RESUMO
Altered autobiographical memory (ABM) processing characterizes some individuals with experiences of childhood maltreatment. This fMRI study of ABM processing evaluated potential developmental plasticity in neural functioning following maltreatment. Adolescents with (N = 19; MT group) and without (N = 18; Non-MT group) documented childhood maltreatment recalled specific ABMs in response to emotionally valenced cue words during fMRI at baseline (age 12.71 ± 1.48) and follow-up (14.88 ± 1.53 years). Psychological assessments were collected at both timepoints. Longitudinal analyses were carried out with BOLD signal changes during ABM recall and psychopathology to investigate change over time. In both groups there was relative stability of the ABM brain network, with some developmental maturational changes observed in cortical midline structures (ventromedial PFC (vmPFC), posterior cingulate cortex (pCC), and retrosplenial cortex (rSC). Significantly increased activation of the right rSC was observed only in the MT group, which was associated with improved psychological functioning. Baseline group differences in relation to hippocampal functioning, were not detected at follow-up. This study provides preliminary empirical evidence of functional developmental plasticity in children with documented maltreatment experience using fMRI. This suggests that altered patterns of brain function, associated with maltreatment experience, are not fixed and may reflect the potential to track a neural basis of resilience.
Assuntos
Imageamento por Ressonância Magnética , Memória Episódica , Adolescente , Criança , Humanos , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Rememoração Mental/fisiologia , Plasticidade NeuronalRESUMO
Psychopathy is an adult condition that incurs substantial societal and individual costs. Here we review neurocognitive and genetically informative studies that shed light on how and why this condition emerges. Children cannot present with psychopathy. However, the presence of callous-unemotional (CU) traits can distinguish a group of children who are at elevated risk of psychopathy in adulthood. These children display diminished empathy and guilt and show attenuated brain activation to distress cues in others. Genetically informative studies indicate that individual differences in CU traits show moderate-to-strong heritability, but that protective environmental factors can counter heritable risk. On the basis of the extant research findings, we speculate on what might represent the priorities for research over the next decade. We also consider the clinical implications of these research findings. In particular, we consider the importance of delineating what precisely works for children with CU traits (and their parents) and the ways in which intervention and prevention programs may be optimized to improve engagement as well as clinical outcomes.
Assuntos
Transtorno da Personalidade Antissocial/psicologia , Transtorno da Conduta/psicologia , Emoções , Pais/psicologia , Adulto , Transtorno da Personalidade Antissocial/prevenção & controle , Criança , Transtorno da Conduta/prevenção & controle , Empatia , Culpa , HumanosRESUMO
BACKGROUND: A Callous-Unemotional trait specifier (termed 'Limited Prosocial Emotions') was added to the diagnosis of conduct disorder in DSM-5. The Inventory of Callous-Unemotional Traits (ICU) is a comprehensive measure of these traits assessing three distinct, yet correlated dimensions--Callousness, Uncaring, and Unemotional--all thought to reflect the general Callous-Unemotional construct. The present study was the first to examine the degree to which the aetiology of these dimensions is shared v. independent. METHOD: Parent-reported ICU data from 5092 16-year-old twin pairs from the Twins Early Development Study were subjected to confirmatory factor analysis. Multivariate genetic modelling was applied to the best-fitting structure. RESULTS: A general-specific structure, retaining a general factor and two uncorrelated specific factors (Callousness-Uncaring, Unemotional), provided the best fit to the data. The general factor was substantially heritable (h2 = 0.58, 95% CI 0.51-0.65). Unusually, shared environmental influences were also important in accounting for this general factor (c2 = 0.26, 95% CI 0.22-0.31), in addition to non-shared environmental influences. The Unemotional dimension appeared phenotypically and genetically distinct as shown by the substantial loadings of unemotional items on a separate dimension and a low genetic correlation between Unemotional and Callousness-Uncaring. CONCLUSIONS: A general factor, indicative of a shared phenotypic structure across the dimensions of the ICU was under substantial common genetic and more modest shared environment influences. Our findings also suggest that the relevance of the Unemotional dimension as part of a comprehensive assessment of CU traits should be investigated further.
Assuntos
Transtorno da Personalidade Antissocial/genética , Transtorno da Conduta/genética , Personalidade/genética , Gêmeos Dizigóticos/genética , Gêmeos Monozigóticos/genética , Adolescente , Transtorno da Personalidade Antissocial/psicologia , Transtorno da Conduta/psicologia , Emoções , Empatia , Análise Fatorial , Feminino , Humanos , Masculino , Pais , Inventário de Personalidade , Gêmeos Dizigóticos/psicologia , Gêmeos Monozigóticos/psicologia , Reino UnidoRESUMO
BACKGROUND: Childhood maltreatment (CM) has been associated with increased risk of attention deficit hyperactivity disorder (ADHD) in children and adults. It is, however, unclear whether this association is causal or due to familial confounding. METHOD: Data from 18 168 adult twins, aged 20-46 years, were drawn from the population-based Swedish twin registry. Retrospective self-ratings of CM (emotional and physical neglect, physical and sexual abuse and witnessing family violence), and self-ratings for DSM-IV ADHD symptoms in adulthood were analysed. Possible familial confounding was investigated using a within twin-pair design based on monozygotic (MZ) and dizygotic (DZ) twins. RESULTS: CM was significantly associated with increased levels of ADHD symptom scores in adults [regression coefficient: 0.40 standard deviations, 95% confidence interval (CI) 0.37-0.43]. Within twin-pair analyses showed attenuated but significant estimates within DZ (0.29, 95% CI 0.21-0.36) and MZ (0.18, 95% CI 0.10-0.25) twin pairs. Similar results emerged for hyperactive/impulsive and inattentive ADHD symptom scores separately in association with CM. We conducted sensitivity analyses for early maltreatment, before age 7, and for abuse and neglect separately, and found similarly reduced estimates in DZ and MZ pairs. Re-traumatization after age 7 did not significantly influence results. CONCLUSIONS: CM was significantly associated with increased ADHD symptoms in adults. Associations were partly due to familial confounding, but also consistent with a causal interpretation. Our findings support cognitive neuroscience studies investigating neural pathways through which exposure to CM may influence ADHD. Clinicians treating adults with ADHD should be aware of the association with maltreatment.
Assuntos
Sobreviventes Adultos de Maus-Tratos Infantis , Transtorno do Deficit de Atenção com Hiperatividade/etiologia , Sistema de Registros , Adulto , Sobreviventes Adultos de Maus-Tratos Infantis/estatística & dados numéricos , Transtorno do Deficit de Atenção com Hiperatividade/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Suécia/epidemiologia , Adulto JovemRESUMO
BACKGROUND: Children with conduct problems (CP) are a heterogeneous group. Those with high levels of callous-unemotional traits (CP/HCU) appear emotionally under-reactive at behavioural and neural levels whereas those with low levels of CU traits (CP/LCU) appear emotionally over-reactive, compared with typically developing (TD) controls. Investigating the degree to which these patterns of emotional reactivity are malleable may have important translational implications. Instructing participants with CP/HCU to focus on the eyes of fearful faces (i.e. the most salient feature) can ameliorate their fear-recognition deficits, but it is unknown whether this is mediated by amygdala response. It is also unknown whether focusing on fearful eyes is associated with increased amygdala reactivity in CP/LCU. METHOD: Functional magnetic resonance imaging (fMRI) was used to measure neural responses to fearful and calm faces in children with CP/HCU, CP/LCU and TD controls (n = 17 per group). On half of trials participants looked for a blue dot anywhere within target faces; on the other half, participants were directed to focus on the eye region. RESULTS: Reaction time (RT) data showed that CP/LCU were selectively slowed in the fear/eyes condition. For the same condition, CP/LCU also showed increased amygdala and subgenual anterior cingulate cortex (sgACC)/orbitofrontal cortex (OFC) responses compared with TD controls. RT and amygdala response to fear/eyes were correlated in CP/LCU only. No effects of focusing on the eye region were observed in CP/HCU. CONCLUSIONS: These data extend the evidence base suggesting that CU traits index meaningful heterogeneity in conduct problems. Focusing on regulating reactive emotional responses may be a fruitful strategy for children with CP/LCU.
Assuntos
Tonsila do Cerebelo/fisiopatologia , Transtorno da Conduta/fisiopatologia , Expressão Facial , Medo , Lobo Frontal/fisiopatologia , Giro do Cíngulo/fisiopatologia , Adolescente , Encéfalo/fisiopatologia , Estudos de Casos e Controles , Criança , Emoções , Olho , Neuroimagem Funcional , Humanos , Imageamento por Ressonância Magnética , Masculino , Tempo de Reação , Reconhecimento PsicológicoRESUMO
Childhood callous-unemotional (CU) traits are characterized by low empathy, limited prosocial behavior, and restricted social affiliation. However, few studies have investigated whether CU traits are associated with different subtypes of prosocial and affiliative behavior or the specific motivational difficulties underlying these behaviors. We addressed these questions using data from 135 young children (M = 5.48 years old; 58% female) who viewed depictions of adults or children in instrumental need, emotional need, or neutral situations. We assessed recognition, suggested initiation of, and motivation for prosocial or affiliative behavior in response to each depiction. We distinguished between subtypes of prosocial (instrumental and emotional) and affiliative (parallel, cooperative, associative) behavior, as well as self- versus other-orientated motivations. Parents reported on child CU traits and conduct problems. Overall, children accurately recognized prosocial and neutral situations, offered help, and expressed other-orientated motivations for prosocial behavior and social motivations for affiliative behavior. Higher CU traits were related to lower overall recognition accuracy, which was more pronounced for emotional need. Higher CU traits were also related to fewer offers of help and more denial of prosocial behavior, particularly for instrumental need. Finally, CU traits were related to lower probability of initiating affiliative behavior. CU traits were not differentially related to self- versus other-orientated motivations for prosocial or affiliative behavior. Findings demonstrate difficulties of children with CU traits in recognizing need and offering help. Interventions for CU traits could include modules that explicitly scaffold and shape prosociality and social affiliation.
Assuntos
Comportamento Infantil , Emoções , Empatia , Motivação , Comportamento Social , Humanos , Feminino , Masculino , Pré-Escolar , Criança , Comportamento Infantil/psicologia , Transtorno da Conduta/psicologiaRESUMO
Schizophrenia is a neurodevelopmental disorder, and risk genes are thought to act through disruption of brain development. Several genetic studies have identified dystrobrevin binding protein 1 (DTNBP1, also known as dysbindin) as a potential susceptibility gene for schizophrenia, but its impact on brain function is poorly understood. It has been proposed that DTNBP1 may be associated with differences in visual processing. To test this, we examined the impact on visual processing in 61 healthy children aged 10-12 years of a genetic variant in DTNBP1 (rs2619538) that was common to all schizophrenia associated haplotypes in an earlier UK-Irish study. We tested the hypothesis that carriers of the risk allele would show altered occipital cortical function relative to noncarriers. Functional Magnetic Resonance Imaging (fMRI) was used to measure brain responses during a visual matching task. The data were analysed using statistical parametric mapping and statistical inferences were made at p<0.05 (corrected for multiple comparisons). Relative to noncarriers, carriers of the risk allele had greater activation in the lingual, fusiform gyrus and inferior occipital gyri. In these regions DTNBP1 genotype accounted for 19%, 20% and 14% of the inter-individual variance, respectively. Our results suggest that that genetic variation in DTNBP1 is associated with differences in the function of brain areas that mediate visual processing, and that these effects are evident in young children. These findings are consistent with the notion that the DTNBP1 gene influences brain development and can thereby modulate vulnerability to schizophrenia.
Assuntos
Encéfalo/fisiologia , Proteínas de Transporte/genética , Proteínas de Transporte/fisiologia , Percepção Visual/genética , Percepção Visual/fisiologia , Alelos , Criança , Cognição/fisiologia , DNA/genética , Disbindina , Proteínas Associadas à Distrofina , Expressão Gênica/fisiologia , Genótipo , Haplótipos , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Lobo Occipital/metabolismo , Lobo Occipital/fisiologia , Polimorfismo de Nucleotídeo Único , Desempenho Psicomotor/fisiologia , Risco , Esquizofrenia/genética , Psicologia do EsquizofrênicoRESUMO
Epigenetic processes have been implicated in addiction; yet, it remains unclear whether these represent a risk factor and/or a consequence of substance use. Here, we believe we conducted the first genome-wide, longitudinal study to investigate whether DNA methylation patterns in early life prospectively associate with substance use in adolescence. The sample comprised of 244 youth (51% female) from the Avon Longitudinal Study of Parents and Children (ALSPAC), with repeated assessments of DNA methylation (Illumina 450k array; cord blood at birth, whole blood at age 7) and substance use (tobacco, alcohol and cannabis use; age 14-18). We found that, at birth, epigenetic variation across a tightly interconnected genetic network (n=65 loci; q<0.05) associated with greater levels of substance use during adolescence, as well as an earlier age of onset amongst users. Associations were specific to the neonatal period and not observed at age 7. Key annotated genes included PACSIN1, NEUROD4 and NTRK2, implicated in neurodevelopmental processes. Several of the identified loci were associated with known methylation quantitative trait loci, and consequently likely to be under significant genetic control. Collectively, these 65 loci were also found to partially mediate the effect of prenatal maternal tobacco smoking on adolescent substance use. Together, findings lend novel insights into epigenetic correlates of substance use, highlight birth as a potentially sensitive window of biological vulnerability and provide preliminary evidence of an indirect epigenetic pathway linking prenatal tobacco exposure and adolescent substance use.
Assuntos
Consumo de Bebidas Alcoólicas/genética , Metilação de DNA , Epigênese Genética/genética , Genoma Humano/genética , Abuso de Maconha/genética , Fumar/genética , Adolescente , Criança , Pré-Escolar , Feminino , Estudo de Associação Genômica Ampla , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Masculino , Proteínas do Tecido Nervoso/genética , Gravidez , Estudos Prospectivos , RiscoRESUMO
Adolescents are often sensitive to peer rejection, a factor that might contribute to the risk of affective disorder in this age group. Previous studies suggest a significant overlap among socioaffective brain regions involved in the response to social rejection, regions continuing to develop functionally during adolescence and regions influenced by monoamine oxidase A (MAOA) polymorphism. The current study investigated whether the neural response to social rejection is functionally immature in adolescents compared with adults, and whether these responses are modulated by MAOA genotype. Blood-oxygen-level-dependent response was measured with functional magnetic resonance imaging during a rejection-themed emotional Stroop task in 19 adolescents (aged 14-16) and 16 adults (aged 23-28) genotyped for MAOA polymorphism. Similar numbers of MAOA-L and MAOA-H carriers were recruited to maximize power to detect genotype effects. Main effects of rejection stimuli (relative to neutral and acceptance control stimuli) were seen in predicted socioaffective brain regions. Adolescents did not show the adult pattern of modulation by rejection stimuli in the right ventrolateral prefrontal cortex, suggesting continued functional maturation of this regulatory region during adolescence. Age and genotype interacted in the left amygdala, in which the predicted effect of genotype on responses to rejection stimuli was seen in the adults, but not in the adolescents. The data suggest continued functional development of the circuitry underlying the processing of social rejection between adolescence and adulthood, and show that the effects of MAOA genotype on neural responses may vary with age.