Emotional and cognitive dysregulation in schizophrenia and depression: understanding common and distinct behavioral and neural mechanisms

Ultra-high Field fMRI Reveals Effect of Ketamine on Vocal Processing in Common Marmosets

Auditory deficits are a well-known symptom in neuropsychiatric disorders such as schizophrenia. The noncompetitive N-methyl-d-aspartate receptor antagonist ketamine has been used to model sensory and cognitive deficits in nonhuman primates, but its whole-brain effects remain largely unknown. Here we employed ultra-high field functional magnetic resonance imaging at 9.4 T in awake male and female marmoset monkeys (Callithrix jacchus) to compare brain activations to conspecific vocalizations, scrambled vocalizations, and nonvocal sounds following the administration of a subanesthetic dose of ketamine. Our findings reveal a broad suppression of activations across auditory regions following ketamine compared with saline. Additionally, we observed differential effects depending on the type of sound, with notable changes in the mediodorsal thalamus and anterior cingulate cortex, particularly during the processing of vocalizations. These findings suggest a potential overlap between the effects of ketamine and neural disruptions observed in schizophrenia, particularly affecting vocalization processing.

Hypo- and hyper-activation in frontotemporal lobe during humor processing in patients with first episode schizophrenia

BACKGROUND

Patients with schizophrenia present difficulties in humor recognition and appreciation, but the neural mechanism of these deficits remains unclear. This study aimed to elucidate neural substrates underlying humor processing in patients with first episode schizophrenia (FES).

METHODS

This study recruited 40 patients with FES (illness duration ≤ 4 years) and 31 healthy controls matching for age, gender and education level. Participants completed a fMRI verbal humor processing paradigm comprising 96 stories, half for funny punch-line condition and the other half for unfunny condition. Participants were required to judge whether the story was funny or not. Signal detection theory (SDT) analysis was used to calculate d' and β values which represented sensitivity and inner criteria for humor signals respectively. The funny-unfunny contrast was analyzed to identify the brain regions related with humor processing. d' and β values were put into the imaging regression analysis.

RESULTS

Patients with FES showed significantly lower hit rate and sensitivity of humor signals (d'). At the neural level, patients with FES hypo-activated in ventral medial prefrontal cortex (vmPFC) and anterior cingulate cortex (ACC) while hyper-activated in middle temporal gyrus (MTG) and superior temporal gyrus (STG) compared to controls. In addition, activity in vmPFC and ACC was positively associated with d' and β values, while activity in STG was positively associated with β values in the clinical group.

CONCLUSIONS

Patients with FES exhibited decreased sensitivity to humor signals. Hypo-activation in frontal regions and hyper-activation in temporal regions were associated with the humor processing deficits.

Altered dynamic functional and effective connectivity in drug-naive children with Tourette syndrome

Tourette syndrome (TS) is a developmental neuropsychiatric disorder characterized by repetitive, stereotyped, involuntary tics, the neurological basis of which remains unclear. Although traditional resting-state MRI (rfMRI) studies have identified abnormal static functional connectivity (FC) in patients with TS, dynamic FC (dFC) remains relatively unexplored. The rfMRI data of 54 children with TS and 46 typically developing children (TDC) were analyzed using group independent component analysis to obtain independent components (ICs), and a sliding-window approach to generate dFC matrices. All dFC matrices were clustered into two reoccurring states, the state transition metrics were obtained. We conducted Granger causality and nodal topological analyses to further investigate the brain regions that may play the most important roles in driving whole-brain switching between different states. We found that children with TS spent more time in state 2 (PFDR < 0.001), a state characterized by strong connectivity between ICs, and switched more quickly between states (PFDR = 0.025) than TDC. The default mode network (DMN) may play an important role in abnormal state transitions because the FC that changed the most between the two states was between the DMN and other networks. Additionally, the DMN had increased degree centrality, efficiency and altered causal influence on other networks. Certain alterations related to executive function (r = -0.309, P < 0.05) and tic symptom ratings (r = 0.282; 0.413, P < 0.05) may represent important aspects of the pathophysiology of TS. These findings facilitate our understanding of the neural basis for the clinical presentation of TS.

Common and Distinct Functional Connectivity of the Orbitofrontal Cortex in Depression and Schizophrenia

Schizophrenia and depression are psychiatric disorders with overlapping clinical and biological features. This study aimed to identify common and distinct neuropathological mechanisms in schizophrenia and depression patients using resting-state functional magnetic resonance imaging (fMRI). The study included 28 patients with depression (DEP), 29 patients with schizophrenia (SCH), and 30 healthy control subjects (HC). Intrinsic connectivity contrast (ICC) was used to identify functional connectivity (FC) changes at the whole-brain level, and significant ICC differences were found in the bilateral orbitofrontal cortex (OFC) across all three groups. Further seed-based FC analysis indicated that compared to the DEP and HC groups, the FC between bilateral OFC and medial prefrontal cortex (MPFC), right anterior insula, and right middle frontal gyrus were significantly lower in the SCH group. Additionally, the FC between right OFC and left thalamus was decreased in both patient groups compared to the HC group. Correlation analysis showed that the FC between OFC and MPFC was positively correlated with cognitive function in the SCH group. These findings suggest that OFC connectivity plays a critical role in the pathophysiology of schizophrenia and depression and may provide new insights into the potential neural mechanisms underlying these two disorders.

The effects of social isolation stress and discrimination on mental health

Social isolation and discrimination are growing public health concerns associated with poor physical and mental health. They are risk factors for increased morbidity and mortality and reduced quality of life. Despite their detrimental effects on health, there is a lack of knowledge regarding translation across the domains of experimental research, clinical studies, and real-life applications. Here, we review and synthesize evidence from basic research in animals and humans to clinical translation and interventions. Animal models indicate that social separation stress, particularly in early life, activates the hypothalamic-pituitary-adrenal axis and interacts with monoaminergic, glutamatergic, and GABAergic neurotransmitter systems, inducing long-lasting reductions in serotonin turnover and alterations in dopamine receptor sensitivity. These findings are of particular importance for human social isolation stress, as effects of social isolation stress on the same neurotransmitter systems have been implicated in addictive, psychotic, and affective disorders. Children may be particularly vulnerable due to lasting effects of social isolation and discrimination stress on the developing brain. The effects of social isolation and loneliness are pronounced in the context of social exclusion due to discrimination and racism, during widespread infectious disease related containment strategies such as quarantine, and in older persons due to sociodemographic changes. This highlights the importance of new strategies for social inclusion and outreach, including gender, culture, and socially sensitive telemedicine and digital interventions for mental health care.

Recognition of affective prosody in bipolar and depressive conditions: A systematic review and meta-analysis

BACKGROUND

Inconsistent results have been reported about the affective prosody recognition (APR) ability in patients with bipolar (BD) and depressive (DD) disorders. We aimed to (i) evaluate the magnitude of APR dysfunction in BD and DD patients, (ii) identify moderators for heterogeneous results, and (iii) highlight research trends in this field.

METHODS

A computerized literature search was conducted in five electronic databases from the inception to May 9th, 2022 to identify behavioural experiments that studied APR in BD or DD patients. Effect sizes were calculated using a random-effect model and recalculated after removing outliers and adjusting publication bias.

RESULTS

Twelve eligible articles totalling 16 studies were included in the meta-analysis, aggregating 612 patients and 809 healthy controls. Individual r² ranged from 0.008 to 0.355, six of which reached a medium-to-large association strength. A medium-to-large pooled effect size (Hedges g = -0.58, 95 % CI -0.75 to -0.40, p < 0.001) for overall APR impairment in BD and DD patients was obtained. The Beck Depression Inventory score and answer option number were significant moderators. Neuropsychological mechanisms, multi-modal interaction and comorbidity effects have become primary research concerns.

LIMITATIONS

Extant statistics were insufficient for disorder-specific analysis.

CONCLUSIONS

Current findings demonstrate deficits of overall APR in BD and DD patients at a medium-to-large magnitude. APR can clinically serve for early screening and prognosis, but the depression severity, task complexity and confounding variables influence patients' APR performance. Future studies should incorporate neuroimaging approaches and investigate the effects of tonal language stimuli and clinical interventions.

Static and temporal dynamic changes of intrinsic brain activity in pediatric and adults OCD

Epidemiological and clinical age differences in obsessive-compulsive disorder (OCD) have been reported in clinical symptoms and morphometry changes; however, age differences in amplitude of low-frequency fluctuation and the relationship between ALFF imaging and clinical symptoms has not been thoroughly studied in OCD. Age may be an important feature associated with distinct subtypes of OCD. To examine the effect of age on OCD, the current study enrolled 92 OCD patients (32 pediatrics and 60 adults) and matched HCs (33 pediatrics and 84 adults), undergoing resting-state functional magnetic resonance imaging. The spontaneous brain activity was measured by static and dynamic amplitude of low-frequency fluctuation (ALFF) followed by two-way ANOVA. In pediatric OCD patients versus adult patients, we observed a significantly higher ALFF in the default mode network (DMN), including posterior cingulate, precuneus and superior frontal gyrus, and extending to cuneus, lingual gyrus. Additionally, the increased ALFF and dynamic ALFF in the precentral gyrus were found in pediatric patients. In OCD patients compared with controls, we found a significantly increased ALFF in hippocampal gyrus, cerebellum network (CN), and the dALFF in middle and inferior occipital gyrus, bilateral paracentral lobule and sensorimotor network. The findings emphasized the different patterns of static and dynamic intrinsic brain activity alterations associated with pediatric and adult OCD patients. These results provide unique insights into constructing evidenced-based distinct OCD subtypes based on brain activity and point the need of specified management for pediatric and adult OCD patients in clinical setting.

Reward and loss incentives improve spatial working memory by shaping trial-by-trial posterior frontoparietal signals

Integrating motivational signals with cognition is critical for goal-directed activities. The mechanisms that link neural changes with motivated working memory continue to be understood. Here, we tested how externally cued and non-cued (internally represented) reward and loss impact spatial working memory precision and neural circuits in human subjects using fMRI. We translated the classic delayed-response spatial working memory paradigm from non-human primate studies to take advantage of a continuous numeric measure of working memory precision, and the wealth of translational neuroscience yielded by these studies. Our results demonstrated that both cued and non-cued reward and loss improved spatial working memory precision. Visual association regions of the posterior prefrontal and parietal cortices, specifically the precentral sulcus (PCS) and intraparietal sulcus (IPS), had increased BOLD signal during incentivized spatial working memory. A subset of these regions had trial-by-trial increases in BOLD signal that were associated with better working memory precision, suggesting that these regions may be critical for linking neural signals with motivated working memory. In contrast, regions straddling executive networks, including areas in the dorsolateral prefrontal cortex, anterior parietal cortex and cerebellum displayed decreased BOLD signal during incentivized working memory. While reward and loss similarly impacted working memory processes, they dissociated during feedback when money won or avoided in loss was given based on working memory performance. During feedback, the trial-by-trial amount and valence of reward/loss received was dissociated amongst regions such as the ventral striatum, habenula and periaqueductal gray. Overall, this work suggests motivated spatial working memory is supported by complex sensory processes, and that the IPS and PCS in the posterior frontoparietal cortices may be key regions for integrating motivational signals with spatial working memory precision.

Resting-state functional connectivity of salience network in schizophrenia and depression

To explore the salience network (SN) functional alterations in schizophrenia and depression, resting-state functional magnetic resonance imaging (rs-fMRI) data from 29 patients with schizophrenia (SCH), 28 patients with depression (DEP) and 30 healthy controls (HC) were obtained. The SN was derived from data-driven group independent component analysis (gICA). ANCOVA and post hoc tests were performed to discover the FC differences of SN between groups. The ANCOVA demonstrated a significant group effect in FC with right inferior and middle temporal gyrus (ITG and MTG), left caudate, and right precentral gyrus. Post-hoc analyses revealed an opposite altered FC pattern between SN and right ITG and MTG for both patient groups. The DEP group showed a reduced FC between SN and right ITG and MTG compared with HC whereas the SCH group showed an increased FC. In addition, the SCH group showed decreased FC between SN and left caudate, and enhanced FC between SN and right precentral gyrus compared to the other two groups. Our findings suggest distinct FC of SN in schizophrenia and depression, supporting that the resting-state FC pattern of SN may be a transdiagnostic difference between depression and schizophrenia and may play a critical role in the pathogenesis of these two disorders.

Effect of mGluR2 positive allosteric modulation on frontostriatal working memory activation in schizophrenia

Negative symptoms and cognitive deficits contribute strongly to disability in schizophrenia, and are resistant to existing medications. Recent drug development has targeted enhanced NMDA function by increasing mGluR2/3 signaling. However, the clinical utility of such agents remains uncertain, and markers of brain circuit function are critical for clarifying mechanisms and understanding individual differences in efficacy. We conducted a double-blind, placebo-controlled, randomized cross-over (14 day washout) pilot study evaluating adjunctive use of the mGluR2 positive allosteric modulator AZD8529 (80 mg daily for 3 days), in chronic stable patients with schizophrenia (n = 26 analyzed). We focused on 3 T fMRI response in frontostriatal regions during an n-back working memory task, testing the hypothesis that AZD8529 produces fMRI changes that correlate with improvement in negative symptoms and cognition. We found that AZD8529 did not produce significant group-average effects on symptoms or cognitive accuracy. However, AZD8529 did increase n-back fMRI activation in striatum (p < 0.0001) and anterior cingulate/paracingulate (p = 0.002). Greater drug-versus-placebo effects on caudate activation significantly correlated with greater reductions in PANSS negative symptom scores (r = -0.42, p = 0.031), and exploratory correlations suggested broader effects across multiple symptom domains and regions of interest. These findings demonstrate that fMRI responses to mGluR2 positive modulation relate to individual differences in symptom reduction, and could be pursued for future biomarker development. Negative clinical results at the group level should not lead to premature termination of investigation of this mechanism, which may benefit an important subset of individuals with schizophrenia. Imaging biomarkers may reveal therapeutic mechanisms, and help guide treatment toward specific populations.

Altered brain functional network dynamics in obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a debilitating and disabling neuropsychiatric disorder, whose neurobiological basis remains unclear. Although traditional static resting-state magnetic resonance imaging (rfMRI) studies have found aberrant functional connectivity (FC) in OCD, alterations in whole-brain FC and topological properties in the context of brain dynamics remain relatively unexplored. The rfMRI data of 29 patients with OCD and 40 healthy controls were analyzed using group independent component analysis to obtain independent components (ICs) and a sliding-window approach to generate dynamic functional connectivity (dFC) matrices. dFC patterns were clustered into three reoccurring states, and state transition metrics were obtained. Then, graph-theory methods were applied to dFC matrices to calculate the variability of network topological organization. The occurrence of a state (State 1) with the highest modularity index and lowest mean FC between networks was increased significantly in OCD, and the fractional time in brain State 1 was positively correlated with anxiety level in patients. State 1 was characterized by having positive connections within default mode (DMN) and salience networks (SAN), and negative coupling between the two networks. Additionally, ICs belonging to DMN and SAN showed lower temporal variability of nodal degree centrality and efficiency in patients, which was related to longer illness duration and higher current obsession ratings. Our results provide evidence of clinically relevant aberrant dynamic brain activity in OCD. Increased functional segregation among networks and impaired functional flexibility in connections among brain regions in DMN and SAN may play important roles in the neuropathology of OCD.

Genome-wide association study of antipsychotic-induced sinus bradycardia in Chinese schizophrenia patients

Second-generation antipsychotics (SGAs) play a critical role in current treatment of schizophrenia (SCZ). It has been observed that sinus bradycardia, rare but in certain situations life threatening adverse drug reaction, can be induced by SGAs across different schizophrenia populations. However, the roles of genetic factors in this phenomenon have not been studied yet. In the present study, a genome-wide association study of single nucleotide polymorphisms (SNPs) was performed on Chinese Han SCZ patients to identify susceptibility loci that were associated with sinus bradycardia induced by SGAs. This study applied microarray to obtain genotype profiles of 88 Han Chinese SCZ patients. Our results found that there were no SNPs had genome-wide significant association with sinus bradycardia induced by SGAs. The top GWAS hit located in gene KIAA0247, which mainly regulated by the tumor suppressor P53 and thus plays a role in carcinogenesis based on resent research and it should not be a susceptibility locus to sinus bradycardia induced by SGAs. Using gene-set functional analysis, we tested that if top 500 SNPs mapped genes were relevant to sinus bradycardia. The result of gene prioritization analysis showed CTNNA3 was strongly correlated with sinus bradycardia, hinting it was a susceptibility gene of this ADR. Our study provides a preliminary study of genetic variants associated with sinus bradycardia induced by SGAs in Han Chinese SCZ patients. The discovery of a possible susceptibility gene shed light on further study of this adverse drug reaction in Han Chinese SCZ patients.

Altered Functional Connectivity of the Nucleus Accumbens Network Between Deficit and Non-deficit Schizophrenia

Deficit schizophrenia (DS), which is marked by stable negative symptoms, is regarded as a homogeneous subgroup of schizophrenia. While DS patients have structurally altered nucleus accumbens (NAcc) compared to non-deficit schizophrenia (NDS) patients and healthy individuals, the investigation of NAcc functional connectivity (FC) with negative symptoms and neurocognition could provide insights into the pathophysiology of schizophrenia. 58 DS, 93 NDS, and 113 healthy controls (HCs) underwent resting-state functional magnetic resonance (rsfMRI). The right and left NAcc were respectively used as seed points to construct the functional NAcc network in whole-brain FC analysis. ANCOVA compared the differences in NAcc network FC and partial correlation analysis explored the relationships between altered FC of NAcc, negative symptoms and neurocognition. Compared to HCs, both DS and NDS patients showed decreased FC between the left NAcc (LNAcc) and bilateral middle cingulate gyrus, and between the right NAcc (RNAcc) and right middle frontal gyrus (RMFG), as well as increased FC between bilateral NAcc and bilateral lingual gyrus. Moreover, the FC between the LNAcc and bilateral calcarine gyrus (CAL) was lower in the DS group compared to NDS patients. Correlation analysis indicated that FC value of LNAcc-CAL was negatively correlated to negative symptoms. Furthermore, aberrant FC values within the NAcc network were correlated with severity of clinical symptoms and neurocognitive impairments in DS and NDS patients. This study demonstrated abnormal patterns of FC in the NAcc network between DS and NDS. The presence of altered LNAcc-CAL FC might be involved in the pathogenesis of negative symptoms in schizophrenia.

Rethinking Schizophrenia and Depression Comorbidity as One Psychiatric Disorder Entity: Evidence From Mouse Model

Schizophrenia is frequently accompanied by depressive symptoms, but the pathological mechanisms remain to be elucidated. In this study, we used chronic unpredicted mild stress plus MK801 injection to generate a mouse model of schizophrenia with depression, in which in vivo 2-photon calcium imaging and electrophysiological recordings were performed in conjunction with behavioral phenotyping. Compared to mice models with classical depression or to schizophrenia models, the animal models with schizophrenia and depression comorbidity presented worse psychotic and depressive symptoms. These behavioral deficits are associated with impaired neuronal calcium activities in the frontal cortex and thalamic nuclei. Moreover, in sharp contrast to classical models that have a satisfactory response to antipsychotic or antidepressant drugs, this novel schizophrenia with depression model is resilient to combined drug treatment in terms of behavioral and functional recovery. Taken together, these data indicate that schizophrenia with depression likely involves a unique pathophysiology that is different from schizophrenia or depression alone.

Altered resting-state dynamic functional brain networks in major depressive disorder: Findings from the REST-meta-MDD consortium

BACKGROUND

Major depressive disorder (MDD) is known to be characterized by altered brain functional connectivity (FC) patterns. However, whether and how the features of dynamic FC would change in patients with MDD are unclear. In this study, we aimed to characterize dynamic FC in MDD using a large multi-site sample and a novel dynamic network-based approach.

METHODS

Resting-state functional magnetic resonance imaging (fMRI) data were acquired from a total of 460 MDD patients and 473 healthy controls, as a part of the REST-meta-MDD consortium. Resting-state dynamic functional brain networks were constructed for each subject by a sliding-window approach. Multiple spatio-temporal features of dynamic brain networks, including temporal variability, temporal clustering and temporal efficiency, were then compared between patients and healthy subjects at both global and local levels.

RESULTS

The group of MDD patients showed significantly higher temporal variability, lower temporal correlation coefficient (indicating decreased temporal clustering) and shorter characteristic temporal path length (indicating increased temporal efficiency) compared with healthy controls (corrected p < 3.14×10-3). Corresponding local changes in MDD were mainly found in the default-mode, sensorimotor and subcortical areas. Measures of temporal variability and characteristic temporal path length were significantly correlated with depression severity in patients (corrected p < 0.05). Moreover, the observed between-group differences were robustly present in both first-episode, drug-naïve (FEDN) and non-FEDN patients.

CONCLUSIONS

Our findings suggest that excessive temporal variations of brain FC, reflecting abnormal communications between large-scale bran networks over time, may underlie the neuropathology of MDD.

Effects of depression and cognitive impairment on quality of life in older adults with schizophrenia spectrum disorder: Results from a multicenter study

BACKGROUND

Little is known about the respective effects of depression and cognitive impairment on quality of life among older adults with schizophrenia spectrum disorder.

METHODS

We used data from the Cohort of individuals with Schizophrenia Aged 55-years or more (CSA) study, a large multicenter sample of older adults with schizophrenia or schizoaffective disorder (N = 353). Quality of life (QoL), depression and cognitive impairment were assessed using the Quality of Life Scale (QLS), the Center of Epidemiologic Studies Depression scale and the Mini-Mental State Examination, respectively. We used structural equation modeling to examine the shared and specific effects of depression and cognitive impairment on QoL, while adjusting for sociodemographic characteristics, general medical conditions, psychotropic medications and the duration of the disorder.

RESULTS

Depression and cognitive impairment were positively associated (r = 0.24, p < 0.01) and both independently and negatively impacted on QoL (standardized β = -0.41 and β = -0.32, both p < 0.01) and on each QLS quality-of-life domains, except for depression on instrumental role and cognitive impairment on interpersonal relations in the sensitivity analyses excluding respondents with any missing data. Effects of depression and cognitive impairment on QoL were not due to specific depressive symptoms or specific cognitive domains, but rather mediated through two broad dimensions representing the shared effects across all depressive symptoms and all cognitive deficits, respectively.

LIMITATIONS

Because of the cross-sectional design of this study, measures of association do not imply causal associations.

CONCLUSIONS

Mechanisms underlying these two broad dimensions should be considered as important potential targets to improve quality of life of this vulnerable population.

The role of hedonics in the Human Affectome

Experiencing pleasure and displeasure is a fundamental part of life. Hedonics guide behavior, affect decision-making, induce learning, and much more. As the positive and negative valence of feelings, hedonics are core processes that accompany emotion, motivation, and bodily states. Here, the affective neuroscience of pleasure and displeasure that has largely focused on the investigation of reward and pain processing, is reviewed. We describe the neurobiological systems of hedonics and factors that modulate hedonic experiences (e.g., cognition, learning, sensory input). Further, we review maladaptive and adaptive pleasure and displeasure functions in mental disorders and well-being, as well as the experience of aesthetics. As a centerpiece of the Human Affectome Project, language used to express pleasure and displeasure was also analyzed, and showed that most of these analyzed words overlap with expressions of emotions, actions, and bodily states. Our review shows that hedonics are typically investigated as processes that accompany other functions, but the mechanisms of hedonics (as core processes) have not been fully elucidated.

Contrasting contributions of anhedonia to obsessive-compulsive, hoarding, and post-traumatic stress disorders

Anhedonia is a transdiagnostic construct that can occur independent of other symptoms of depression; its role in neuropsychiatric disorders that are not primarily affective, such as obsessive compulsive disorder (OCD), hoarding disorder (HD), and post-traumatic stress disorder (PTSD) has received limited attention. This paper addresses this gap. First, the data revealed a positive contribution of anhedonia, beyond the effects of general depression, to symptom severity in OCD but not in HD or PTSD. Second, anhedonia was operationalized as a reduced sensitivity to rewards, which allowed employing the value based decision making framework to investigate effects of anhedonia on reward-related behavioral outcomes, such as increased risk aversion and increased difficulty of making value-based choices. Both self-report and behavior-based measures were used to characterize individual risk aversion: risk perception and risk-taking propensities (measured using the Domain Specific Risk Taking scale) and risk attitudes evaluated using a gambling task. Data revealed the positive theoretically predicted correlation between anhedonia and risk perception in OCD; effects on self-reported risk taking and behavior-based risk aversion were non-significant. The same relations were weaker in HD and absent in PTSD. Response time during a gambling task, an index of difficulty of making value-based choices, significantly correlated with anhedonia in individuals with OCD and individuals with HD, even after controlling for general depression, but not in individuals with PTSD. The results suggest a unique contribution of one aspect of anhedonia in obsessive-compulsive disorder and confirm the importance of investigating the role of anhedonia transdiagnostically beyond affective and psychotic disorders.

Dopamine dysregulation hypothesis: the common basis for motivational anhedonia in major depressive disorder and schizophrenia?

Abnormalities in reward processing are crucial symptoms of major depressive disorder (MDD) and schizophrenia (SCH). Recent neuroscientific findings regarding MDD have led to conclusions about two different symptoms related to reward processing: motivational and consummatory anhedonia, corresponding, respectively, to impaired motivation to obtain rewards ('wanting'), and diminished satisfaction from consuming them ('liking'). One can ask: which of these is common for MDD and SCH. In our review of the latest neuroscientific studies, we show that MDD and SCH do not share consummatory anhedonia, as SCH patients usually have unaltered liking. Therefore, we investigated whether motivational anhedonia is the common symptom across MDD and SCH. With regard to the similarities and differences between the neural mechanisms of MDD and SCH, here we expand the current knowledge of motivation deficits and present the common underlying mechanism of motivational anhedonia - the dopamine dysregulation hypothesis - stating that any prolonged dysregulation in tonic dopamine signaling that exceeds the given equilibrium can lead to striatal dysfunction and motivational anhedonia. The implications for further research and treatment of MDD and SCH are also discussed.

Correlation of cognitive functions with emotional dysregulation in alcohol dependence: A preliminary study

CONTEXT AND AIMS

Dysfunction of cognition and emotion is known in alcohol dependence; however, their relationship in alcohol dependence is unknown. Thus, this study aimed to know the level of emotional dysregulation and cognitive functions and their correlation in patients with alcohol dependence.

MATERIALS AND METHODS

In this hospital-based cross-sectional study, 120 patients with alcohol dependence were consecutively recruited and assessed with sociodemographic and clinical pro forma, Montreal Cognitive Assessment (MoCA), and Difficulty in Emotional Regulation Scale-Short Form (DERS-SF).

STATISTICAL ANALYSIS

Descriptive statistical, Kruskal-Wallis H, and regression analysis.

RESULTS

Results revealed a mild level of cognitive impairment (mean MoCA score = 0 23.76) and high levels of emotional dysregulation (mean DERS-SF score = 0 26.90). On linear regression analysis (R 2 = 0.266, df = 0 1, F = 0 42.782, P =0.000), the score on MoCA had statistically significant negative association with score on DERS-SF (P = 0.001).

CONCLUSIONS

Cognitive impairment and emotional dysregulation are inversely related in patients with alcohol dependence. Improving the dysfunction may improve the outcome of alcohol dependence.

Does Cognitive Dysfunction in Bipolar Disorder Qualify as a Diagnostic Intermediate Phenotype?-A Perspective Paper

The present perspective paper addresses and discusses whether cognitive dysfunction in bipolar disorder qualifies as a diagnostic intermediate phenotype using the Robin and Guze criteria of diagnostic validity. The paper reviews current data within (1) delineation of the clinical intermediate phenotype, (2) associations of the intermediate phenotype with para-clinical data such as brain imaging and blood-based data, (3) associations to family history / genetics, (4) characteristics during long-term follow-up, and (5) treatment effects on cognition. In this way, the paper identifies knowledge gaps and suggests recommendations for future research within each of the five areas. Based on the current state of knowledge, we conclude that cognitive dysfunction does not qualify as a diagnostic intermediate phenotype or endophenotype for bipolar disorder, although promising new evidence points to emotion and reward processing abnormalities as possible putative endophenotypes.

Association of schizotypy with striatocortical functional connectivity and its asymmetry in healthy adults

Altered striatocortical functional connectivity has been suggested to be a trait marker of schizophrenia spectrum disorders, including schizotypal personality. In the present study, we examined the association between schizotypal personality traits and striatocortical functional connectivity in a sample of healthy adults. The German version of the Schizotypal Personality Questionnaire was obtained from N = 111 participants recruited from the general public. Resting-state functional magnetic resonance imaging scans were acquired at 3T. Six striatal seed regions in each hemisphere were defined and striatocortical resting-state functional connectivity (rsFC) as well as its lateralization indices was calculated. Regression analysis showed that schizotypy scores, especially from the positive dimension, were positively correlated with rsFC between ventral striatum and frontal cortex and negatively associated with rsFC between dorsal striatum and posterior cingulate. No significant associations were found between negative dimension schizotypy and striatocortical rsFC. We also found positive correlations between schizotypy total scores and lateralization index of right dorsal caudate and right rostral putamen. In conclusion, the present study extends previous evidence of altered striatocortical rsFC in the schizophrenia spectrum. The observed associations resemble in part the alterations observed in psychotic patients and their relatives, providing support for dimensionality from schizotypal personality to the clinical disorder. Hum Brain Mapp 39:288-299, 2018. © 2017 Wiley Periodicals, Inc.

Transdiagnostic differences in the resting-state functional connectivity of the prefrontal cortex in depression and schizophrenia

BACKGROUND

Depression and schizophrenia are two of the most serious psychiatric disorders. They share similar symptoms but the pathology-specific commonalities and differences remain unknown. This study was conducted to acquire a full picture of the functional alterations in schizophrenia and depression patients.

METHODS

The resting-state fMRI data from 20 patients with schizophrenia, 20 patients with depression and 20 healthy control subjects were collected. A data-driven approach that included local functional connectivity density (FCD) analysis combined with multivariate pattern analysis (MVPA) was used to compare the three groups.

RESULTS

Based on the results of the MVPA, the local FCD value in the orbitofrontal cortex (OFC) can differentiate depression patients from schizophrenia patients. The patients with depression had a higher local FCD value in the medial and anterior parts of the OFC than the subjects in the other two groups, which suggested altered abstract and reward reinforces processing in depression patients. Subsequent functional connectivity analysis indicated that the connection in the prefrontal cortex was significantly lower in people with schizophrenia compared to people with depression and healthy controls.

LIMITATION

The systematically different medications for schizophrenia and depression may have different effects on functional connectivity.

CONCLUSIONS

These results suggested that the resting-state functional connectivity pattern in the prefrontal cortex may be a transdiagnostic difference between depression and schizophrenia patients.

Gene expression profiling of the dorsolateral and medial orbitofrontal cortex in schizophrenia

Schizophrenia is a complex polygenic disorder of unknown etiology. Over 3,000 candidate genes associated with schizophrenia have been reported, most of which being mentioned only once. Alterations in cognitive processing - working memory, metacognition and mentalization - represent a core feature of schizophrenia, which indicates the involvement of the prefrontal cortex in the pathophysiology of this disorder. Hence we compared the gene expression in postmortem tissue from the left and right dorsolateral prefrontal cortex (DLPFC, Brodmann's area 46), and the medial part of the orbitofrontal cortex (MOFC, Brodmann's area 11/12), in six patients with schizophrenia and six control brains. Although in the past decade several studies performed transcriptome profiling in schizophrenia, this is the first study to investigate both hemispheres, providing new knowledge about possible brain asymmetry at the level of gene expression and its relation to schizophrenia. We found that in the left hemisphere, twelve genes from the DLPFC and eight genes from the MOFC were differentially expressed in patients with schizophrenia compared to controls. In the right hemisphere there was only one gene differentially expressed in the MOFC. We reproduce the involvement of previously reported genes TARDBP and HNRNPC in the pathogenesis of schizophrenia, and report seven novel genes: SART1, KAT7, C1D, NPM1, EVI2A, XGY2, and TTTY15. As the differentially expressed genes only partially overlap with previous studies that analyzed other brain regions, our findings indicate the importance of considering prefrontal cortical regions, especially those in the left hemisphere, for obtaining disease-relevant insights.

Gene expression profiling of the dorsolateral and medial orbitofrontal cortex in schizophrenia

Schizophrenia is a complex polygenic disorder of unknown etiology. Over 3,000 candidate genes associated with schizophrenia have been reported, most of which being mentioned only once. Alterations in cognitive processing - working memory, metacognition and mentalization - represent a core feature of schizophrenia, which indicates the involvement of the prefrontal cortex in the pathophysiology of this disorder. Hence we compared the gene expression in postmortem tissue from the left and right dorsolateral prefrontal cortex (DLPFC, Brodmann's area 46), and the medial part of the orbitofrontal cortex (MOFC, Brodmann's area 11/12), in six patients with schizophrenia and six control brains. Although in the past decade several studies performed transcriptome profiling in schizophrenia, this is the first study to investigate both hemispheres, providing new knowledge about possible brain asymmetry at the level of gene expression and its relation to schizophrenia. We found that in the left hemisphere, twelve genes from the DLPFC and eight genes from the MOFC were differentially expressed in patients with schizophrenia compared to controls. In the right hemisphere there was only one gene differentially expressed in the MOFC. We reproduce the involvement of previously reported genes TARDBP and HNRNPC in the pathogenesis of schizophrenia, and report seven novel genes: SART1, KAT7, C1D, NPM1, EVI2A, XGY2, and TTTY15. As the differentially expressed genes only partially overlap with previous studies that analyzed other brain regions, our findings indicate the importance of considering prefrontal cortical regions, especially those in the left hemisphere, for obtaining disease-relevant insights.