Theory of Mind in Borderline Personality Disorder: A Possible Endophenotypic Factor?

The purpose of this study is to examine whether theory of mind (ToM) is an endophenotypic marker of borderline personality disorder (BPD), thus constituting an etiopathogenic factor of the disease. This would suggest familial vulnerability to BPD. This was a case-control study involving 146 individuals with 57 BPD patients, 32 first-degree relatives, and 57 controls (median age of BPD and control = 33.4 years; relatives = 52.9 years; BPD females and controls = 91.2%; female relatives = 62.5%). All the participants completed the Spanish version of the Movie for the Assessment of Social Cognition test to evaluate the ToM subclassification: interpretation of emotions, thoughts and intentions. BPD patients and their healthy first-degree relatives exhibited significant deficits in the correct interpretation of emotions and intentions compared to healthy controls. Both patients with BPD and their healthy first-degree relatives exhibited significant deficits in ToM, which suggests that it may be an etiopathogenic factor of BPD, and ToM (interpretation of emotions, thoughts and intentions) is a possible endophenotypic marker of BPD, suggesting a genetic predisposition to the disorder. Therefore, ToM could be considered as an indicator for the early detection of the disorder of and intervention for BPD.

Brain networks underlying vulnerability and resilience to drug addiction

Regular drug use can lead to addiction, but not everyone who takes drugs makes this transition. How exactly drugs of abuse interact with individual vulnerability is not fully understood, nor is it clear how individuals defy the risks associated with drugs or addiction vulnerability. We used resting-state functional MRI (fMRI) in 162 participants to characterize risk- and resilience-related changes in corticostriatal functional circuits in individuals exposed to stimulant drugs both with and without clinically diagnosed drug addiction, siblings of addicted individuals, and control volunteers. The likelihood of developing addiction, whether due to familial vulnerability or drug use, was associated with significant hypoconnectivity in orbitofrontal and ventromedial prefrontal cortical-striatal circuits—pathways critically implicated in goal-directed decision-making. By contrast, resilience against a diagnosis of substance use disorder was associated with hyperconnectivity in two networks involving 1) the lateral prefrontal cortex and medial caudate nucleus and 2) the supplementary motor area, superior medial frontal cortex, and putamen—brain circuits respectively implicated in top-down inhibitory control and the regulation of habits. These findings point toward a predisposing vulnerability in the causation of addiction, related to impaired goal-directed actions, as well as countervailing resilience systems implicated in behavioral regulation, and may inform novel strategies for therapeutic and preventative interventions.

Reduced frontostriatal response to expected value and reward prediction error in remitted monozygotic twins with mood disorders and their unaffected high-risk co-twins

Background Depressive episodes experienced in unipolar (UD) and bipolar (BD) disorders are characterized by anhedonia and have been associated with abnormalities in reward processes related to reward valuation and error prediction. It remains however unclear whether these deficits are associated with familial vulnerability to mood disorders. Methods In a functional magnetic resonance imaging study, we evaluated differences in the expected value (EV) and reward prediction error (RPE) signals in ventral striatum (VS) and prefrontal cortex between three groups of monozygotic twins: affected twins in remission for either UD or BD (n = 53), their high-risk unaffected co-twins (n = 34), and low-risk twins with no family history of mood disorders (n = 25). Results Compared to low-risk twins, affected twins showed lower EV signal bilaterally in the frontal poles and lower RPE signal bilaterally in the VS, left frontal pole and superior frontal gyrus. The high-risk group did not show a significant change in the EV or RPE signals in frontostriatal regions, yet both reward signals were consistently lower compared with low-risk twins in all regions where the affected twins showed significant reductions. Conclusion Our findings strengthen the notion that reduced valuation of expected rewards and reduced error-dependent reward learning may underpin core symptom of depression such as loss of interest in rewarding activities. The trend reduction in reward-related signals in unaffected co-twins warrants further investigation of this effect in larger samples and prospective follow-up to confirm possible association with increased familial vulnerability to mood disorders.

Investigating the Evidence of Behavioral, Cognitive, and Psychiatric Endophenotypes in Autism: A Systematic Review

Substantial evidence indicates that parents of autistic individuals often display milder forms of autistic traits referred to as the broader autism phenotype (BAP). To determine if discrete endophenotypes of autism can be identified, we reviewed the literature to assess the evidence of behavioral, cognitive, and psychiatric profiles of the BAP. A systematic review was conducted using EMBASE, MEDLINE, PsycINFO, PsycEXTRA, and Global Health. Sixty papers met our inclusion criteria and results are discussed according to the proportion of studies that yield significant deficits per domain. The behavioral, cognitive, and psychiatric endophenotypes in parents of autistic probands are still not clarified; however, evidence suggests mild social/communication deficits, rigid/aloof personality traits, and pragmatic language difficulties as the most useful sociobehavioral candidate endophenotype traits. The existence of deficits in the cognitive domain does suggest familial vulnerability for autism. Furthermore, increased depressed mood and anxiety can also be useful markers; however, findings should be interpreted with caution because of the small number of studies in such heterogeneously broad domains and several methodological limitations.

Antisocial Alcoholism in Parents of Adolescents and Young Adults With Childhood ADHD

Objective: Test the hypothesis that alcoholism, including antisocial alcoholism, is more prevalent among mothers and fathers of children with versus without ADHD. Method: Mothers (312 ADHD group, 235 non-ADHD group) and fathers (291 ADHD group, 227 non-ADHD group) in the Pittsburgh ADHD Longitudinal Study were interviewed along with their adolescent and young adult offspring. Results: Maternal and paternal alcoholism, with and without comorbid antisociality, was more prevalent in the ADHD group. Paternal alcoholism without antisociality was only marginally higher for probands after controlling for paternal ADHD. Offspring conduct disorder comorbidity was associated with parental antisociality but not parental antisocial alcoholism. Conclusion: Our findings that 44% of proband fathers and 25% of proband mothers experienced alcohol problems with or without antisociality are further evidence of increased alcoholism prevalence in families affected by ADHD. Maternal alcoholism and antisociality are prominent contributors to this family-level vulnerability. These findings indicate the need to assess long-term offspring outcomes as a function of parental alcohol and externalizing comorbidities, and perhaps other indicators of parental alcoholism phenotype, as familial vulnerability unfolds across development.

Reactivity to uncertain threat as a familial vulnerability factor for alcohol use disorder

BackgroundWhen sober, problematic drinkers display exaggerated reactivity to threats that are uncertain (U-threat). Since this aversive affective state can be alleviated via acute alcohol intoxication, it has been posited that individuals who exhibit heightened reactivity to U-threat at baseline are motivated to use alcohol as a means of avoidance-based coping, setting the stage for excessive drinking. To date, however, no study has attempted to characterize the dispositional nature of exaggerated reactivity to U-threat and test whether it is a vulnerability factor or exclusively a disease marker of problematic alcohol use.MethodThe current investigation utilized a family study design to address these gaps by examining whether (1) reactivity to U-threat is associated with risk for problematic alcohol use, defined by family history of alcohol use disorder (AUD) and (2) reactivity to U-threat is correlated amongst adult biological siblings. A total of 157 families, and 458 individuals, participated in the study and two biological siblings completed a threat-of-shock task designed to probe reactivity to U-threat and predictable threat (P-threat). Startle potentiation was collected as an index of aversive responding.ResultsWithin biological siblings, startle potentiation to U-threat [intraclass correlation (ICC) = 0.35] and P-threat (ICC = 0.63) was significantly correlated. In addition, independent of an individuals’ own AUD status, startle potentiation to U-threat, but not P-threat, was positively associated with risk for AUD (i.e. AUD family history).ConclusionThis suggests that heightened reactivity to U-threat may be a familial vulnerability factor for problematic drinking and a novel prevention target for AUD.