Gray matter correlates of impulsivity in psychopathy and in the general population differ by kind, not by degree: a comparison of systematic reviews

Psychiatric comorbid disorders and impulsivity in patients with drug-resistant temporal and extra-temporal focal epilepsies

PURPOSE

To analyze patients with drug-resistant focal epilepsy from temporal (TLE) and extra-temporal origin (ETE) and to compare the prevalence of psychiatric comorbid disorders and impulsivity between them and a control group.

METHODS

Consecutively studied patients with TLE and ETE confirmed with Video-EEG were included. Standardized psychiatric assessment was conducted using the Structured Clinical Interview for Axis I and II diagnosis of DSM-IV (SCID I-II), the Barrat-11 scale for impulsivity, and Beck inventory for depression. Parametric and nonparametric tests were performed.

RESULTS

Seventy-three patients with temporal lobe epilepsy (TLE), 21 extra-temporal epilepsy (ETE) and 58 healthy control subjects were included. Both groups of patients showed a high frequency of Axis I comorbid psychiatric disorders: Depression was the most frequent disorder followed by Anxiety Disorders. Furthermore, Axis II (Personality disorders) were also diagnosed, similarly in both groups of patients (p > 0.05). In addition, both TLE and ETE groups presented higher impulsivity scores compared with the control group (p < 0.01). ETE showed a tendency to a higher impulsivity in the motor factor (p = 0.05). Among patients with TLE, a left laterality of the epileptogenic zone, and the presence of comorbid psychiatric disorders (depression), were found as independent factors associated with higher impulsivity (p < 0.05).

CONCLUSION

Comorbid depression associated with higher impulsivity are important issues to consider in behavioral and clinical evaluation of patients with drug-resistant focal epilepsies, with the aim to set up a prompt treatment.

Dietary Intakes of Long-Chain Polyunsaturated Fatty Acids and Impulsivity: Comparing Non-Restricted, Vegetarian, and Vegan Diets

BACKGROUND

Research suggests a link between deficiencies in omega-3 long-chain polyunsaturated fatty acids (LCPUFAs) and impulsivity among psychiatric populations. However, this association is less evident in non-clinical populations. As omega-3 LCPUFAs are predominantly sourced through fish consumption, non-fish dieters may be more vulnerable to higher impulsivity.

METHODS

This cross-sectional observational study explored the association between lower intakes of omega-3 LCPUFA food sources and higher self-reported measures of impulsivity among healthy adults consuming non-restricted, vegetarian, and vegan diets.

RESULTS

The results from the validated Food Frequency Questionnaire showed significantly lower estimated omega-3 LCPUFA intakes among vegans and vegetarians when compared with people consuming non-restricted diets. Furthermore, although all groups scored within the normal range of impulsivity measures, vegans scored comparatively higher. Vegans also scored significantly higher in impulsivity control relating to attention than those consuming non-restricted diets.

CONCLUSIONS

The significantly lower omega-3 LCPUFA dietary intakes in the vegan diets were associated with higher scores in the second-order attentional aspect of self-reported impulsiveness.

A neurocognitive model of early onset persistent and desistant antisocial behavior in early adulthood

It remains unclear which functional and neurobiological mechanisms are associated with persistent and desistant antisocial behavior in early adulthood. We reviewed the empirical literature and propose a neurocognitive social information processing model for early onset persistent and desistant antisocial behavior in early adulthood, focusing on how young adults evaluate, act upon, monitor, and learn about their goals and self traits. Based on the reviewed literature, we propose that persistent antisocial behavior is characterized by domain-general impairments in self-relevant and goal-related information processing, regulation, and learning, which is accompanied by altered activity in fronto-limbic brain areas. We propose that desistant antisocial development is associated with more effortful information processing, regulation and learning, that possibly balances self-relevant goals and specific situational characteristics. The proposed framework advances insights by considering individual differences such as psychopathic personality traits, and specific emotional characteristics (e.g., valence of social cues), to further illuminate functional and neural mechanisms underlying heterogenous developmental pathways. Finally, we address important open questions and offer suggestions for future research to improve scientific knowledge on general and context-specific expression and development of antisocial behavior in early adulthood.

Value-based decision-making network functional connectivity correlates with substance use and delay discounting behaviour among young adults

Substance use disorders are characterized by reduced control over the quantity and frequency of psychoactive substance use and impairments in social and occupational functioning. They are associated with poor treatment compliance and high rates of relapse. Identification of neural susceptibility biomarkers that index risk for developing a substance use disorder can facilitate earlier identification and treatment. Here, we aimed to identify the neurobiological correlates of substance use frequency and severity amongst a sample of 1,200 (652 females) participants aged 22-37 years from the Human Connectome Project. Substance use behaviour across eight classes (alcohol, tobacco, marijuana, sedatives, hallucinogens, cocaine, stimulants, opiates) was measured using the Semi-Structured Assessment for the Genetics of Alcoholism. We explored the latent organization of substance use behaviour using a combination of exploratory structural equation modelling, latent class analysis, and factor mixture modelling to reveal a unidimensional continuum of substance use behaviour. Participants could be rank ordered along a unitary severity spectrum encompassing frequency of use of all eight substance classes, with factor score estimates generated to represent each participant's substance use severity. Factor score estimates and delay discounting scores were compared with functional connectivity in 650 participants with imaging data using the Network-based Statistic. This neuroimaging cohort excludes participants aged 31 and over. We identified brain regions and connections correlated with impulsive decision-making and poly-substance use, with the medial orbitofrontal, lateral prefrontal and posterior parietal cortices emerging as key hubs. Functional connectivity of these networks could serve as susceptibility biomarkers for substance use disorders, informing earlier identification and treatment.

Psychopathy and response inhibition: A meta-analysis of go/no-go and stop signal task performance

Traditional and more modern conceptualizations of psychopathy cite problems with impulse control. However, the extent to which these problems represent a cardinal feature of the disorder has been debated. In this study, we conducted a preregistered systematic review and meta-analysis, searching Embase, Medline, PsycINFO, and PubMed, for studies from inception to January 6th, 2022. We included 21 studies, published between 2009 and 2021, that reported on the relationship of psychopathy with performance on the go/no-go or stop signal task. A multilevel random-effects meta-analysis, including 43 effect sizes from 17 studies (total N = 1394), showed a significant pooled association between psychopathy and response inhibition r = -0.143 (95 % CI: -0.250 to -0.034). The relatively small effect size, although statistically significant, calls in to question the extent to which difficulties in response inhibition should be considered a cardinal feature of psychopathic personality. The strength of the relationship did not significantly differ between non-criminal and criminal samples, gender, task type, tasks with or without an affective component, or by psychopathy trait dimension.

Suicidal behavior in Mexican adolescents: A test of a latent class model using two independent probability samples

Suicidal behavior is a serious health issue that affects the adolescent population and that may be prevented through evidence-based approaches. There are many risk factors involved in suicidal behavior, but there are few studies encompassing the complex relationships between them. This study tested the similarity between two latent class models from two different epidemiological samples of middle-school students and evaluated if the multinomial regression model replicated the associations between the classes and the psychosocial variables. Data of 4013 adolescents from the Mexican states of Campeche and Querétaro were included in LCA to characterize suicide behavior and associated factors. The most likely latent class membership was used as the outcome in multinomial regression models. The model with data from Querétaro was consistent with the previous LC model from Campeche. The four latent classes were nearly identical for both populations and can be defined as follows: 1) "No Problems," included 73% of the adolescents; 2) "Drug Use Only," comprised 7% of the adolescents; 3) "Suicidal Behavior, No Depression," captured 8% of the adolescents (25% reported binge drinking in the past month, 50% self-inflicted injuries, and 43% low-lethality suicide attempt); 4) "Depression and Suicidal Behavior," comprised 12% of the sample (66% met criteria for Major Depressive Episode, 28% reported binge drinking in the past month, and 11% had a high-lethality suicide attempt). The congruence between the models and the consistency with identified factors highlight the need for appropriate and effective prevention strategies to minimize risk factors and reinforce protective factors in the adolescent population.

A Multidimensional Examination of Psychopathy Traits and Gray Matter Volume in Adults

Uncovering the neurobiological abnormalities that may contribute to the manifestation of psychopathic traits is an important step toward understanding the etiology of this disorder. Although many studies have examined gray matter volume (GMV) in relation to psychopathy, few have examined how dimensions of psychopathic traits interactively relate to GMV, an approach that holds promise for parsing heterogeneity in neurobiological risk factors for this disorder. The aim of this study was to investigate the affective-interpersonal (Factor 1) and impulsive-antisocial (Factor 2) dimensions of psychopathy in relation to cortical surface and subcortical GMV in a mixed-gender, high-risk community sample with significant justice-system involvement (N = 156, 50.0% men). Cortex-wide analysis indicated that (i) the Factor 1 traits correlated negatively with GMV in two cortical clusters, one in the right rostral middle frontal region and one in the occipital lobe, and (ii) the interaction of the affective-interpersonal and impulsive-antisocial traits was negatively associated with GMV bilaterally in the parietal lobe, such that individuals high on both trait dimensions evidenced reduced GMV relative to individuals high on only one psychopathy factor. An interactive effect also emerged for bilateral amygdalar and hippocampal GMV, such that Factor 1 psychopathic traits were significantly negatively associated with GMV only at high (but not low) levels of Factor 2 traits. Results extend prior research by demonstrating the neurobiological correlates of psychopathy differ based on the presentation of Factor 1 and 2 traits.

Brain gray matter structures associated with trait impulsivity: A systematic review and voxel-based meta-analysis

Trait impulsivity is a multifaceted personality characteristic that contributes to maladaptive life outcomes. Although a growing body of neuroimaging studies have investigated the structural correlates of trait impulsivity, the findings remain highly inconsistent and heterogeneous. Herein, we performed a systematic review to depict an integrated delineation of gray matter (GM) substrates of trait impulsivity and a meta-analysis to examine concurrence across previous whole-brain voxel-based morphometry studies. The systematic review summarized the diverse findings in GM morphometry in the past literature, and the quantitative meta-analysis revealed impulsivity-related volumetric GM alterations in prefrontal, temporal, and parietal cortices. In addition, we identified the modulatory effects of age and gender in impulsivity-GM volume associations. The present study advances understanding of brain GM morphometry features underlying trait impulsivity. The findings may have practical implications in the clinical diagnosis of and intervention for impulsivity-related disorders.