Behavioral Disinhibition Research Articles

Associations of Weekday and Weekend Sleep with Children's Reported Eating in the Absence of Hunger.

Insufficient average sleep duration has been inconsistently associated with poor diet and obesity risks in youth. Inconsistencies in findings across studies may be due to a general failure to examine associations in weekday versus weekend sleep. We hypothesized that greater variations in weekday and weekend sleep duration would be associated with more disinhibited eating behaviors, which, in turn, might be involved in the relationship between sleep and weight. We, therefore, examined, among healthy, non-treatment seeking youth, the associations of average weekly, weekend, and weekday sleep duration with eating in the absence of hunger (EAH), a disinhibited eating behavior associated with disordered eating and obesity. Sleep was assessed via actigraphy for 14 days. Participants completed a self-report measure of EAH. Adiposity was measured by dual-energy X-ray absorptiometry. Linear regressions were used to test the associations of sleep duration with EAH and the associations of sleep duration and EAH, with fat mass. Among 123 participants (8–17 years, 52.0% female, and 30.9% with overweight), there was no significant association between average weekly sleep and EAH. Further, there was no significant association among average weekly sleep duration or EAH and fat mass. However, average weekday sleep was negatively associated, and average weekend sleep was positively associated, with EAH (ps < 0.02). Weekend “catch-up” sleep (the difference between weekend and weekday sleep) was positively associated with EAH (p < 0.01). Findings indicate that shorter weekday sleep and greater weekend “catch-up” sleep are associated with EAH, which may place youth at risk for the development of excess weight gain over time.

Cue-dependent safety and fear learning in a discriminative auditory fear conditioning paradigm in the mouse.

Discrimination between sensory stimuli associated with safety and threat is crucial for behavioral decisions. Discriminative conditioning paradigms with two acoustic conditioned stimuli (one paired with shock [CS+], the other unpaired with shock [CS−]) have been widely used as an experimental model for fear learning. However, no attention has been paid to the effect of the CS− on safety in the paradigms, because the CS− served as a neutral cue or elevated the freezing level due to fear generalization although less effectively than the CS+. By using a noise and a tone as two acoustic CSs in a discriminative auditory fear conditioning (AFC) paradigm, here we demonstrate that mice learn safety for the CS− while showing fear for the CS+ with opposing emotional behaviors. We found that after learning mice exhibited a significant suppression of context-dependent freezing during the CS−, but not during the CS+, indicating learned safety without fear generalization for the CS−. In contrast, the mice showed an enhanced level of freezing during the CS+ even in a novel spatial context, indicating cued fear for the CS+. Moreover, the CS+ also induced rapid defensive behaviors, whereas the CS− disinhibited normal exploratory behaviors. On the other hand, mice showed no significant suppression of contextual fear during the CS− in a paradigm with a pair of tone CSs at different frequencies, although they clearly discriminated the two tones. These results suggest our AFC paradigm with the noise and tone CSs as a useful experimental model for cue-dependent discriminative learning of safety and threat.

A Genetic Model of Impulsivity, Vulnerability to Drug Abuse and Schizophrenia-Relevant Symptoms With Translational Potential: The Roman High- vs. Low-Avoidance Rats.

The bidirectional selective breeding of Roman high- (RHA) and low-avoidance (RLA) rats for respectively rapid vs. poor acquisition of active avoidant behavior has generated two lines/strains that differ markedly in terms of emotional reactivity, with RHA rats being less fearful than their RLA counterparts. Many other behavioral traits have been segregated along the selection procedure; thus, compared with their RLA counterparts, RHA rats behave as proactive copers in the face of aversive conditions, display a robust sensation/novelty seeking (SNS) profile, and show high impulsivity and an innate preference for natural and drug rewards. Impulsivity is a multifaceted behavioral trait and is generally defined as a tendency to express actions that are poorly conceived, premature, highly risky or inappropriate to the situation, that frequently lead to unpleasant consequences. High levels of impulsivity are associated with several neuropsychiatric conditions including attention-deficit hyperactivity disorder, obsessive-compulsive disorder, schizophrenia, and drug addiction. Herein, we review the behavioral and neurochemical differences between RHA and RLA rats and survey evidence that RHA rats represent a valid genetic model, with face, construct, and predictive validity, to investigate the neural underpinnings of behavioral disinhibition, novelty seeking, impulsivity, vulnerability to drug addiction as well as deficits in attentional processes, cognitive impairments and other schizophrenia-relevant traits.

Update on hereditary, autosomal dominant cathepsin-A-related arteriopathy with strokes and leukoencephalopathy (CARASAL).

Cathepsin-A-related arteriopathy with strokes and leukoencephalopathy (CARASAL) is an acronym that describes an ultra-rare, hereditary, cerebral small vessel disease. The aim is to summarize current knowledge and recent findings concerning phenotype, genotype, pathogenesis, diagnoses, and treatment options of CARASAL. The method used in the study is a systematic literature review. CARASAL is clinically characterized by a wide range of predominantly central nervous system abnormalities. These include migraine, stroke with central facial palsy, facial pain, non-positional vertigo, cognitive dysfunction with impaired concentration and behavioral disinhibition, REM-sleep behavioral disorder, and depression. CARASAL is caused by point mutations in CTSA encoding cathepsin-A. Cathepsin-A is a carboxypeptidase that associates with the lysosomal enzymes b-galactosidase and neuraminidase, promoting their stabilization. In addition, cathepsin-A degradates endothelin-1. CARASAL is a primary microangiopathy with severe atherosclerosis of arterioles and secondary leukoencephalopathy. So far, 19 patients have been reported. The frequency of CARASAL patients will most likely increase in the future, as CARASAL may be more frequently recognized with the increasingly available methods for genetic testing and advanced imaging techniques. The phenotypic and genotypic spectrum of CARASAL needs to be more extensively investigated and animal models for the disease need to be generated. Currently, the outcome cannot be sufficiently assessed, as too few cases have been reported.

Psychological and Cognitive Markers of Behavioral Variant Frontotemporal Dementia-A Clinical Neuropsychologist's View on Diagnostic Criteria and Beyond.

Behavioral variant frontotemporal dementia (bvFTD) is the second leading cognitive disorder caused by neurodegeneration in patients under 65 years of age. Characterized by frontal, insular, and/or temporal brain atrophy, patients present with heterogeneous constellations of behavioral and psychological symptoms among which progressive changes in social conduct, lack of empathy, apathy, disinhibited behaviors, and cognitive impairments are frequently observed. Since the histopathology of the disease is heterogeneous and identified genetic mutations only account for ~30% of cases, there are no reliable biomarkers for the diagnosis of bvFTD available in clinical routine as yet. Early detection of bvFTD thus relies on correct application of clinical diagnostic criteria. Their evaluation however, requires expertise and in-depth assessments of cognitive functions, history taking, clinical observations as well as caregiver reports on behavioral and psychological symptoms and their respective changes. With this review, we aim for a critical appraisal of common methods to access the behavioral and psychological symptoms as well as the cognitive alterations presented in the diagnostic criteria for bvFTD. We highlight both, practical difficulties as well as current controversies regarding an overlap of symptoms and particularly cognitive impairments with other neurodegenerative and primary psychiatric diseases. We then review more recent developments and evidence on cognitive, behavioral and psychological symptoms of bvFTD beyond the diagnostic criteria which may prospectively enhance the early detection and differential diagnosis in clinical routine. In particular, evidence on specific impairments in social and emotional processing, praxis abilities as well as interoceptive processing in bvFTD is summarized and potential links with behavior and classic cognitive domains are discussed. We finally outline both, future opportunities and major challenges with regard to the role of clinical neuropsychology in detecting bvFTD and related neurocognitive disorders.

Human prenatal exposure to polychlorinated biphenyls (PCBs) and risk behaviors in adolescence

Polychlorinated biphenyls (PCBs) are chemicals used in a variety of products before they were widely banned due to toxic effects in humans and wildlife. Because of continued persistence and ubiquity of these contaminants, risk of exposure to people living in industrialized countries is still high. Experimental research show that developmental exposure to PCB may alter function of brain pleasure centers and potentially influence disinhibitory behaviors, including tobacco and alcohol use. Yet, the potential effects of developmental PCB exposure on adolescent substance use have not been studied in humans. We used the Child Health and Development Studies (CHDS), a prospective birth cohort study in the Oakland and East Bay areas of California, to investigate associations between prenatal exposure to PCB congeners (66, 74, 99, 118, 138, 153, 170, 180, 187, and 203) and later disinhibitory behaviors in adolescents, specifically alcohol consumption and smoking, in a randomly selected sample (n = 554). Total prenatal PCB exposure was not associated with disinhibitory behaviors, among adolescents. However, the adjusted odds ratio (aOR) for being a current smoker, was higher in subjects within the third quartile of maternal PCB 66 exposure compared to those below the median (aOR = 1.93; 95% CI 1.05, 3.55). The aOR for drinking >2 alcoholic beverages per week, were also higher for adolescents within the third (aOR = 1.46; 95% CI 0.86, 2.47) and fourth quartile of PCB 66 exposure (aOR = 1.39; 95% CI 0.83, 2.35), but the differences did not reach statistical significance. These results suggest that this specific PCB congener may play a role inducing neurodevelopmental alterations that could potentially increase the risk of becoming a long-term user of tobacco and possibly alcohol. There were no notable differences between magnitude or direction of effect between boys and girls. Future replicate analyses with larger longitudinal samples and animal experimental studies of potential underlying mechanisms are warranted.

HPV vaccine status and sexual behavior among young sexually-active women in the US: evidence from the National Health and Nutrition Examination Survey, 2007-2014.

Concern has been expressed that human papillomavirus (HPV) vaccination programs might promote risky sexual behavior through mechanisms such as risk compensation, behavioral disinhibition, or perceived endorsement of sexual activity. This study assesses whether HPV vaccination status is associated with any differences in selected sexual behaviors among young sexually-active women in the US. Our dataset includes young, adult female respondents from questionnaire data collected in the National Center for Health Statistics' National Health and Nutrition Examination Survey from 2007 to 2014. The empirical approach implements a doubly robust estimation procedure, based on inverse probability of treatment weighting. For robustness, we implement several specifications for the propensity model and the outcomes model. We find no consistent association between HPV vaccination and condom usage or frequency of sex. Specifically, we find no evidence that HPV vaccination is associated with condom usage or with whether a person had sex more than 52 or more than 104 times per year. We find inconsistent evidence that HPV vaccination is associated with a person having sex more than 12 times per year. As in previous research, HPV vaccination does not appear to have a substantive effect on sexual behavior among young sexually-active women in the US.

Preliminary Evidence That Real World Sleep Timing and Duration are Associated With Laboratory-Assessed Alcohol Response.

Sleep timing and evening chronotype have been implicated in alcohol use problems but research has yet to study them in relation to theory-driven laboratory-based measures of alcohol use disorder risk. The current study examined (i) whether chronotype, sleep timing, and/or sleep duration are associated with alcohol response (subjective stimulation, sedation, and behavioral disinhibition) and (ii) if sex and race moderate these associations. Adult drinkers (N=144; 46 female participants) completed 2 counterbalanced beverage administration sessions (alcohol and nonalcohol) during which they rated stimulation/sedation and completed a cued go/no-go task. They reported bed and waketimes over 10days. Later sleep timing was associated with greater increases in alcohol stimulation, but among male and White participants only. Later sleep timing (among male participants) and greater eveningness (examined among White male participants only) were associated with greater overall stimulation on average in the alcohol session relative to the nonalcohol session, irrespective of alcohol consumption. More variable sleep duration was associated with greater increases in sedation. These findings offer preliminary, but novel evidence that sleep characteristics may relate to the relative stimulating and sedating effects of alcohol, thereby influencing the risk for alcohol problems.

Identifying factors associated with successful implementation and uptake of an evidence-based voluntary medical male circumcision program in Zambia: the Spear and Shield 2 Program.

Voluntary medical male circumcision has been shown to provide a 50%-70% reduction in the risk of HIV infection without contributing to behavioral disinhibition of safer sexual practices. This study examined the interim implementation and dissemination data of Spear and Shield 2, an HIV risk-reduction program in Zambia. The purpose of this interim review was to identify contextual challenges to implementation and implement midcourse corrections associated with sustainability of program delivery. Using a mixed-methods design, quantitative evaluations of organizational functioning, barriers to implementation, burnout, and organizational readiness, as well as qualitative data utilizing the Consolidated Framework for Implementation Research (CFIR), were examined to evaluate program implementation. Participants were 184 health care providers from 46 clinics in Zambia. Successful implementation was associated with better community and leader support, and employee readiness and motivation. Quantitative assessments were not related to implementation and provided a limited picture of implementation outcomes. Results suggest that the qualitative data underlying the CFIR constructs provided a nuanced, contextual assessment of implementation, and dissemination outcomes. The CFIR may be valuable in informing the implementation of evidence-based interventions in other parts of Zambia.

Associations among behavioral inhibition and owner-rated attention, hyperactivity/impulsivity, and personality in the domestic dog (Canis familiaris).

In humans, behavioral disinhibition is associated with attention-deficit/hyperactivity disorder (ADHD). Limitations to rodent models of ADHD-like behaviors/symptoms may be augmented by complementary ones, such as the domestic dog. We examined associations between family dogs' (N = 29; of 14 breeds and 12 mongrels) performance on a self-developed touchscreen behavioral Go/No-Go paradigm and their owner-rated inattention and hyperactivity/impulsivity, accounting for relevant covariates. A greater proportion of commission errors was associated with greater hyperactivity/impulsivity. Regardless of accuracy, relative to dogs with no previous training, those with basic training had shorter response latencies. Also, regardless of accuracy, greater confidence and extraversion were associated with shorter latencies, and greater openness was associated with longer latencies. Shorter latency to commission errors was associated with greater inattention. Findings support the dog as a model of the association between behavioral disinhibition and ADHD-like behaviors/symptoms and are early evidence of convergent validity between the behavioral paradigm and the rating scale measure in dogs. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Perceptions of Traumatic Brain Injury (TBI) Among Professionals Providing Drug and Alcohol Addiction Treatment

Traumatic brain injuries (TBI) are a major community health problem in the United States. Traumatic brain injury can result in disruption to normal brain functions and is caused by a bump, blow, or external damage to the head. Ranging from mild to severe in nature, TBIs can result in physical, cognitive, emotional, social, personality, adaptive, and behavioral changes in an individual. These devastating symptoms contribute to individuals with TBIs having the potential for a host of short and long-term issues. Traumatic brain injury can result in cognitive impairments, including disinhibition and risky decision-making behaviors, thus increasing the risk of substance abuse. Because many people do not have visible or physical signs, TBI can be difficult to screen, assess, and diagnose. Despite these difficulties, mental health and substance use disorder professionals can make a positive difference for clients with traumatic brain injury. As such, the current study examines the experiences and perceptions of TBI among treatment staff of Vinland National Center, a substance use disorder treatment facility in Minnesota. Results of this study raise awareness of the challenges of TBI in drug and alcohol treatment centers and offer tips, strategies, and solutions for professionals working with this clientele.

‘I did it for the LULZ’: How the dark personality predicts online disinhibition and aggressive online behavior in adolescence

A large proportion of youth believe that the world of cyberspace provides them with a relatively safe and anonymous digital bubble ripe for uninhibited self-expression. At the same time, observers have noted an increase of individuals behaving in an unrestrained manner on the Internet, while researchers have reported elevated rates of cyber aggressive behavior. What remains unclear, however, is whether, and how, disinhibition might be related to cyber aggression. In an aim to explore the possible associations, a large sample (total N = 709) of high school (Mage = 15.56 years) respondents from New Zealand were recruited, and completed a survey featuring scales assessing personality and technology behaviors, attitudes, habits, and trends. The present study was designed to investigate whether the three dark personality traits of narcissism, psychopathy, and sadism would predict false self perceptions, and in sequence, online disinhibition and aggressive online behavior. All three dark personality traits, as well as false self, were positively associated with online disinhibition. Perceptions of false self were found to be a significant predictor of cyber aggression when mediated by online disinhibition. In the case of cyber aggression, however, psychopathy, sadistic traits, and online disinhibition were found to be significant predictors of this outcome. The results collectively provide a more nuanced understanding of how antisocial personality traits are associated with maladaptive identity formation (i.e., endorsement of false self beliefs) as well as maladaptive online behavior.

Concordance of genetic variation that increases risk for Tourette Syndrome and that influences its underlying neurocircuitry

There have been considerable recent advances in understanding the genetic architecture of Tourette Syndrome (TS) as well as its underlying neurocircuitry. However, the mechanisms by which genetic variation that increases risk for TS—and its main symptom dimensions—influence relevant brain regions are poorly understood. Here we undertook a genome-wide investigation of the overlap between TS genetic risk and genetic influences on the volume of specific subcortical brain structures that have been implicated in TS. We obtained summary statistics for the most recent TS genome-wide association study (GWAS) from the TS Psychiatric Genomics Consortium Working Group (4644 cases and 8695 controls) and GWAS of subcortical volumes from the ENIGMA consortium (30,717 individuals). We also undertook analyses using GWAS summary statistics of key symptom factors in TS, namely social disinhibition and symmetry behaviour. SNP effect concordance analysis (SECA) was used to examine genetic pleiotropy—the same SNP affecting two traits—and concordance—the agreement in single nucelotide polymorphism (SNP) effect directions across these two traits. In addition, a conditional false discovery rate (FDR) analysis was performed, conditioning the TS risk variants on each of the seven subcortical and the intracranial brain volume GWAS. Linkage disequilibrium score regression (LDSR) was used as validation of the SECA method. SECA revealed significant pleiotropy between TS and putamen (p = 2 × 10−4) and caudate (p = 4 × 10−4) volumes, independent of direction of effect, and significant concordance between TS and lower thalamic volume (p = 1 × 10−3). LDSR lent additional support for the association between TS and thalamus volume (p = 5.85 × 10−2). Furthermore, SECA revealed significant evidence of concordance between the social disinhibition symptom dimension and lower thalamus volume (p = 1 × 10−3), as well as concordance between symmetry behaviour and greater putamen volume (p = 7 × 10−4). Conditional FDR analysis further revealed novel variants significantly associated with TS (p < 8 × 10−7) when conditioning on intracranial (rs2708146, q = 0.046; and rs72853320, q = 0.035) and hippocampal (rs1922786, q = 0.001) volumes, respectively. These data indicate concordance for genetic variation involved in disorder risk and subcortical brain volumes in TS. Further work with larger samples is needed to fully delineate the genetic architecture of these disorders and their underlying neurocircuitry.

Disinhibited attachment behavior among infants of mothers with borderline personality disorder, depression, and no diagnosis.

Disinhibited attachment behavior is related to early institutional rearing and to later social maladaptation. It is also seen among infants reared at home whose mothers have histories of child maltreatment or psychiatric hospitalization. However, little is known about the maternal psychiatric diagnoses that might be associated with disinhibited behavior or the mechanisms through which maternal diagnosis might influence infant behavior. In the current study (N = 59), 2 maternal diagnoses, borderline personality disorder (BPD; n = 13) and depression (n = 15), were compared with a no diagnosis group (n = 31) on extent of infant disinhibited behavior. Disinhibited infant behavior was assessed at infant age of 12-18 months using the validated Rating of Infant-Stranger Engagement. Mother-infant interaction was coded using the Atypical Maternal Behavior Instrument for Assessment and Classification. Results indicated that infants of mothers with BPD were significantly more likely to be rated as disinhibited in their behavior toward the stranger compared with infants of mothers with depression and with no diagnosis. Disinhibited behavior was further related to the quality of mother-infant interaction, and maternal frightened/disoriented interaction partially mediated the effect of maternal BPD on infant disinhibited behavior. Disinhibited behavior among previously institutionally reared infants is relatively resistant to intervention after toddlerhood and is associated with maladaptation into adolescence. Therefore, high priority should be placed on understanding the developmental trajectories of home-reared infants with disinhibited behavior and on providing early assessment and early parenting support to mothers with BPD. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

EXAMINING THE IMPACT OF CARDIOVASCULAR RISK FACTORS ON NEUROPSYCHIATRIC SYMPTOMS IN THE PACT-MD STUDY

Introduction Although cardiovascular risk factors (CVRFs) have been identified as important risk factors for both major depression and cognitive decline in later life, their association with neuropsychiatric symptoms (NPS) has not been fully elucidated. Furthermore, CVRFs, particularly hypertension, hypercholesterolemia, and diabetes, may ultimately lead to physical conditions such as small vessel disease known to disrupt cognition, thereby leading to the onset of NPS. Thus, a better understanding of the association between CVRFs and NPS could improve the development of treatments and preventative measures for NPS. Methods Using baseline data from the Prevention of Alzheimer's Dementia with Cognitive Remediation plus Transcranial Direct Current Stimulation (PACt-MD) study, a multi-site intervention study targeting older patients with depression and cognitive decline, we analysed the distribution of CVRFs (Framingham risk scores; Hachinski ischemic score; presence of hypertension, hypercholesterolemia, hyperlipidemia, diabetes, and smoking) in patients with and without NPS as determined by a score of 1 and above or 0 on the Neuropsychiatric Inventory-Questionnaire (NPI-Q). Participants fell into one of the following three diagnosis groups: Mild Cognitive Impairment (MCI) with a lifetime history of major depression (MDD); MCI without MDD; and MDD without MCI. Comparisons of distributions of CVRFs between NPI positive and negative groups were conducted using the non-parametric Mann-Whitney U test at a significance level of Results In a combined sample of 140 participants, there were no significant differences in any CVRF between positive and negative total NPI groups. However, some NPI subscale scores, notably agitation/aggression, anxiety, disinhibition, irritability, and night-time behaviour were significantly associated with increased CVRFs (p Conclusions None of the CVRFs were associated with overall total NPI-Q scores, however, these preliminary analyses suggest that some specific CVRFs were associated with certain NPI-Q subdomains. This suggests that CVRFs contribute to specific NPS domains rather than overall NPS burden. This research was funded by This project has been made possible by Brain Canada through the Canada Brain Research Fund, with the financial support of Health Canada and the Chagnon Family.

Impulsivity Moderates the Relation between Depressive Symptoms and Substance Use across Adolescence

Adolescence is characterized by significant increases in substance use problems. Although early depressive symptoms have been linked to adolescent substance use, recent literature reviews highlight important inconsistencies in these relations that may be accounted for by behavioral disinhibition factors. The current study aims to examine impulsivity as a specific moderator of the relation between early depressive symptoms and trajectories of substance use using a 6-year, prospective longitudinal design. Participants included 247 male and female adolescents (52.5% White, 45% female) who were, on average, 13 years of age at baseline (SD age = 0.90). They completed self-report inventories of depressive symptoms, impulsivity, substance use, and externalizing symptoms. Using a latent growth modeling approach, we found main effects for depressive symptoms and impulsivity, such that youth with lower initial levels of depressive symptoms and higher levels of impulsivity at baseline evidenced greater increases in substance use. Moreover, the interaction between impulsivity and depressive symptoms significantly predicted substance use, indicating that depressive symptoms were more positively related to substance use for youth reporting higher levels of impulsivity. Findings suggest that impulsivity is an important moderator of the relation between depressive symptoms and the development of substance use during adolescence and highlight the need for interventions focusing on both impulsivity and depression in minimizing risk of substance use.

ADHD risk genes involved in dopamine signaling and metabolism are associated with reduced estimated life expectancy at young adult follow-up in hyperactive and control children.

ADHD is associated with an elevated risk of mortality and reduced estimated life expectancy (ELE) by adulthood. Reduced life expectancy is substantially related to the trait of behavioral disinhibition; a correlate of both ADHD and of several dopamine genes related to dopamine signaling and metabolism. We therefore hypothesized that several ADHD risk genes related to dopamine might also be predictive of reduced ELE. Using a longitudinal study of 131 hyperactive children and 71 control cases followed to young adulthood, we examined whether several polymorphisms involving DRD4, DAT1, and DBH were related to ELE. The homozygous 9/9 allele of DAT1 and the heterozygous allele of DBH TaqI were associated with 5- and 2-year reductions, respectively, in total ELE. They did not operate on ELE through any relationships to ADHD specifically or behavioral disinhibition more generally. Instead, they showed links to alcohol use (DBH), reduced education, smoking, and reduced exercise (DAT1) employed in the computation of ELE. We conclude that polymorphisms of two dopamine genes are linked to reductions in ELE independently of their association with ADHD.

The Genetics of Externalizing Problems.

Externalizing problems generally refer to a constellation of behaviors and/or disorders characterized by impulsive action and behavioral disinhibition. Phenotypes on the externalizing spectrum include psychiatric disorders, nonclinical behaviors, and personality characteristics (e.g. alcohol use disorders, other illicit substance use, antisocial behaviors, risky sex, sensation seeking, among others). Research using genetic designs including latent designs from twin and family data and more recent designs using genome-wide data reveal that these behaviors and problems are genetically influenced and largely share a common genetic etiology. Large-scale gene-identification efforts have started to identify robust associations between genetic variants and these phenotypes. However, there is still considerable work to be done. This chapter provides an overview of the current state of research into the genetics of behaviors and disorders on the externalizing spectrum.

Basal Ganglia: Striosomes and the Link between Motivation and Action

The basal ganglia integrate motivation and action across their circuits; neurons in anatomical modules called striosomes could contribute strongly to this merger. A new method focusing on network interconnections will allow a better understanding of the functional role of striosomes.

El consumo de riesgo de alcohol y el riesgo de dependencia al alcohol presentan correlatos neurofisiológicos diferentes

Hazardous alcohol consumption (HAC) is a pattern of alcohol use that may result in harm for the user and/or for those around them. Prior research has suggested that HAC and alcohol dependence share some neurophysiological features but differ in others. To determine whether HAC and alcohol dependence presented different neurophysiological correlates. Two hundred subjects were screened for HAC or alcohol dependence. A quantitative electroencephalo-graphic analysis of delta, theta, alpha and beta absolute power, relative power and mean frequency in subjects with HAC but not alcohol dependence, subjects with risk of alcohol dependence and controls was performed. One hundred and fourteen subjects met inclusion criteria. The HAC group presented with higher beta absolute power and relative power, as well as a lower beta mean frequency than the control group, while the group with risk of alcohol dependence presented lower delta absolute power than controls. HAC and risk of alcohol dependence present different neurophysiological correlates. There is an important effect of the severity of alcohol dependence on neurophysiological correlates of this condition. Our results support the existence of two different types of behavioral disinhibition.