Effort-cost decision-making associated with negative symptoms in schizophrenia and bipolar disorder.

Motivational deficits and reduced goal-directed behavior for external rewards have long been considered an important features of negative symptoms in patients with schizophrenia (SCZ). Negative symptoms have also a high prevalence in bipolar disorder (BP). We used a transdiagnostic approach in order to examine association between negative symptoms and effort allocation for monetary rewards. 41 patients with SCZ and 34 patients with BP were enrolled in the study along with 41 healthy controls (HC). Effort-Expenditure for Rewards Task (EEfRT) was used to measure subjects' effort allocation for monetary rewards. Generalized estimating equation models were used to analyze EEfRT choice behavior. Negative symptoms were assessed using the Brief Negative Symptom Scale (BNSS). SCZ and BP groups expended lower effort to obtain a monetary rewards compared to HC. Severity of negative symptoms was negatively correlated with EEfRT performance in both diagnostic groups. Each diagnostic group showed lower effort allocation for monetary rewards compared to HC suggesting reduced motivation for monetary rewards. In addition, our results suggest that abnormal effort-based decision-making might be a transdiagnostic factor underlying negative symptoms.

Social Cognition in Opioid Use Disorder.

Background: Opioid use disorder (OUD) is associated with significant functional impairment and neurocognitive dysfunction, but only a handful of studies have investigated social cognitive abilities in this condition. This study aimed to investigate facial emotion recognition accuracy/biases and two different aspects of theory of mind (ToM) (ToM-decoding vs ToM-reasoning) in people with recovered OUD. Methods: The participants included 32 people with recovered OUD who were on Buprenorphine + Naloxone (B/N) maintenance treatment and 32 healthy controls. In addition to neurocognitive tasks, both groups were assessed by a facial emotion recognition task, the faux pas recognition task, and the reading the mind from the eyes task. Results: In comparison to healthy controls, people on B/N maintenance treatment showed deficits in facial emotion recognition (d = 1.32) and both aspects of ToM (d = 0.87-1.21). In analyses of individual emotions, people on B/N maintenance treatment had decreased accuracy in recognition of anger and fear and had a bias to identify other emotions as sad. The duration of opioid use was robustly associated with difficulties in the recognition of anger. Conclusion: People in B/N maintenance treatment have significant difficulties in recognizing the emotions and mental states of others. Deficits in social cognition might be important for understanding the difficulties in interpersonal and social functioning in people with OUD.

Reduced sensitivity but intact motivation to monetary rewards and reversal learning in obesity.

BACKGROUND: Obesity has been linked to altered reward processing but little is known about which components of reward processing including motivation, sensitivity and learning are impaired in obesity. We examined whether obesity compared to healthy weight controls is associated with differences in distinct subdomains of reward processing. To this end, we used two established paradigms, namely the Effort Expenditure for Rewards task (EEfRT) and the Probabilistic Reversal Learning Task (PRLT). METHODS: 30 individuals with obesity (OBS) and 30 healthy weight control subjects (HC) were included in the study. Generalized estimating equation models were used to analyze EEfRT choice behavior. PRLT data was analyzed using both conventional behavioral variables of choices and computational models. RESULTS: Our findings from the different tasks speak in favor of a hyposensitivity to non-food rewards in obesity. OBS did not make fewer overall hard task selections compared to HC in the EEfRT suggesting generally intact non-food reward motivation. However, in highly rewarding trials (i.e.,trials with high reward magnitude and high reward probability),OBSmadefewer hard task selections compared to normal weight subjects suggesting decreased sensitivity to highly rewarding non-food reinforcers. Hyposensitivity to non-food rewards was also evident in OBS in the PRLT as evidenced by lower win-stay probability compared to HC. Our computational modelling analyses revealed decreased stochasticity but intact reward and punishment learning rates in OBS. CONCLUSIONS: Our findings provide evidence for intact reward motivation and learning in OBS but lower reward sensitivity which is linked to stochasticity of choices in a non-food context. These findings might provide further insight into the mechanism underlying dysfunctional choices in obesity.

Quality of Life of Individuals with Bipolar Disorder and Schizophrenia.

Introduction: Quality of life (QoL) is a concept defined as a subjective perception of one's position in life and is negatively affected in many psychiatric illnesses such as bipolar disorder (BD) and schizophrenia (SCZ). It is hypothesized that therapeutic approaches based on QoL can increase the patient's adherence to treatment and contribute to a satisfactory life. This study aimed to compare the QoL of individuals having BD and schizophrenia with that of healthy controls (HCs) and to investigate the impact of the state of remission on QoL. Method: The World Health Organization QoL Scale-Short Form (WHOQOL-Bref) was administered to individuals with BD (n=124) and SCZ (n=74) and to HCs (n=81) to evaluate QoL. The WHOQOL-Bref subscale and total scores were compared between the groups using multifactor analysis of covariance (MANCOVA) by considering age and education level as the covariates. Then, the patient groups were compared using MANCOVA based on the state of remission by taking age, level of education, and Global Assessment of Functioning scores as the covariates. The relationship between clinical features and QoL scores was evaluated using correlation analysis, and linear regression analysis was applied for the variables that were found to be significant. Results: It was found that individuals with SCZ or BD had lower WHOQOL-Bref psychological, social, and total scores than HCs. Those with SCZ additionally had lower physical and environmental subscale scores than HCs. Furthermore, those with SCZ had lower WHOQOL-Bref physical, psychological, social, and total scores than individuals with BD. There was no significant difference in WHOQOL-Bref scores between individuals with BD and SCZ in the remission period. WHOQOL-Bref physical, psychological, and total scores were found to be significantly lower in unremitted BD patients when compared with remitted BD patients. Unremitted BD patients were found to have significantly lower WHOQOL-Bref psychological, environmental, and total scale scores than unremitted SCZ patients. Conclusion: It can be concluded that the QoL of individuals with BD is between that of healthy individuals and those with SCZ. However, unremitted BD patients have lower QoL than unremitted SCZ patients. Both patient groups display similar features during remission. Identifying the similarities and differences in terms of QoL in both patient groups is of great importance to develop the best type of treatment for the patients.

Computational analysis of probabilistic reversal learning deficits in male subjects with alcohol use disorder.

Background: Alcohol use disorder is characterized by perseverative alcohol use despite negative consequences. This hallmark feature of addiction potentially relates to impairments in behavioral flexibility, which can be measured by probabilistic reversal learning (PRL) paradigms. We here aimed to examine the cognitive mechanisms underlying impaired PRL task performance in patients with alcohol use disorder (AUDP) using computational models of reinforcement learning. Methods: Twenty-eight early abstinent AUDP and 27 healthy controls (HC) performed an extensive PRL paradigm. We compared conventional behavioral variables of choices (perseveration; correct responses) between groups. Moreover, we fitted Bayesian computational models to the task data to compare differences in latent cognitive variables including reward and punishment learning and choice consistency between groups. Results: AUDP and HC did not significantly differ with regard to direct perseveration rates after reversals. However, AUDP made overall less correct responses and specifically showed decreased win-stay behavior compared to HC. Interestingly, AUDP showed premature switching after no or little negative feedback but elevated proneness to stay when accumulation of negative feedback would make switching a more optimal option. Computational modeling revealed that AUDP compared to HC showed enhanced learning from punishment, a tendency to learn less from positive feedback and lower choice consistency. Conclusion: Our data do not support the assumption that AUDP are characterized by increased perseveration behavior. Instead our findings provide evidence that enhanced negative reinforcement and decreased non-drug-related reward learning as well as diminished choice consistency underlie dysfunctional choice behavior in AUDP.

Neurocognitive Functions in Bipolar Disorder in Relation to Comorbid ADHD.

INTRODUCTION: Bipolar disorder (BD) and attention deficit hyperactivity disorder (ADHD) often co-occur in adult population. Both conditions present various neurocognitive and behavioral problems. We aimed to examine neurocognitive functions in adult patients with comorbid BD and ADHD (BD+ADHD) in comparison to patients with only BD, only ADHD and healthy controls (HCs). METHOD: An extensive cognitive battery which evaluates verbal learning and memory, visual memory, processing speed, attention, executive functions, working memory and verbal fluency, was used to assess neurocognitive functions respectively in adult (age 18-65 years) patients with BD (n=37), ADHD (n=43), BD+ADHD (n=20) in comparison to HCs (n=51). The Multivariate Analysis of Covariance models, where age, level of education and total BIS-11 scores were included as covariates, were used for comparing neurocognitive scores among groups. RESULTS: Both BD and BD+ADHD groups showed significantly poorer performance than HCs in processing speed, attention, executive functions, and verbal fluency domains. The BD group had additional significant deficits in executive functions, verbal learning and memory domains. There were no significant differences between BD and BD+ADHD groups with regards to verbal learning and memory, visual memory, processing speed, attention, executive functions, working memory and verbal fluency domains. Patients with only ADHD showed significantly poorer performance than HCs in verbal fluency domain. CONCLUSIONS: Our results show similarities in the neurocognitive functions of adults with BD and BD+ADHD across a wide range of cognitive domains. The findings point to the need for further exploration of diverging and converging neurodevelopmental trajectories of BD and ADHD.

Rich club and reward network connectivity as endophenotypes for alcohol dependence: a diffusion tensor imaging study.

We aimed to examine the whole-brain white matter connectivity and local topology of reward system nodes in patients with alcohol use disorder (AUD) and unaffected siblings, relative to healthy comparison individuals. Diffusion-weighted magnetic resonance imaging scans were acquired from 18 patients with AUD, 15 unaffected siblings of AUD patients and 15 healthy controls. Structural networks were examined using network-based statistic and connectomic analysis. Connectomic analysis showed a significant ordered difference in normalized rich club organization (AUD < Siblings < Controls). We also found rank ordered differences (Control > Sibling > AUD) for both nodal clustering coefficient and nodal local efficiency in reward system nodes, particularly left caudate, right putamen and left hippocampus. Network-based statistic analyses showed that AUD group had significantly weaker connectivity than controls in the right hemisphere, mostly in the edges connecting putamen and hippocampus with other brain regions. Our results suggest that reward system network abnormalities, especially in subcortical structures, and impairments in rich-club organization might be related to the familial predisposition for AUD.

Abnormal white matter integrity in synthetic cannabinoid users.

Synthetic cannabinoids have become increasingly popular in the last few years especially among adolescents and young adults. However, no previous studies have assessed the effects of synthetic cannabinoids on the structure of the human brain. Understanding the harms of synthetic cannabinoid use on brain structure is therefore crucial given its increasing use. Diffusion tensor imaging (DTI) was performed in 22 patients who used synthetic cannabinoids more than five times a week for at least 1 year and 18 healthy controls. Fractional anisotropy (FA) was significantly reduced in the cannabinoid group compared to controls in a cluster of white matter voxels spanning the left temporal lobe, subcortical structures and brainstem. This cluster was predominantly traversed by the inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, fornix, cingulum-hippocampus and corticospinal tracts. Long-term use of synthetic cannabinoids is associated with white matter abnormalities in adolescents and young adults. Disturbed brain connectivity in synthetic cannabinoid users may underlie cognitive impairment and vulnerability to psychosis.