Caballero-Engel meet Lasry-Lions: A uniqueness result

In a Mean Field Game (MFG) each decision maker cares about the cross sectional distribution of the state and the dynamics of the distribution is generated by the agents' optimal decisions. We prove the uniqueness of the equilibrium in a class of MFG where the decision maker controls the state at optimally chosen times. This setup accommodates several problems featuring non-convex adjustment costs, and complements the well known drift-control case studied by Lasry-Lions. Examples of such problems are described by Caballero and Engel in several papers, which introduce the concept of the generalized hazard function of adjustment. We extend the analysis to a general "impulse control problem" by introducing the concept of the "Impulse Hamiltonian". Under the monotonicity assumption (a form of strategic substitutability), we establish the uniqueness of equilibrium. In this context, the Impulse Hamiltonian and its derivative play a similar role to the classical Hamiltonian that arises in the drift-control case.

Impact of Social Media Addiction and Internet Gaming Disorder on Sleep Quality: Serial Mediation Analyses

Poor sleep quality is a concerning and prevalent consequence of social media addiction (SMA) and internet gaming disorder (IGD). Due to the lack of research examining how SMA and IGD lead to poor sleep quality, the current study aimed to understand the relationship between SMA and sleep quality, as well as that between IGD and sleep quality, through impulse control and bedtime procrastination. The study tested the hypotheses that higher levels of SMA and IGD would predict lower levels of impulse control, which would then predict higher levels of bedtime procrastination, leading to poorer sleep quality. A serial mediation analysis was performed with a sample of 221 participants (63.3% females, 34.4% males, and 2.3% prefer not to say) aged 18 to 53 years (M = 23.64, SD = 5.72). Participants completed questionnaires that assessed for social media addiction, internet gaming disorder, impulse control factor, bedtime procrastination, and sleep quality. There was a full serial mediation of impulse control and bedtime procrastination in the relationship between SMA and sleep quality, as well as that between IGD and sleep quality, providing support for the hypotheses. The findings provide the knowledge needed to develop and implement strategies that target impulse control issues and reduce bedtime procrastination to improve sleep quality.

Rewiring the future: drugs abused in adolescence may predispose to mental illness in adult life by altering dopamine axon growth

Adolescence is a period of increased exploration and novelty-seeking, which includes new social behaviors, as well as drug experimentation, often spurred on by peer pressure. This is unfortunate, as the immature state of the adolescent brain makes it particularly susceptible to the negative developmental impact of drug use. During adolescence, dopamine terminals, which have migrated from the ventral tegmental area, pause in the nucleus accumbens, before segregating by either forming local connections or growing towards the prefrontal cortex (PFC). This developmentally late and lengthy process renders adolescent dopamine axon pathfinding vulnerable to disruption by substance use. Indeed, exposure to stimulant drugs in adolescent male mice, but not females, triggers dopamine axons to mistarget the nucleus accumbens and to grow ectopically to the PFC. Some evidence suggests that at this novel site, the functional organization of the ectopic dopamine axons mirrors that of the intended target. The structural rewiring dysregulates local synaptic connectivity, leading to poor impulse control ability, deficits of which are a core symptom of substance-use disorders. In the present commentary, we argue that different substances of abuse induce dopamine mistargeting events with the off-target trajectory prescribed by the type of drug, leading to psychiatric outcomes later in life.

Characterizing motor impulsivity of individuals classified as overweight to obese

Deficits in the impulse control system are an important predictor of energy intake and body weight. Adults classified as overweight to obese may possess these deficits as a general behavioral trait or they may be food-specific. The present study assessed motor impulsivity (ability to suppress a pre-potent response) when presented with food and neutral (non-food) cues, testing if deficits in motor impulsivity is specific to food cues or a general trait among participants classified as overweight to obese. The proportion of inhibitory failures to no-go targets following food cues (10.8%) was significantly greater than the proportion of inhibitory failures to no-go targets following neutral cues (1.9%, p ​< ​0.001). These differences remained when covering for sex and hunger. This indicates deficits in food-specific impulse control (as opposed to general impulse control) are present in those classified as overweight to obese. Understanding the specific aspect of impulse control that is present in this population is needed for the development of future impulse control training interventions that seek to change eating behaviors as a means for weight control.

Emotion regulation tendencies and cardiovascular responses to repeated acute psychological stress

Poor emotion regulation has been associated with cardiovascular disease (CVD) through maladaptive cardiovascular responses to psychological stress. However, there has been scant research examining the relationship between emotion regulation and habituation of cardiovascular responses to recurrent stress, which may be more directly applicable to the experience of stress in everyday life. The aims of the current study were to examine the associations between emotion regulation tendencies and cardiovascular stress reactivity, as well as habituation of cardiovascular reactivity across repeated stressors. A sample of 453 participants (mean (SD) age = 19.5 (1.3) years; 62 % women) completed a repeated stress paradigm, which consisted of two 10-minute baselines and two identical 4-minute stress tasks, separated by a 10-minute recovery period. Heart rate (HR) was measured continuously; systolic/diastolic blood pressures (SBP/DBP) were measured every 2 min. At the end of the visit, participants completed the Emotion Regulation Questionnaire (ERQ) and Difficulties in Emotion Regulation Scale (DERS). Results indicate that impulse control difficulties when distressed (a DERS subscale) were significantly associated with blunted SBP, DBP, and HR reactivity to both stressors, as well as impaired HR habituation across the stressors. None of the ERQ subscales (cognitive reappraisal, expressive suppression) were found to be associated with cardiovascular stress reactivity or habituation. The outcomes of this study demonstrate a potential underlying physiological pathway through which impulse control difficulties when distressed may contribute to CVD risk. This study also reveals the importance of extending traditional cardiovascular stress reactivity protocols to include multiple exposures of the same stress task.

Individual differences in the effects of salience and reward on impulse control and action selection

Impulse control and adequate decision making are vital functions when it comes to detection and adherence to personal goals and societal rules. In the current study we tested the hypothesis that increasing the salience of environmental cues would be most effective in improving impulse control, as assessed by a stop-signal task, in subjects with low environmental susceptibility as indexed by low pre-stimulus EEG alpha power. In addition, we anticipated that an external-reward manipulation improves performance during a Go/No go task, especially in individuals with low task-induced motivation as indexed by low theta/beta power ratios. High salience of stop signals enhanced stopping performance but there was no difference in responsivity to the salience manipulation between participants with high and low EEG alpha power. Individuals with low theta/beta power ratios responded more accurately when rewards were involved. Together these results suggest that increasing the salience of external cues may help impulse control in general, whereas the effectiveness of external-reward manipulations is higher in individuals with low task-induced motivation.

Using computer-based habit versus chess-based cognitive remediation training as add-on therapy to modify the imbalance between habitual behavior and cognitive control in tobacco use disorder: protocol of a randomized controlled, fMRI study

BACKGROUND

Although the vast majority of smokers are aware of the enormous preventable health hazards caused by smoking, only a small percentage of smokers manage to remain abstinent in the long term. One possible explanation for this discrepancy lies in the inflexibility of addictive behavior and associated disadvantageous decision-making. According to a dual-process theory of decision-making, two distinct decision systems can be identified. One slow deliberate system based on desirable expectations of outcome value described as goal-directed behavior and a fast reflexive system based on habitual instrumental behavior and driven by reinforcement experienced in the past. In the course of addiction development, an imbalance occurs between habitual behavior and goal-directed. The present study aims to investigate the modifiability of the balance between habitual and goal-directed behavior at the neurobiological and behavioral level in smokers using two different novel add-on therapies. We hypothesize that both interventions change the balance between goal-directed and habitual behavior, but by different mechanisms. Whereas a cognitive remediation treatment should directly improve cognitive control, in contrast an implicit priming task should affect the early processing and the emotional valence of smoking and smoking cues.

METHODS

We will conduct a randomized controlled study in treatment-seeking individuals with tobacco use disorder applying either chess-based cognitive remediation training (N = 30) or implicit computer-based habit-modifying training (N = 30) as add on therapy compared to the standard smoking cessation group therapy (N = 30) only. We will address neurobiological and neuropsychological correlates associated with craving, reward devaluation, cue reactivity and attentional bias. In addition, various effects of treatment and prediction of treatment outcome will be examined using behavioral and neural measures.

DISCUSSION

The present study will apply different examination methods such as functional magnetic resonance imaging, neuropsychological tests, and self-report before and after the interventions. This allows the identification of intervention-specific mechanisms and therefore potential neurobiology-based specific treatment targets for individuals with Tobacco Use Disorder.

TRIAL REGISTRATION

Registered at clinicaltrials.gov/ct2/show/NCT03764969 (05 December 2018).

Emotion dysregulation and mindfulness in non-suicidal self-injury

This study examined the association between mindfulness and engagement in non-suicidal self-injury (ENSSI) and whether emotion dysregulation explains this association. A secondary objective was to explore the difference between participants who engaged in a suicide attempt and those who only engaged in non-suicidal self-injury. A sample of 201 psychiatric patients (62.7% female; age range: 18-71 years old) participated in the study. The path analysis indicated that trait mindfulness was negatively associated with all emotion dysregulation dimensions and that one of these dimensions, impulse control difficulty, was associated with higher ENSSI. Moreover, impulse control difficulty was associated with increased odds of having attempted suicide. These findings suggest that mindfulness is a relevant construct to ENSSI with and without a suicide attempt. Future studies should investigate mindfulness-based interventions for ENSSI and the role played by the capacity to control impulses when experiencing negative emotions.

Increased Urination Urgency Exacerbates Sexual Risk-Taking Through Heightened Sexual Arousal

Increased urination urgency has been shown to facilitate impulse control in cognitive domains, but its effects in other areas are unknown. We examined whether inhibitory spillover effects would replicate and extend to close relationships-specifically, influencing decision making related to sexual risk-taking. Across three studies, we either measured (Studies 1 and 3) or manipulated (Study 2) participants' bladder pressure and assessed sexual self-control using a questionnaire of sexual risk-taking intentions (Study 1) or a simulated semi-behavioral sexual risk-taking (Choose Your Own Sexual Adventure) task (Studies 2 and 3). Study 1 (N = 44 men, 59 women) showed greater urination urgency was associated with greater sexual risk-taking. Study 2 (N = 65 men, 91 women) showed that increasing urination urgency led to greater sexual risk-taking, but only among men. Study 3 (N = 86 men, 183 women) showed elevated urination urgency was associated with an increase in sexual arousal, which accounted for the greater sexual risk-taking.

Inhibitory framing in hypersexual patients with Parkinson's disease. An fMRI pilot study

Hypersexuality in medicated patients with PD is caused by an increased influence of motivational drive areas and a decreased influence of inhibitory control areas due to dopaminergic medication. In this pilot study, we test a newly developed paradigm investigating the influence of dopaminergic medication on brain activation elicited by sexual pictures with and without inhibitory contextual framing. Twenty PD patients with and without hypersexuality were examined with fMRI either OFF or ON standardized dopaminergic medication. The paradigm consisted of a priming phase where either a neutral context or an inhibitory context was presented. This priming phase was either followed by a sexual or a neutral target. Sexual, compared to neutral pictures resulted in a BOLD activation of various brain regions implicated in sexual processing. Hypersexual PD patients showed increased activity compared to PD controls in these regions. There was no relevant effect of medication between the two groups. The inhibitory context elicited less activation in inhibition-related areas in hypersexual PD, but had no influence on the perception of sexual cues. The paradigm partially worked: reactivity of motivational brain areas to sexual cues was increased in hypersexual PD and inhibitory contextual framing lead to decreased activation of inhibitory control areas in PD. We could not find a medication effect and the length of the inhibitory stimulus was not optimal to suppress reactivity to sexual cues. Our data provide new insights into the mechanisms of hypersexuality and warrant a replication with a greater cohort and an optimized stimulus length in the future.

Translational relevance of forward genetic screens in animal models for the study of psychiatric disease

Psychiatric disorders represent a significant burden in our societies. Despite the convincing evidence pointing at gene and gene-environment interaction contributions, the role of genetics in the etiology of psychiatric disease is still poorly understood. Forward genetic screens in animal models have helped elucidate causal links. Here we discuss the application of mutagenesis-based forward genetic approaches in common animal model species: two invertebrates, nematodes (Caenorhabditis elegans) and fruit flies (Drosophila sp.); and two vertebrates, zebrafish (Danio rerio) and mice (Mus musculus), in relation to psychiatric disease. We also discuss the use of large scale genomic studies in human populations. Despite the advances using data from human populations, animal models coupled with next-generation sequencing strategies are still needed. Although with its own limitations, zebrafish possess characteristics that make them especially well-suited to forward genetic studies exploring the etiology of psychiatric disorders.

Understanding mechanisms underlying the relationship between antisocial personality disorder and substance-impaired driving among young adults involved with the justice system as minors

INTRODUCTION

Antisocial personality disorder is a risk factor associated with increased risk for substance-impaired driving. While past research has focused on identifying prevalence rates for the disorder among substance-impaired drivers, there is a dearth of research focused on identifying the mechanisms by which the disorder actually functions to increase risk for the behavior among young adults who were formerly adjudicated for a serious offense. There are cognitive, affective, and social mechanisms that may help to explain this relationship.

METHOD

Impulse control, hostility, and deviant peer association are examined as mechanisms that explain the relationship in each of these domains, respectively. The Pathways to Desistance data were utilized in analyses, comprising the responses of 1,354 youth who were adjudicated for a serious offense just prior to baseline measurements. Generalized structural equation modeling was used to examine the direct effects of antisocial personality disorder on substance-impaired driving risk and the hypothesized mechanism variables were then included in the model to determine which of them provided significant pathways through which the main relationship operated.

RESULTS

Results indicated that meeting criteria for a diagnosis of antisocial personality disorder was associated with increased risk of substance-impaired driving at follow-up. This relationship was attenuated to non-significance upon inclusion of the mechanism variables and reduced in magnitude by 20%. This attenuation was due almost entirely to impulse control. Practical Applications: This provides indication that intervention for substance-impaired driving offenders with antisocial personality disorder may be most effective when structured around improving impulse control for young adults who were previously involved with the juvenile/criminal justice system.

Executive function in obesity and anorexia nervosa: Opposite ends of a spectrum of disordered feeding behaviour?

Higher-order executive functions such as decision-making, cognitive flexibility and behavioural control are critical to adaptive success in all aspects of life, including the maintenance of a healthy body weight by regulating food intake. Performance on tasks designed to assess these aspects of cognition is impaired in individuals with obesity and anorexia nervosa (AN); conditions at either end of a spectrum of body weight disturbance. While the conceptualisation of obesity and AN as mirror images of each other makes some sense from a metabolic point of view, whether or not these conditions also reflect opposing states of executive function is less clear. Here, we review evidence from neurocognitive and neuroimaging studies to compare the direction and extent of executive dysfunction in subjects with obesity and AN and how these are underpinned by changes in structure and function of subregions of the prefrontal cortex (PFC). Both conditions of extreme body weight disturbance are associated with impaired decision-making and cognitive inflexibility, however, impulsive behaviour presents in opposing directions; obesity being associated with reduced behavioural control and AN being associated with elevated control over behaviour with respect to food and feeding. Accordingly, the subregions of the PFC that guide inhibitory control and valuation of action outcomes (dorsolateral prefrontal cortex and orbitofrontal cortex) show opposite patterns of activation in subjects with obesity compared to those with AN, whereas the subregions implicated in cognitive and behavioural flexibility (ventromedial prefrontal cortex and anterior cingulate cortex) show alterations in the same direction in both conditions but with differential extent of dysfunction. We synthesise these findings in the context of the utility of animal models of obesity and AN to interrogate the detail of the neurobiological contributions to cognition in patient populations and the utility of such detail to inform future treatment strategies that specifically target executive dysfunction.

Toward a Model of Personality Competencies Underlying Social and Emotional Skills: Insight From the Circumplex of Personality Metatraits

In recent years, there has been a growing interest in social and emotional skills (SES) both in the scientific literature and in social practice. The paper presents an overview of the ways of understanding what SES are and the catalogs thereof. There are some attempts in the literature to organize these catalogs within the Big Five traits that for a long time was claimed to be the most sound model of basic orthogonal dimensions of personality. However, further research on personality structure revealed that two metatraits can be found above the Big Five traits. These two metatraits form the basis of the Two Factor Model of personality, which was later developed into the Circumplex of Personality Metatraits. It turned out that in certain aspects models based on metatraits have a greater theoretical potential than those based on the Big Five traits. The paper presents a proposal for describing SES from the perspective of the Circumplex of Personality Metatraits rather than the Big Five. In this framework, we distinguish the concept of personality competences that underlie and organize many specific SES and identify the core personality competencies on the basis of the Circumplex of Personality Metatraits model.

To spindle or not to spindle: A replication study into spindling excessive beta as a transdiagnostic EEG feature associated with impulse control

BACKGROUND

Frontocentral Spindling Excessive Beta (SEB), a spindle-like beta-activity observed in the electroencephalogram (EEG), has been transdiagnostically associated with more problems with impulse control and sleep maintenance. The current study aims to replicate and elaborate on these findings.

METHODS

Participants reporting sleep problems (n = 31) or Attention-Deficit/Hyperactivity Disorder (ADHD) symptoms (n = 48) were included. Baseline ADHD-Rating Scale (ADHD-RS), Pittsburgh Sleep Quality Index (PSQI), Holland Sleep Disorder Questionnaire (HSDQ), and EEG were assessed. Analyses were confined to adults with frontocentral SEB.

RESULTS

Main effects of SEB showed more impulse control problems (d = 0.87) and false positive errors (d = 0.55) in participants with SEB. No significant associations with sleep or interactions with Sample were observed.

DISCUSSION

This study partially replicates an earlier study and demonstrates that participants exhibiting SEB report more impulse control problems, independent of diagnosis. Future studies should focus on automating SEB classification and further investigate the transdiagnostic nature of SEB.

Gaming to relieve tension or anxiety and associations with health functioning, substance use and physical violence in high school students

Gaming is popular among youth and gaming disorders have been introduced recently into psychiatric nomenclature systems. Motivations underlying gaming may include involvement to reduce negative emotional states and thus may link to psychiatric and overall health. Thus, the extent to which adolescents engage in gaming to relieve anxiety warrants additional investigation. Data from 2005 Connecticut high-school students were used to examine how adolescents who reported gaming to relieve tension or anxiety differed from those who reported gaming but not to relieve tension or anxiety on measures of demographics, academic performance, general health, extracurricular activities, dysphoria/depression symptoms, substance use, and aggressive or violent behaviors. Chi-square analyses and binomial and multinomial logistic regression models were conducted. Gaming to relieve anxiety was more prevalent in boys and Hispanic and Asian adolescents and associated with less extracurricular involvement, poorer academic performance, increased cigarette and other drug use, problematic internet use, and depression. Participants with gaming to relieve tension or anxiety were also more likely to report weapon-carrying, missing school because they felt unsafe, having been threatened with a weapon, having engaged in physical fights, and having experienced injuries from fights. As gaming to relieve anxiety was related to mental-health- and functioning-related measures, additional research is needed to examine the precise natures of these relationships and to translate the information into improved intervention strategies.

Adolescent depressed mood and difficulties with emotion regulation: Concurrent trajectories of change

INTRODUCTION

Adolescent depression is a significant mental health concern. Emotion regulation difficulties have been associated with subsequent depressive symptoms, though different facets of emotion regulation are rarely compared. This study examined the degree to which trajectories of change in different facets of emotion regulation (goal-directed behavior, impulse control, and regulation strategies) and depressive symptoms were associated across twelve months in a clinical adolescent sample.

METHODS

Participants included 110 adolescents from the US who were enrolled in a randomized trial that tested a cognitive-behavioral treatment for youth with co-occurring mental health and substance use concerns (M_age = 15.71 years; 57.3% male). Assessments were conducted at baseline, 3-, 6-, and 12-month follow-ups. Three separate bivariate latent basis growth curve analyses were conducted. Correlations between latent intercepts and latent slopes, as well as overall model fit, were examined.

RESULTS

Impulse control and goal-directed behavior were each associated with depressive symptoms at baseline. Additionally, change in impulse control over time was significantly associated with change in depressive symptoms. However, the same was not true for goal-directed behavior. Overall fit indices for models of emotion regulation strategies were below acceptable levels and thus could not be interpreted.

CONCLUSIONS

Findings from the present study indicate that adolescents' depressive symptoms appear to improve as their perceived ability to control impulses improves. These results suggest that addressing impulse control difficulties may be an important step in treating adolescent depression and co-occurring disorders.

Excitement-Seeking Gambling in Adolescents: Health Correlates and Gambling-Related Attitudes and Behaviors

Motivational characteristics such as excitement-seeking are key components of models of addiction, including problem gambling. Previous studies have established associations between excitement-seeking and problem gambling in youth. However, these studies have employed dimensional psychological assessments which are unlikely to be routinely administered. Other approaches to conceptualize excitement-seeking could be of value. In the present study, we employed a single question (What are the reasons that you gamble?) to identify adolescents who reported excitement-seeking motivation for gambling. Cross-sectional data from 2030 adolescent gamblers who participated in a Connecticut high-school survey were examined. Gambling perceptions and correlates of problem-gambling severity were examined relative to excitement-seeking and non-excitement-seeking gambling. Gambling perceptions were more permissive and at-risk/problem gambling was more frequent among adolescents with excitement-seeking gambling versus non-excitement-seeking gambling. A weaker relationship between problem-gambling severity and moderate and heavy alcohol use was observed for excitement-seeking versus non-excitement-seeking gambling. Excitement-seeking gambling is associated with more permissive gambling-related attitudes and riskier gambling behaviors and may account for some variance in adolescent risk of heavy alcohol use. A single question may provide important information for identifying adolescents who are at elevated risk of problem gambling and associated negative outcomes, although the utility of the question in specific settings warrants direct examination, especially given the observed high prevalence of excitement-seeking motivations for gambling.

A Comparison of Gambling-Related Cognitions and Behaviors in Gamblers from the United States and Spain

Few studies have compared the clinical characteristics of gambling disorder (GD) from a cross-cultural perspective. In the present study, we aimed to examine differences in gambling-related cognitions, gambling preferences, GD severity and other clinical and sociodemographic variables in individuals with GD in the United States and Spain. Two groups of participants with GD (from the United States of America (US; n = 109) and Spain (n = 243) were compared using the South Oaks gambling screen and the gambling-related cognitions scale. In Spain, the prevalence of participants who reported only non-strategic gambling preferences was higher, whereas in the US, participants tended to engage in a wider breadth of gambling activities. Moreover, Spanish participants reported higher GD severity, while participants in the US endorsed greater gambling-related cognitions. Our findings suggest that there may jurisdictional or cultural differences in terms of gambling-related cognitions, gambling preferences, and GD severity levels among individuals in the US versus Spain. These differences, which may reflect cultural regulatory or other factors, should be investigated further, and considered when developing and implementing interventions for GD.

Acute after-school screen time in children decreases impulse control and activation toward high-calorie food stimuli in brain regions related to reward and attention

The purpose of this study was to examine the effects of after-school sedentary screen time on children's brain activation in reward and cognitive control regions in response to pictures of high- and low-calorie foods. Thirty-two children participated in a randomized crossover study with counterbalanced treatment conditions. Conditions took place on separate days after school and included three hours of active or sedentary play. After each condition, neural activation was assessed using functional magnetic resonance imaging (fMRI) while participants completed a go/no-go task involving pictures of high- and low-calorie foods. General response inhibition was also measured using the Stroop task. Hunger was measured upon arrival to the testing facility and just prior to fMRI scans. Mixed effects models were used to evaluate main effects and interactions. Significant stimulus by condition interactions were found in the right superior parietal cortex, and left anterior cingulate cortex (Ps ≤ 0.05). High-calorie pictures elicited significantly more activation bilaterally in the orbitofrontal cortex compared to low-calorie pictures (Ps ≤ 0.05). Stroop task performance diminished significantly following the sedentary condition compared to the active (P ≤ 0.05). Subjective feelings of hunger were not different between conditions at any point. Sedentary screen time was associated with significantly decreased response inhibition and a reversed brain activation pattern to pictures of high- and low-calorie foods compared to active play, in areas of the brain important to the modulation of food intake. Decreased attention, and impulse control following sedentary screen time may contribute to disinhibited eating that can lead to overweight and obesity.

Prevalence and psychiatric comorbidities of intermittent explosive disorders in Metropolitan São Paulo, Brazil

PURPOSE

To estimate the prevalence of intermittent explosive disorder (IED) in comorbidity with other psychiatric disorders and to describe the temporal sequencing of disorders in the São Paulo Metropolitan Area, Brazil.

METHODS

Data from the São Paulo Megacity Mental Health Survey, a population-based study of 5037 adult individuals, were analyzed. The World Health Organization Composite International Diagnostic Interview (CID 3.0) was used to assess lifetime DSM-IV disorders, including IED, with a response rate of 81.3%.

RESULTS

The majority (76.8%) of respondents with IED meet the criteria for at least one other psychiatric disorder, with a prevalence almost twice as high as that observed in individuals without IED. The prevalence of any anxiety, mood, impulse control or substance use disorders in respondents with IED was more than two times higher compared to those without IED, with prevalence ratios ranging from 2.1 (95% CI 1.74-2.48) to 2.9 (95% CI 2.12-4.06). The diagnosis of IED occurred earlier than most of the other mental disorders, except for those with usual onset in early childhood, as Specific and Social Phobias and Attention Deficit Disorder.

CONCLUSION

Considering that IED is a highly comorbid disorder and has an earlier onset than most other mental comorbidities in the Brazilian general population, these results may be useful in guiding governmental mental health actions.

Reward-predictive cues elicit excessive reward seeking in adolescent rats

Impulsive behavior during adolescence may stem from developmental imbalances between motivational and cognitive-control systems, producing greater urges to pursue reward and weakened capacities to inhibit such actions. Here, we developed a Pavlovian-instrumental transfer (PIT) protocol to assay rats' ability to suppress cue-motivated reward seeking based on changes in reward expectancy. Traditionally, PIT studies focus on how reward-predictive cues motivate instrumental reward-seeking behavior (lever pressing). However, cues signaling imminent reward delivery also elicit countervailing focal-search responses (food-port entry). We first examined how reward expectancy (cue-reward probability) influences expression of these competing behaviors. Adult male rats increased rates of lever pressing when presented with cues signaling lower probabilities of reward but focused their activity at the food cup on trials with cues that signaled higher probabilities of reward. We then compared adolescent and adult male rats in their responsivity to cues signaling different reward probabilities. In contrast to adults, adolescent rats did not flexibly adjust patterns of responding based on the expected likelihood of reward delivery but increased their rate of lever pressing for both weak and strong cues. These findings indicate that control over cue-motivated behavior is fundamentally dysregulated during adolescence, providing a model for studying neurobiological mechanisms of adolescent impulsivity.

Relationship between whole blood omega-3 fatty acid levels and dorsal cingulate gray matter volume: Sex differences and implications for impulse control

During adolescence, the prefrontal cortex (PFC) undergoes substantial structural development, including cortical thinning, a process associated with improvements in behavioral control. The cingulate cortex is among the regions recruited in response inhibition and mounting evidence suggests cingulate function may be sensitive to availability of an essential dietary nutrient, omega-3 fatty acids (N3; i.e. EPA + DHA). Our primary aim was to investigate the relationship between a biomarker of omega-3 fatty acids -- percent of whole blood fatty acids as EPA + DHA (N3 Index) -- and cingulate morphology, in typically developing adolescent males (n = 29) and females (n = 33). Voxel-based morphometry (VBM) was used to quantify gray matter volume (GMV) in the dorsal region of the cingulate (dCC). Impulse control was assessed via caregiver report (BRIEF) and Go/No-Go task performance. We predicted that greater N3 Index in adolescents would be associated with less dCC GMV and better impulse control. Results revealed that N3 Index was inversely related to GMV in males, but not in females. Furthermore, males with less right dCC GMV exhibited better caregiver-rated impulse control. A simple mediation model revealed that, in males, N3 Index may indirectly impact impulse control through its association with right dCC GMV. Findings suggest a sex-specific link between levels of N3 and dCC structural development, with adolescent males more impacted by lower N3 levels than females. Identifying factors such as omega-3 fatty acid levels, which may modulate the neurodevelopment of response inhibition, is critical for understanding typical and atypical developmental trajectories associated with this core executive function.

Neuropsychiatric aspects of Parkinson disease psychopharmacology: Insights from circuit dynamics

Parkinson disease (PD) is a neurodegenerative disorder with a complex pathophysiology characterized by the progressive loss of dopaminergic neurons within the substantia nigra. Persons with PD experience several motoric and neuropsychiatric symptoms. Neuropsychiatric features of PD include depression, anxiety, psychosis, impulse control disorders, and apathy. In this chapter, we will utilize the National Institutes of Mental Health Research Domain Criteria (RDoC) to frame and integrate observations from two prevailing disease constructions: neurotransmitter anomalies and circuit physiology. When there is available evidence, we posit how unified translational observations may have clinical relevance and postulate importance outside of PD. Finally, we review the limited evidence available for pharmacologic management of these symptoms.

Relationships between perfectionism, self-report impulsivity measures and delay discounting

Perfectionism and impulsivity are multidimensional constructs. While different perfectionism dimensions are exclusively measured through self-reports, different impulsivity dimensions can be measured through self-report or behaviour via preferences for different rewards. This study explored differential associations between perfectionism and impulsivity based on both dimension and measurement modality (self-report/behavioural). We then examined whether adaptive or maladaptive perfectionism would be differentially associated with impulsivity. Two-hundred and six students completed two perfectionism and three impulsivity measures (two self-report; one behavioural). Two self-report impulsivity measures were associated with specific perfectionism dimensions, whereas the behavioural measure was not associated with perfectionism. Maladaptive perfectionism was associated with decreasing impulsivity, whereas adaptive perfectionism was associated with increasing impulsivity. Perfectionism related to impulsivity differently depending on how each construct was measured.