Jinyao Yi

The Cultural Shaping of Depression: Somatic Symptoms in China, Psychological Symptoms in North America?

The expectation that Chinese people present distress somatically is a central prediction of cultural psychopathology and has been the subject of considerable theoretical speculation. At the same time, empirical studies have been infrequent and have yielded mixed results. The authors examined symptom presentation in Chinese (n=175) and Euro-Canadian (n=107) outpatients, using spontaneous problem report, structured clinical interview, and symptom questionnaire methods. All 3 methods yielded cross-culturally equivalent somatic and psychological symptom subscales. Chinese outpatients reported more somatic symptoms on spontaneous problem report and structured clinical interview compared with Euro-Canadians, who in turn reported more psychological symptoms on all 3 methods. The relation between culture and somatic symptom presentation was mediated by a tendency toward externally oriented thinking. Difficulties with identifying emotions or describing them to others did not differ significantly across cultures, supporting a nonpathological interpretation of observed differences. Psychological symptom effects were larger and more consistent than somatic symptom effects; because other studies have confirmed the ubiquity of somatic presentations worldwide, these results suggest that Western psychologization may be more culturally specific than is Chinese somatization.

Amygdala hyperactivation and prefrontal hypoactivation in subjects with cognitive vulnerability to depression

The hopelessness theory (HT) of depression is a diathesis-stress theory which construes cognitive vulnerability (CV) to depression. Neuroimaging studies examining depression have implicated the amygdala as an important potential locus of dysfunction in the processing of salient threatening stimuli. However, little is known about neural activation in the brain of subjects with CV to depression. Medication-free major depressive disorder (MDD) subjects (N=29), never depressed subjects with CV (N=26), and demographically matched never depressed healthy control (HC) subjects (N=31) were scanned using functional magnetic resonance imaging (fMRI) while performing an emotional matching task. The MDD subjects showed elevated left amygdala responses and reduced left dorsolateral prefrontal cortex (dlPFC) activation levels relative to HC subjects. Similarly, CV subjects had greater activity in the amygdala bilaterally and lesser activation in the dlPFC bilaterally, relative to HC subjects. The present findings raise the possibility that cognitive vulnerability to depression might be characterized by hypoactivation of the prefrontal cortex and hyperactivation of the amygdala in response to emotional stimuli; our observations might provide a potential interpretation to explain the abnormalities in neural networks mediating cognitive modulation of emotions in individuals with cognitive vulnerability to depression.

Abnormal hippocampal BDNF and miR-16 expression is associated with depression-like behaviors induced by stress during early life.

Some environmental stressors lead to the onset of depression via inhibiting hippocampal BDNF expression, but other environmental stressors-induced depression exhibits no change in BDNF expression. The underlying mechanisms behind the divergence remain unknown. In this study, depression-like behaviors were induced in rats by maternal deprivation (MD) and chronic unpredictable stress (CUPS). Depression-like behaviors were tested by open field test, forced swimming test, and sucrose consumption test. BDNF and miR-16 expressions in the hippocampus were examined by real-time PCR. MD and CUPS rats crawled less distance, exhibited decreased vertical activity, and produced more fecal pellets than control rats in the open field test. However, MD rats crawled less distance and produced significantly less fecal pellets than CUPS rats. In the forced swimming and sucrose consumption tests, CUPS and MD rats exhibited longer floating time and consumed less sucrose than control rats, but MD rats exhibited shorter floating time and consumed less sucrose than CUPS rats. MD but not CUPS rats showed lower BDNF mRNA and higher miR-16 expression than control rats. In MD rats, BDNF mRNA expression negatively correlated with the expression of miR-16. BDNF expression positively correlated with the total distance rats crawled and vertical activity in the open field test while miR-16 expression negatively correlated the two behaviors. BDNF positively correlated with sucrose preference rate while miR-16 negatively correlated with sucrose preference rate of the sucrose consumption test. Our study suggests that MD and CUPS induced different depression-like behaviors in rats. Depression induced by MD but not CUPS was significantly associated with upregulation of miR-16 and possibly subsequent downregulation of BDNF in hippocampus.

First-Episode Medication-Naive Major Depressive Disorder Is Associated with Altered Resting Brain Function in the Affective Network

Background Major depressive disorder (MDD) has been associated with abnormal structure and function of the brains affective network, including the amygdala and orbitofrontal cortex (OFC). However, it is unclear if alterations of resting-state function in this affective network are present at the initial onset of MDD. Aims To examine resting-state function of the brains affective network in first-episode, medication-naive patients with MDD compared to healthy controls (HCs). Methods Resting-state functional magnetic resonance imaging (rs-fMRI) was performed on 32 first-episode, medication-naive young adult patients with MDD and 35 matched HCs. The amplitude of low-frequency fluctuations (ALFF) of the blood oxygen level-dependent (BOLD) signal and amygdala-seeded functional connectivity (FC) were investigated. Results Compared to HC, MDD patients showed reduced ALFF in the bilateral OFC and increased ALFF in the bilateral temporal lobe extending to the insular and left fusiform cortices. Enhanced anti-correlation of activity between the left amygdala seed and the left OFC was found in MDD patients but not in HCs. Conclusions Reduced ALFF in the OFC suggests hypo-functioning of emotion regulation in the affective network. Enhanced anti-correlation of activity between the amygdala and OFC may reflect dysfunction of the amygdala-OFC network and additionally represent a pathological process of MDD.

Psychopathology and neuropsychological impairments in deficit and nondeficit schizophrenia of Chinese origin.

Deficit schizophrenia is a relatively homogeneous subtype of patients which is considered helpful to explore the pathogenesis of schizophrenia. The aim of the present study was to reexamine the clinical characteristics of deficit (n=30) and nondeficit schizophrenia (n=93) in a Chinese sample and investigate the differences of neurocognitive function among the two subtypes of schizophrenia and the normal controls (n=103). Schizophrenia patients completed the Brief Psychiatric Rating Scale (BPRS), Scale for the Assessment of Negative Symptoms (SANS) and Scale for the Assessment of Positive Symptoms (SAPS). Additionally, all participants completed an abbreviated version of the Wechsler Adult Intelligence Scale (WAIS-RC) and a neuropsychological test battery examining the executive functions, visuospatial abilities and explicit memory related to the frontal, parietal, and temporal lobe functions. The deficit group received higher scores than the nondeficit group on the BPRS anergia factor and SANS affective flattening, alogia, avolition-apathy, anhedonia-asociality subscales, but not on the SAPS. Both two schizophrenia subgroups performed more poorly on the WAIS-RC and neuropsychological tests than the normal controls. Moreover, deficit patients performed worse than nondeficit patients on the prorated IQ, the Trail Making Test, Wisconsin Card Sorting test and Block Design test. The present study replicated symptom profiles in deficit vs. nondeficit schizophrenia in the Chinese sample. Furthermore, this study suggested that deficit schizophrenia is associated with frontal and parietal lobe impairment, and that temporal lobe dysfunction may be a common basis for cognitive impairment in schizophrenia as a whole.

Cognitive emotion regulation strategies as predictors of depressive symptoms in women newly diagnosed with breast cancer.

This study aimed to determine the effects of cognitive emotion regulation strategies on depressive symptoms in women with breast cancer.

Maternal deprivation enhances behavioral vulnerability to stress associated with miR-504 expression in nucleus accumbens of rats.

Objective In this study, the effect of maternal deprivation (MD) and chronic unpredictable stress (CUS) in inducing depressive behaviors and associated molecular mechanism were investigated in rats. Methods Maternal deprivation was established by separating pups from their mothers for 6 hours daily from postnatal day 1 to day 14. Chronic unpredictable stress was established by water deprivation, elevated open platform, food deprivation, restraint stress and electric foot shock. The depressive behaviors were determined by use of sucrose preference test and forced swim test. Results Rats in MD/CUS group exhibited lower sucrose preference rate, longer immobility time, and lighter body weights than rats in other groups (MD/control, non-MD/CUS and non-MD/control group). Meanwhile, higher miR-504 expression and lower dopamine receptor D1 (DRD1) and D2 (DRD2) expression were observed in the nucleus accumbens of rats in the MD/CUS group than in the other three groups. MiR-504 expression correlated negatively with DRD1 gene expression and sucrose preference rate in the sucrose preference test, but correlated positively with immobility time in forced swim test. Both DRD2 mRNA and protein expression correlated negatively with immobility time in forced swim test. Conclusion These results suggest that MD enhances behavioral vulnerability to stress during adulthood, which is associated with the upregulation of miR-504 and downregulation of DRD2 expression in the nucleus accumbens.

Increased structural connectivity in corpus callosum in adolescent males with conduct disorder

OBJECTIVE Adolescents with conduct disorder (CD) are at high risk for developing adult antisocial personality disorder. However, the underlying neuropathophysiology of CD remains poorly understood. We hypothesized that the microstructure of white matter (WM) of males with CD may differ from that of healthy control subjects (HCs). METHOD Tract-based spatial statistics (TBSS) and quantitative tractography were used to assess WM microstructural differences between 36 teenaged boys with CD and 33 demographically matched HCs. RESULTS The CD group behavioral scale scores were significantly higher than those of the HCs on the Barratt Impulsivity Scale, the Strength and Difficulties Questionnaire, and the Antisocial Process Screening Device total scales. TBSS revealed that, relative to HCs, the CD group had higher fractional anisotropy (FA) in the corpus callosum (CC) region, bilaterally, including the genu and body of the CC, as well as in some projection fibers in the region of the left anterior coronal radiate and right superior coronal radiate. Tractography confirmed higher FA of fibers passing through the regions with significant differences in the TBSS results. Exploratory analysis revealed that impulsivity associated positively with the FA of these fibers in the CD group. CONCLUSIONS Maturation of WM microstructure in CD subjects differed from that in HCs, mainly in the CC. The abnormal maturation of WM structures may play an important role in the impulsivity and aggression of teenagers with CD.

Sex differences of uncinate fasciculus structural connectivity in individuals with conduct disorder.

Conduct disorder (CD) is one of the most common behavior disorders in adolescents, such as impulsivity, aggression, and running from school. Males are more likely to develop CD than females, and two previous diffusion tensor imaging (DTI) studies have demonstrated abnormal microstructural integrity in the uncinate fasciculus (UF) in boys with CD compared to a healthy control group. However, little is known about changes in the UF in females with CD. In this study, the UF was illustrated by tractography; then, the fractional anisotropy (FA), axial diffusivity, mean diffusion, radial diffusivity (RD), and the length and number of the UF fiber bundles were compared between male and female patients with CD and between female patients with CD and female healthy controls, as well as between males with CD and healthy males. We found that males with CD showed significantly higher FA of the bilateral UF and significantly lower RD of the left UF when comparing with females with CD. Meanwhile, significantly higher FA and lower RD of the bilateral UF were also found in boys with CD relative to the male healthy controls. Our results replicated previous reports that the microstructural integrity of the UF was abnormal in boys with CD. Additionally, our results demonstrated significant gender effects on the UF of patients with CD, which may indicate why boys have higher rates of conduct problems than girls.

Inhibition dysfunction in depression: Event-related potentials during negative affective priming

The study aimed to investigate whether depressed patients show impairment of valence-dependent inhibition and its neurophysiological correlates. Event-related potentials (ERPs) were collected from 18 patients with unipolar depression and 18 normal controls during an affective negative priming task. A less effective inhibition in patients was specific for negative information. These behavioral effects were paralleled by ERP differences. In addition to the overall reduced P2 amplitude for negative trials and the overall reduced late positive component (LPC) amplitude for positive and negative trials in patients, ERP differences in different conditions for each group were also found. The patients showed reduced central-parietal P2 amplitude and shorter LPC latency in response to negative experimental targets, whereas the controls showed larger left central P2 amplitude and delayed LPC latency in response to negative experimental targets. No such effects were found for positive targets. These results suggest that the inhibition dysfunction of negative affect influences the earlier attention allocation stage and the later evaluation stage in depressed patients.