Dampened motivation in schizophrenia: evidence from a novel effort-based decision-making task in social scenarios.

Apathy represents a significant manifestation of negative symptoms within individuals diagnosed with schizophrenia (SCZ) and exerts a profound impact on their social relationships. However, the specific implications of this motivational deficit in social scenarios have yet to be fully elucidated. The present study aimed to examine effort-based decision-making in social scenarios and its relation to apathy symptoms in SCZ patients. We initially recruited a group of 50 healthy participants (16 males) to assess the validity of the paradigm. Subsequently, we recruited 45 individuals diagnosed with SCZ (24 males) and 49 demographically-matched healthy controls (HC, 25 males) for the main study. The Mock Job Interview Task was developed to measure effort-based decision-making in social scenarios. The proportion of hard-task choice and a range of subjective ratings were obtained to examine potential between-group differences. SCZ patients were less likely than HC to choose the hard task with strict interviewers, and this group difference was significant when the hard-task reward value was medium and high. More severe apathy symptoms were significantly correlated with an overall reduced likelihood of making a hard-task choice. When dividing the jobs into two categories based on the levels of social engagement needed, SCZ patients were less willing to expend effort to pursue a potential offer for jobs requiring higher social engagement. Our findings indicated impaired effort-based decision-making in SCZ can be generalized from the monetary/nonsocial to a more ecologically social dimension. Our findings affirm the critical role of aberrant effort allocation on negative symptoms, and may facilitate the development of targeted clinical interventions.

Negative belief-updating bias for positive daily life events in individuals with schizophrenia and social anhedonia.

INTRODUCTION: Low-pleasure beliefs are found in both patients with schizophrenia (SZ) and individuals with high social anhedonia (SocAnh), and are associated with anhedonia. However, little is known about the development and maintenance of these low-pleasure beliefs in the clinical and subclinical populations. We investigated whether patients with SZ and individuals with high SocAnh have deficits in updating their beliefs, which may contribute to the understanding of the formation and maintenance of low-pleasure beliefs. METHODS: The Modified Belief Updating Task was administered to assess belief-updating patterns in a clinical sample (36 SZ patients and 30 matched controls) and a subclinical sample (27 individuals with high SocAnh and 30 matched controls). RESULTS: We found that compared with controls, SZ patients updated their beliefs to a greater extent and more frequently when receiving bad news for positive life events, but not for negative life events. Moreover, individuals with high SocAnh also exhibited similar patterns in updating their beliefs for positive life events after controlling depressive symptoms. CONCLUSIONS: Our findings suggest that negative belief-updating patterns for positive events may play an important role in the formation and maintenance of low-pleasure beliefs in patients with SZ and individuals with high SocAnh.

The remediation effects of working memory training in schizophrenia patients with prominent negative symptoms.

Introduction: Negative symptoms, particularly amotivation and anhedonia, are important predictors of poor functional outcome in patients with schizophrenia. There has been interest in the efficacy and mechanism of non-pharmacological interventions to alleviate these symptoms. The present study aimed to examine the remediation effect of working memory (WM) training in patients with schizophrenia with prominent negative symptoms.Methods: Thirty-one schizophrenia patients with prominent negative symptoms were recruited and assigned to either a WM training group or a treatment-as-usual (TAU) control group. The WM training group underwent 20 sessions of training using the dual n-back task over one month. A functional neuroimaging paradigm of the Affective Incentive Delay (AID) task was administered before and after the training intervention to evaluate the remediation effect of the intervention.Results: Our results showed that the WM training group demonstrated significant improvement in the WM training task and inattention symptoms. Compared with the TAU group, increased brain activations were observed at the right insula and the right frontal sub-gyral after WM training in the training group.Conclusions: These findings support the efficacy of WM training in ameliorating hedonic dysfunction in schizophrenia patients with prominent negative symptoms.

Contribution of long duration of undiagnosed bipolar disorder to high frequency of relapse: A naturalistic study in China.

BACKGROUND: With attention to misdiagnosis of bipolar disorder (BP), long duration of undiagnosed bipolar disorder (DUBP) had been reported recently in years. This study aims to investigate the contributions of long DUBP to the frequency of relapse in bipolar patients, and explore affect factors of DUBP. METHOD: From 26 hospitals throughout China, 3896 participants diagnosed with BP according to International Classification of Diseases 10th criteria were enrolled in this study. Socio-demographic and clinical data were collected from medical records and specific questionnaires through clinical interviews with patients and their relatives. RESULTS: (1) Our results showed that the mean of DUBP was 40.52months. In total, 779 patients (19.995%) reported DUBP greater than 5years, and 1931 patients (49.564%) reported their DUBP greater than 2years. The number of mood episodes was averaged 5.44, and the frequency ratio of (hypo) mania to depressive episodes was 1.49 (3.27/2.19). (2) Multiple linear regression analysis revealed that DUBP was significantly contributed to the number of relapse (Beta=0.072, p<0.001) after considering the confounding including gender, age at study entry, age of onset, age of first (hypo) manic episodes, age of first depressive episodes, type of first episodes and family history of mental illness. (3) Factors including age at the study entry (Beta=0.526, p<0.001), age of onset (Beta=-1.654, p<0.001), age of first (hypo) manic episode (Beta=0.348, p<0.001), age of first depressive episode (Beta=0.983, p<0.001), depression as the type of first episode (Beta=0.058, p<0.001) and family history of mental illness (Beta=0.029, p<0.05) were significantly contributed to long DUBP. CONCLUSION: It was concluded that long DUBP might lead to high frequent relapse in bipolar patients. The factors correlated with long DUBP include older age, early age of onset, depression as the type of first episode and family history of mental illness. The findings of our study suggest emergency task to early reorganization of bipolar disorder, and improving clinicians' recognition of bipolar disorder from patients with depressive episodes, especially in children and adolescents.

Range adaptive value representations in schizophrenia and major depression.

Anhedonia and amotivation are core symptoms of schizophrenia (SCZ) and major depressive disorder (MDD). Reward processing involves constructing and contrasting the representations for expected value (EV) and outcome value (OV) of a given stimulus, a phenomenon termed range adaptation. Impaired range adaptation can lead to anhedonia and amotivation. This study aimed to examine range adaptation in SCZ patients and MDD patients. Fifty SCZ, 46 MDD patients and 56 controls completed the Effort-based Pleasure Experience Task to measure EV and OV adaptation. SCZ and MDD patients showed altered range adaptation, albeit in different patterns. SCZ patients exhibited over-adaptation to OV and reduced adaptation to EV. By contrast, MDD patients exhibited diminished OV adaptation but intact EV adaptation. Both OV and EV adaptation were correlated with anhedonia and amotivation in SCZ and MDD. Taken together, our findings suggest that range adaptation is altered in both SCZ and MDD patients. Associations of OV and EV adaptation with anhedonia and amotivation were consistently found in SCZ and MDD patients. Impaired range adaptation in SCZ and MDD patients may be putative neural mechanisms and potential intervention targets for anhedonia and amotivation.

The network characteristics in schizophrenia with prominent negative symptoms: a multimodal fusion study.

Previous studies on putative neural mechanisms of negative symptoms in schizophrenia mainly used single modal imaging data, and seldom utilized schizophrenia patients with prominent negative symptoms (PNS).This study adopted the multimodal fusion method and recruited a homogeneous sample with PNS. We aimed to identify negative symptoms-related structural and functional neural correlates of schizophrenia. Structural magnetic resonance imaging (sMRI) and resting-state functional MRI (rs-fMRI) were performed in 31 schizophrenia patients with PNS and 33 demographically matched healthy controls.Compared to healthy controls, schizophrenia patients with PNS exhibited significantly altered functional activations in the default mode network (DMN) and had structural gray matter volume (GMV) alterations in the cerebello-thalamo-cortical network. Correlational analyses showed that negative symptoms severity was significantly correlated with the cerebello-thalamo-cortical structural network, but not with the DMN network in schizophrenia patients with PNS.Our findings highlight the important role of the cerebello-thalamo-cortical structural network underpinning the neuropathology of negative symptoms in schizophrenia. Future research should recruit a large sample and schizophrenia patients without PNS, and apply adjustments for multiple comparison, to verify our preliminary findings.

[A comparative study of N400 in generalized anxiety disorder versus obsessive compulsive disorder patients].

OBJECTIVE: To explore the features of events-related potentials (ERP) component N400 in generalized anxiety disorder (GAD) versus obsessive compulsive disorder (OCD) patients and understand the cognitive pattern and processing characteristic for Chinese characters. METHODS: ERP component N400 was recorded by Guangzhou Runjie WJ-1 ERP apparatus. And 41 GAD patients, 69 OCD patients and 58 normal controls (NC) were tested by the Chinese idioms ending with matching (congruent) or mismatching (incongruent) words. RESULTS: (1) Latencies: Significant differences were found of N400 latencies in ending words with the same pronunciation but different forms and meanings (NC: (377 ± 40) ms, OCD: (395 ± 43) ms, GAD: (396 ± 43) ms, congruent; NC: (415 ± 32) ms, OCD: (429 ± 35) ms, GAD: (430 ± 36) ms, incongruent), ending words with the same meaning but different pronunciations and forms (NC: (411 ± 32) ms, OCD: (424 ± 40) ms, GAD: (433 ± 39) ms, incongruent), ending words with different pronunciations, forms and meanings (NC: (399 ± 47) ms, OCD: (427 ± 53) ms, GAD: (434 ± 42) ms, congruent; NC: (442 ± 36) ms, OCD: (465 ± 35) ms, GAD: (474 ± 35) ms, incongruent) (P < 0.05 - 0.01). Compared with NC, the N400 latencies were prolonged in GAD and OCD patients. Compared with OCD patients, the GAD patients also showed prolonged N400 latencies in ending words with different pronunciations, forms and meanings (incongruent situation). (2) Significant differences were found of N400 amplitudes in ending words with the same pronunciation but different forms and meanings (NC: (9 ± 5) µV, OCD: (6 ± 5) µV, GAD: (6 ± 5) µV, congruent; NC: (11 ± 6) µV, OCD: (5 ± 4) µV, GAD: (6 ± 4) µV, incongruent), ending words with similar forms but different pronunciations and meanings (NC: (9 ± 5) µV, OCD: (5 ± 4) µV, GAD: (7 ± 5) µV, congruent; NC: (14 ± 6) µV, OCD: (6 ± 5) µV, GAD: (9 ± 7) µV, incongruent), ending words with different pronunciations, forms and meanings (NC: (9 ± 5) µV, OCD: (5 ± 4) µV, GAD: (5 ± 3) µV, congruent; NC: (14 ± 6) µV, OCD: (9 ± 7) µV, GAD: (9 ± 7) µV, incongruent) (P < 0.05 - 0.01). Compared with NC, N400 amplitudes decreased in GAD and OCD patients respectively. Compared with OCD patients, the GAD patients also showed elevated N400 amplitudes in ending words with similar forms but different pronunciations and meanings (congruent). CONCLUSION: The cognitive and emotional problems in GAD and OCD may be measured by N400 elicited by Chinese idioms. Notable N400 priming effects can be found in Chinese idioms.

Emotion Context Insensitivity is generalized in individuals with major depressive disorder but not in those with subclinical depression.

BACKGROUND: Depressed individuals experience deficits in emotional reactivity. One well-established theory is the Emotion Context Insensitivity (ECI) theory. To better understand impairments in emotional reactivity, we investigated whether the ECI theory is applicable to anticipatory, consummatory, and remembered affect, in both clinical and subclinical depression. METHODS: Participants were divided into four groups: Major Depressive Disorder Group (MDD, N = 60), Control Group for MDD (ControlMDD, N = 50), Subclinical Depression Group (SD, N = 56), and Control Group for SD (ControlSD, N = 56). The Hamilton Depression Rating Scale and the Beck Depression Inventory were used to assess the severity of depression and anhedonia symptoms. The Monetary Incentive Delay Task evaluated participants' affective responses towards monetary stimuli. RESULTS: The MDD group was more insensitive to both monetary reward and loss across most types of affect than was the control group. Compared with the controls, the SD group exhibited lower reactivity in anticipatory positive affect but enhanced reactivity in consummatory positive, anticipatory, and remembered negative affect. LIMITATIONS: Emotional affect was evaluated by subjective ratings, which may lack objectivity. Additionally, laboratory settings and monetary rewards used in this study may cause the results less generalized to daily life and to other types of rewards. CONCLUSION: The pattern of emotional reactivity in the MDD group was partly consistent with the ECI theory, whereas the SD group showed greater arousal and instability of emotional reactions. These different patterns could facilitate the understanding of emotional reactivity and develop further treatments across the course of depression.

Psychometric properties of the Dimensional Anhedonia Rating Scale in Chinese typical, subthreshold, and clinically depressed adolescents.

The Dimensional Anhedonia Rating Scale measures state anhedonia in multiple domains, such as hobbies, food and drink, social activities, and sensory experience, and it has good reliability and validity in adult samples. However, no study has examined the psychometrical properties of this scale in adolescents. The present study examined its reliability and validity in adolescents with and without depression. In Study 1, 988 high-school students completed the Dimensional Anhedonia Rating Scale; 915 completed the second-round survey 3 months later. Confirmatory factor analysis was used to determine the factor structure. Additionally, internal consistency and test-retest reliability, and concurrent, convergent, and divergent validity were assessed in typical adolescents. In Study 2, the Dimensional Anhedonia Rating Scale was administrated to 108 patients with major depressive disorder, 108 adolescents with subthreshold depression, and 108 healthy controls. Factor structure and convergent validity were assessed in the clinical and subclinical groups. Finally, a one-way analysis of variance (ANOVA) was applied to examine the effect of depression severity on the scale scores. The results of Study 1 indicated that a four-factor model (i.e., hobbies, food and drink, social activities, and sensory experience) best fit the data. Meanwhile, the scale also yielded good concurrent, convergent, and divergent validity, as well as high internal consistency and test-retest reliability, in typical adolescents. In Study 2, goodness-of-fit statistics also suggested a good fit for the four-factor model in the two depressed groups. The one-way ANOVA revealed significant group differences in the total and factor scores, whereby the major depressive disorder group had lower scores than the subthreshold depression group, whose scores were lower than the healthy controls, indicating excellent eligibility of the scale in depressed adolescents. The Chinese version of the Dimensional Anhedonia Rating Scale is a reliable and valid instrument to comprehensively measure state anhedonia in Chinese typical and depressed adolescents.

Amisulpride augmentation therapy improves cognitive performance and psychopathology in clozapine-resistant treatment-refractory schizophrenia: a 12-week randomized, double-blind, placebo-controlled trial.

BACKGROUND: Although clozapine is an effective option for treatment-resistant schizophrenia (TRS), there are still 1/3 to 1/2 of TRS patients who do not respond to clozapine. The main purpose of this randomized, double-blind, placebo-controlled trial was to explore the amisulpride augmentation efficacy on the psychopathological symptoms and cognitive function of clozapine-resistant treatment-refractory schizophrenia (CTRS) patients. METHODS: A total of 80 patients were recruited and randomly assigned to receive initial clozapine plus amisulpride (amisulpride group) or clozapine plus placebo (placebo group). Positive and Negative Syndrome Scale (PANSS), Scale for the Assessment of Negative Symptoms (SANS), Clinical Global Impression (CGI) scale scores, Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Treatment Emergent Symptom Scale (TESS), laboratory measurements, and electrocardiograms (ECG) were performed at baseline, at week 6, and week 12. RESULTS: Compared with the placebo group, amisulpride group had a lower PANSS total score, positive subscore, and general psychopathology subscore at week 6 and week 12 (PBonferroni < 0.01). Furthermore, compared with the placebo group, the amisulpride group showed an improved RBANS language score at week 12 (PBonferroni < 0.001). Amisulpride group had a higher treatment response rate (P = 0.04), lower scores of CGI severity and CGI efficacy at week 6 and week 12 than placebo group (PBonferroni < 0.05). There were no differences between the groups in body mass index (BMI), corrected QT (QTc) intervals, and laboratory measurements. This study demonstrates that amisulpride augmentation therapy can safely improve the psychiatric symptoms and cognitive performance of CTRS patients. CONCLUSION: This study indicates that amisulpride augmentation therapy has important clinical significance for treating CTRS to improve clinical symptoms and cognitive function with tolerability and safety. Trial registration Clinicaltrials.gov identifier- NCT03652974. Registered August 31, 2018, https://clinicaltrials.gov/ct2/show/NCT03652974.

Revisiting the latent structure of negative symptoms in schizophrenia: Evidence from two second-generation clinical assessments.

BACKGROUND: Negative symptoms are core symptom of schizophrenia, and many previous research studied the latent structure of negative symptoms based on a single measurement scale. Applying two second-generation negative symptom scales to the same sample can address measurement-invariance of latent structure. METHODS: Three-hundred-and-five schizophrenia patients were assessed using the CAINS and the BNSS. Confirmatory Factor Analysis (CFA) tested four competing factor-models: (1) a 1-factor model; (2) a 2-factor model comprising the motivation and pleasure (MAP) domain and the diminished expression (EXP) domain; (3) a 5-factor model comprising anhedonia, avolition, asociality, blunted affect and alogia; (4) a hierarchical model comprising the "first-order" 5-domain factors and the "second-order" MAP & EXP factors. RESULTS: The CFA results for the data of the CAINS showed that the 2-factor model had the best data fit over the other competing models. The CFA using the BNSS data in the same sample also supported the superiority of the 2-factor model. Lastly, after combining the items of the BNSS and CAINS together in the same sample for CFA, the 2-factor model prevailed over the other competing models. CONCLUSIONS: The 2-factor model appears to be measurement-invariant latent structure of negative symptoms. The novel method of combining the items of the CAINS and BNSS might have circumvented the possible imperfect construct of a single scale. Our findings support the MAP and EXP factors as the latent structure for negative symptoms.

[Clinical observation on treatment of major depressive disorder by paroxetine combined with chaihu xiaoyao mixture].

OBJECTIVE: To evaluate the efficacy and safety of Chaihu Xiaoyao Mixture (CXM) for the treatment of major depressive disorder (MDD). METHODS: One hundred and ninety patients with MDD were randomly assigned to two groups, the test group and the control group. They were treated by paroxetine combined with CXM or placebo for 8 weeks. The therapeutic efficacy was evaluated at the end of the 2nd, 4th and 8th week by scoring according Hamilton Rating Scale for Depression (HAMD-17) and Clinical Global Impression (CGI) scale, and the adverse reaction was scaled by Treatment Emergent Symptoms Scale (TESS). RESULTS: Follow-up study was completed in 89/92 patients in the test group, and 93/98 patients in the control group, with 3 and 5 cases dropping, respectively. The effective rate in the two groups was 84.8% and 71.4%, and the cure rate was 69.6% and 55.1%, respectively, which were significantly higher in the test group than in the control group (chi2=4.92, P<0.05; chi2=4.22, P<0.05). As compared with the baseline, significant differences in HAMD-17 total score and scores of its various factors as well as the CGI score were shown in both groups after 2, 4 and 8's week treatment (P<0.01). Comparison between groups showed that significant differences presented in HAMD-17 total score and CGI score at the end of the 8th week (P<0.01), while comparison of adverse reactions between groups showed insignificantly statistical difference (P>0.05). CONCLUSION: Combined treatment of CXM and paroxetine is more effective than that with paroxetine alone in treating MDD, and it could enhance the clinical efficacy with higher safety.

Revisiting anticipatory hedonic processing in patients with schizophrenia: An examination between representation activation and maintenance.

BACKGROUND: Anticipatory anhedonia is one of the key deficits found in patients with schizophrenia (SCZ). However, the underlying mechanism of this deficit remains unclear. The present study examined whether representation activation and maintenance capacity influenced anticipatory experiences in SCZ patients. METHODS: We recruited 46 SCZ patients (26 males) and 45 matched healthy controls (24 males). The Reward Representation Activation and Maintenance (RRAM) Task was administrated to assess anticipatory experience and representation activation and maintenance capacity. RESULTS: SCZ patients exhibited lower subjective arousal than controls in anticipation of rewards with high probability when representation activation and maintenance were difficult to accomplish. SCZ patients also tended to reduce their button presses more than HC when they were required to maintain reward representation. CONCLUSIONS: Our findings suggest that representation activation and maintenance may partially account for anticipatory anhedonia observed in SCZ patients.

Evidence in cortical folding patterns for prenatal predispositions to hallucinations in schizophrenia.

All perception is a construction of the brain from sensory input. Our first perceptions begin during gestation, making fetal brain development fundamental to how we experience a diverse world. Hallucinations are percepts without origin in physical reality that occur in health and disease. Despite longstanding research on the brain structures supporting hallucinations and on perinatal contributions to the pathophysiology of schizophrenia, what links these two distinct lines of research remains unclear. Sulcal patterns derived from structural magnetic resonance (MR) images can provide a proxy in adulthood for early brain development. We studied two independent datasets of patients with schizophrenia who underwent clinical assessment and 3T MR imaging from the United Kingdom and Shanghai, China (n = 181 combined) and 63 healthy controls from Shanghai. Participants were stratified into those with (n = 79 UK; n = 22 Shanghai) and without (n = 43 UK; n = 37 Shanghai) hallucinations from the PANSS P3 scores for hallucinatory behaviour. We quantified the length, depth, and asymmetry indices of the paracingulate and superior temporal sulci (PCS, STS), which have previously been associated with hallucinations in schizophrenia, and constructed cortical folding covariance matrices organized by large-scale functional networks. In both ethnic groups, we demonstrated a significantly shorter left PCS in patients with hallucinations compared to those without, and to healthy controls. Reduced PCS length and STS depth corresponded to focal deviations in their geometry and to significantly increased covariance within and between areas of the salience and auditory networks. The discovery of neurodevelopmental alterations contributing to hallucinations establishes testable models for these enigmatic, sometimes highly distressing, perceptions and provides mechanistic insight into the pathological consequences of prenatal origins.

Clinical utility of the dual n-back task in schizophrenia: A functional imaging approach.

The neural correlate of working memory (WM) impairment in schizophrenia is key to the understanding of the cognitive deficits observed in this disorder. We sought to determine the clinical validity of the dual version n-back paradigm in patients with schizophrenia, and whether schizophrenia patients exhibit altered brain activation patterns compared with healthy controls in this dual version WM measure using functional magnetic resonance imaging. Patients with schizophrenia (n = 20) and healthy controls (n = 24) performed the dual n-back task that consists of both visuospatial and auditory-verbal n-back streams, in which participants were required to monitor and update the contents from these two different inputs simultaneously. Significant positive correlations were found between performance in the dual 2-back condition and another measure of WM capacity and IQ estimates. Moreover, hypoactivation was observed at the right middle frontal gyrus and the posterior parietal regions in schizophrenia participants compared with healthy controls. The right hippocampus was less deactivated in schizophrenia patients compared with healthy controls. Our results support the clinical utility of the dual n-back task in schizophrenia and may have implications for the development of specific cognitive training targeting these impaired neural substrates in relation to WM in patients with schizophrenia.

Cross Cultural Validation and Extension of the Clinical Assessment Interview for Negative Symptoms (CAINS) in the Chinese Context: Evidence from a Spectrum Perspective.

The Clinical Assessment Interview for Negative Symptoms (CAINS) was designed in accordance with the recent theory and research in social affective neuroscience and to address the psychometric and conceptual limitations of other instruments assessing negative symptoms. The present study aimed to provide a large-scale validation of the CAINS in China and examine its applicability and validity evidence across the schizophrenia spectrum. Using confirmatory factor analysis, our results replicated the original findings in the US development samples that the CAINS possesses a stable 2-factor structure, namely "motivation/pleasure" and "expression". We also found significant correlations between the CAINS and other negative symptom measures. The CAINS demonstrated good discriminant validity in differentiating negative symptoms in people with schizophrenia, nonpsychotic first-degree relatives and people with social anhedonia. People with schizophrenia exhibited significantly higher CAINS subscale scores than first-degree relatives and healthy controls. In addition, first-degree relatives had higher "motivation/pleasure" scores than healthy controls. The "motivation/pleasure" subscale scores of individuals with social anhedonia were also significantly higher than healthy controls.

Striatal dysfunction in patients with schizophrenia and their unaffected first-degree relatives.

Despite empirical findings showing that patients with schizophrenia and their unaffected first-degree relatives have deficits in processing monetary incentives, it is unclear whether similar deficits could be demonstrated for affective incentives. Twenty-six patients with schizophrenia and 26 age and gender matched healthy controls; 23 unaffected first-degree relatives and 23 matched healthy controls were recruited to complete a Monetary Incentive Delay (MID) task and an Affective Incentive Delay (AID) task in a 3-Tesla MRI scanner. Hypoactivation in the dorsal striatum when anticipating monetary incentives were found in patients with schizophrenia and their unaffected first-degree relatives compared with healthy controls. Furthermore, patients with schizophrenia showed hyperactivation in the ventral striatum when receiving both monetary and affective incentives. These findings suggest that disorganized striatal function, regardless of incentive types, may be present in patients with schizophrenia and before the onset of illness in their first-degree unaffected relatives.

Suspiciousness in young minds: Convergent evidence from non-clinical, clinical and community twin samples.

BACKGROUND: We validated the Social Mistrust Scale (SMS) and utilized it to examine the structure, prevalence, and heritability of social mistrust in a large sample of Chinese children and adolescents. METHODS: In Study 1, a large sample of healthy twins (N=2094) aged 8 to 14years (M=10.27years, SD=2) completed the SMS. Structural equation modeling (SEM) was conducted to assess the structure of the SMS and to estimate the heritability of social mistrust in a sub-sample of twins (n=756 pairs). In Study 2, 32 adolescents with childhood-onset schizophrenia were compared with 34 healthy controls on levels of suspiciousness and clinical symptoms to examine the associations between the SMS and the Positive and Negative Syndrome Scale (PANSS). RESULTS: We found a three-factor structure for social mistrust (home, school, and general mistrust). Social mistrust was found to be moderately - heritable (19%-40%), with mistrust at home most strongly influenced by genetic factors. Compared with 11.76% of the healthy controls, 56.25% of the adolescents with early-onset schizophrenia exhibited very high levels of social mistrust on all three subscales of the SMS. The SMS exhibited good discriminant validity in distinguishing adolescents with childhood-onset schizophrenia from healthy controls and showed associations with a broad range of symptoms assessed by the PANSS. CONCLUSIONS: Social mistrust assessed by the SMS may be heritable. The SMS demonstrates good discriminant validity with clinical diagnoses of schizophrenia. However, it seems to be correlated with multiple aspects of psychopathology in the schizophrenia group, rather than being specific to delusional ideation/paranoia.