evidence that treatment with the quetiapine may ameliorate preattentive deficits in schizophrenia.