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1.
Addict Biol ; 26(1): e12885, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32135572

RESUMO

Two of the most commonly used substances by adolescents in the United States are cannabis and alcohol. Cannabis use disorder (CUD) and alcohol use disorder (AUD) are associated with impairments in decision-making processes. One mechanism for impaired decision-making in these individuals is thought to be an inability to adequately represent future events during decision-making. In the current study involving 112 adolescents, we used a comparative optimism task to examine the relationship between relative severity of CUD/AUD (as indexed by the CUD/AUD Identification Tests [CUDIT/AUDIT]) and atypical function within neural systems underlying affect-based neural represenation future events. Greater CUDIT scores were negatively related to responses within subgenual anterior and posterior cingulate cortex when processing high-intensity potential future positive and negative events. There was also a particularly marked negative relationship between CUD symptoms and blood oxygen level-dependent (BOLD) responses within visual and premotor cortices to high-intensity, negatively valenced potential future events. However, AUD symptom severity was not associated with dysfunction within these brain regions. These data indicate that relative risk/severity of CUD is associated with reduced responsiveness to future high-intensity events. This may impair decision-making where future significant consequences should guide response choice.

2.
Brain Behav ; 11(2): e01994, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33369286

RESUMO

BACKGROUND: Generalized anxiety disorder (GAD) can significantly impair quality of life and is associated with a relatively poor long-term prognosis. Anxiety disorders are often associated with hyper-responsiveness to threat, perhaps coupled with impaired executive functioning. However, GAD, particularly adolescent GAD, has been the focus of little functional neuroimaging work compared to other anxiety disorders. Here, we examine the neural association of adolescent GAD with responsiveness to threat and response control. METHODS: The study involved 35 adolescents with GAD and 34 healthy comparison individuals (N = 69) matched on age, gender, and IQ. Participants were scanned during an affective number Stroop task. RESULTS: We found significant Group-by-Task Condition interactions in regions involved in response control/motor responding (bilateral precentral gyri and cerebellum) and/or cognitive control/attention (dorsomedial and lateral frontal cortex, posterior cingulate cortex, cuneus, and precuneus). In line with predictions, the youth with GAD showed significantly less recruitment during task trials than the healthy comparison individuals. However, no indications of specific heightened responses to threat were seen. CONCLUSIONS: GAD involves reduced capacity for engaging regions involved in response control/motor responding and/or cognitive control/attention. This might reflect either a secondary consequence of the patient's worry or an early risk factor for the development of worry.

3.
PLoS One ; 15(12): e0243527, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33301508

RESUMO

The biggest nationwide COVID-19 pandemic lockdown worldwide was enforced in India for an initial period of 21-days. Emerging evidence suggests that pandemic situations and associated lockdowns have an adverse impact on sleep and mental health. However, prediction of sleep health from sociodemographic characteristics and the public's worry during the initial stages of the COVID-19 pandemic has not been extensively explored so far. It's also unclear whether sleep outcomes mediate the association between worry and mental health during pandemic situations. A web-survey (N = 391) on sociodemographic characteristics, COVID-19 related worry, sleep health (insomnia and daytime sleepiness), and depression was conducted during the initial 21-days of the COVID-19 stringent lockdown in India. Multiple regression analyses showed that variables, including sex, age, income level, and worry score, contributed to the significant regression equation for insomnia but not for daytime sleepiness. Specifically, the female, younger, lower income, and highly worried populations contributed significantly more than the male, elderly, higher income, and less worried populations, respectively, to the prediction of insomnia. Mediation analyses showed that insomnia, but not daytime sleepiness, fully mediated the relationship between worry score and severity of depressive symptoms. We provide evidence that the female, younger, lower income, and worried populations may be at higher risk for insomnia during pandemic situations. Current evidence gives hope that improving sleep may reduce depressive symptoms during a pandemic situation. This underscores the importance of the implementation of effective public health policies in conjunction with strategical responses to the COVID-19 pandemic.

5.
J Child Adolesc Psychopharmacol ; 30(9): 542-548, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32882144

RESUMO

Objectives: Temporal reward discounting impulsivity (TDI) reflects a propensity to choose smaller immediate rather than larger delayed rewards relative to age/IQ-matched peers. Previous work with adults has linked TDI to an increased risk for antisocial behavior but also psychopathology in general. However, little work has examined TDI in adolescents with conduct disorder (CD), or considered whether TDI might be associated dimensionally with traits associated with antisocial behavior, that is, impulsivity, irritability, and/or callous-unemotional traits. In this study TDI was investigated in a large adolescent group with varying levels of antisocial behavior. Methods: Participants consisted of 195 adolescents (67 with CD, 77 in a psychiatric comparison group and 51 typically developing adolescents). Participants performed a temporal discounting task and individual differences were measured through the Connors rating scale for attention-deficit/hyperactivity disorder (impulsivity), Affective Reactivity Index (irritability), and Inventory of Callous-Unemotional traits. Results: The adolescents with CD and those in the psychiatric comparison group showed significantly greater TDI than typically developing adolescents. However, these group differences were abolished when dimensional covariates were included. Irritability was significantly associated with TDI. Conclusions: We conclude that TDI reflects a transdiagnostic form of dysfunction that particularly manifests in adolescents with increased irritability.

6.
Front Psychiatry ; 11: 345, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612545

RESUMO

Childhood sexual abuse is associated with significant subsequent pathology and neurodevelopmental disruption. In particular, childhood sexual abuse has been associated with heightened threat sensitivity. However, little work has directly investigated this issue. In this study, we examine the association of childhood sexual abuse to neural and behavioral responses to looming, threatening face stimuli. The study involved 23 adolescents with significant past sexual abuse and 24 comparison individuals matched on IQ, age, and sex. Participants were scanned during a looming threat task that involved negative and neutral, human faces and animals that appeared to either loom toward or recede from the participant. We found that adolescents who had been previously subjected to sexual abuse, relative to comparison adolescents, showed increased neural responses to threatening looming stimuli in regions including rostral and superior frontal gyrus as well as posterior cingulate gyrus. In addition, they were significantly more slowed by looming stimuli, particularly if these were human faces, than adolescents who had not been exposed. These data demonstrate that prior sexual abuse was associated with heightened neural responsiveness to looming threats in a series of regions beyond the amygdala. These data are interpreted within models of rostromedial frontal and posterior cingulate cortices that stress their role in self-referential emotional processing and emotional maintenance.

7.
Hum Brain Mapp ; 2020 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-32596977

RESUMO

The ENIGMA group on Generalized Anxiety Disorder (ENIGMA-Anxiety/GAD) is part of a broader effort to investigate anxiety disorders using imaging and genetic data across multiple sites worldwide. The group is actively conducting a mega-analysis of a large number of brain structural scans. In this process, the group was confronted with many methodological challenges related to study planning and implementation, between-country transfer of subject-level data, quality control of a considerable amount of imaging data, and choices related to statistical methods and efficient use of resources. This report summarizes the background information and rationale for the various methodological decisions, as well as the approach taken to implement them. The goal is to document the approach and help guide other research groups working with large brain imaging data sets as they develop their own analytic pipelines for mega-analyses.

8.
Psychol Med ; : 1-11, 2020 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-32584213

RESUMO

BACKGROUND: Irritability and anxiety frequently co-occur in pediatric populations. Studies separately looking at the neural correlates of these symptoms have identified engagement of similar neural systems - particularly those implicated in emotional processing. Both irritability and anxiety can be considered negative valence emotional states that might relate to emotion dysregulation. However, previous work has not examined the neural responding during the performance of an emotion regulation task as a function of interaction between irritability and anxiety simultaneously. METHODS: This fMRI study involved 155 participants (90 with significant psychopathologies and 92 male) who performed the Affective Stroop Task, designed to engage emotion regulation as a function of task demands. The Affective Reactivity Index (ARI) was used to index irritability and the Screen for Child Anxiety Related Emotional Disorders (SCARED) was used to index anxiety. RESULTS: Levels of irritability, but not anxiety, was positively correlated with responses to visual images within the right rostro-medial prefrontal cortex and left anterior cingulate cortex during view trials. The second region of ventral anterior cingulate cortex showed a condition-by-emotion-by-ARI score-by-SCARED score interaction. Specifically, anxiety level was significantly correlated with a decreased differential BOLD response to negative relative to neutral view trials but only in the presence of relatively high irritability. CONCLUSIONS: Atypical maintenance of emotional stimuli within the rostro-medial prefrontal cortex may exacerbate the difficulties faced by adolescents with irritability. Moreover, increased anxiety combined with significant irritability may disrupt an automatic emotional conflict-based form of emotion regulation that is particularly associated with the ventral anterior cingulate cortex.

9.
Artigo em Inglês | MEDLINE | ID: mdl-32299790

RESUMO

BACKGROUND: The two most commonly used illegal substances by adolescents in the United States are alcohol and cannabis. Alcohol use disorder (AUD) and cannabis use disorder (CUD) have been associated with dysfunction in decision-making processes in adolescents. One potential mechanism for these impairments is thought to be related to abnormalities in reward and punishment processing. However, very little work has directly examined potential differential relationships between AUD and CUD symptom severity and neural dysfunction during decision making in adolescents. METHODS: In the current study, 154 youths participated in a passive avoidance learning task during functional magnetic resonance imaging to investigate the relationship between relative severity of AUD/CUD and dysfunction in processing reward and punishment feedback. RESULTS: Increasing Alcohol Use Disorder Identification Test scores were associated with reduced neural differentiation between reward and punishment feedback within regions of striatum, posterior cingulate cortex, and parietal cortex. However, increasing Cannabis Use Disorder Identification Test scores were not associated with any neural dysfunction during the passive avoidance task. CONCLUSIONS: These data expand on emerging literature that relative severity of AUD is associated with reduced responsivity to rewards in adolescents and that there are differential associations between AUD and CUD symptoms and neurocircuitry dysfunction in the developing adolescent brain.

10.
Eur J Neurosci ; 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31738835

RESUMO

Patients with anxiety disorders suffer from impaired concentration, potentially as a result of stronger emotional interference on attention. Studies using behavioural measures provide conflicting support for this hypothesis. Elevated state anxiety may be necessary to reliably document differences in emotional interference in patients versus healthy controls. The present study examines the effect of experimentally induced state anxiety (threat-of-shock) on attention interference by emotional stimuli. Anxiety patients (n = 36) and healthy controls (n = 32) completed a modified affective Stroop task during periods of safety and threat-of-shock. Results indicated that in both patients and controls, threat decreased negative, but not positive or neutral, emotional interference on attention (both p < .001). This finding supports a threat-related narrowing of attention whereby a certain level of anxiety decreases task-irrelevant processing.

11.
Psychiatry Res Neuroimaging ; 292: 62-71, 2019 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-31541926

RESUMO

Despite extensive behavioral evidence of impairments in face processing and expression recognition in adults with alcohol or cannabis use disorders (AUD/CUD), neuroimaging findings have been inconsistent. Moreover, relatively little work has examined the relationship of AUD or CUD symptoms with face or expression processing within adolescents. Given the high prevalence of alcohol and cannabis use during adolescence, understanding how these usage behaviors interact with neural mechanisms supporting face and expression processing could have important implications for youth social and emotional functioning. In this study, adolescents (N = 104) responded to morphed fearful and happy expressions during fMRI and their level of AUD and/or CUD symptoms were related to the BOLD response data. We found that AUD and CUD symptom severity were both negatively related to responses to faces generally. However, whereas this relationship was shown for AUD within ventromedial prefrontal cortex and lingual gyrus, it was shown for CUD within rostromedial prefrontal cortex including anterior cingulate cortex. Additionally, AUD symptom levels were associated with differential responses within medial temporal pole and inferior parietal lobule as a function of expression. These results have potential implications for understanding the social and emotional functioning of adolescents with AUD and CUD symptoms.


Assuntos
Comportamento do Adolescente/fisiologia , Comportamento do Adolescente/psicologia , Alcoolismo/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Reconhecimento Facial/fisiologia , Abuso de Maconha/diagnóstico por imagem , Adolescente , Alcoolismo/psicologia , Encéfalo/fisiopatologia , Emoções/fisiologia , Feminino , Seguimentos , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Abuso de Maconha/psicologia
12.
J Child Adolesc Psychopharmacol ; 29(7): 526-534, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31170004

RESUMO

Objective: Two of the most commonly abused substances by adolescents in the United States are alcohol and cannabis, both of which are associated with adverse medical and psychiatric outcomes throughout the lifespan. Both are assumed to impact the development of emotional processing although findings on the direction of this impact have been mixed. Preclinical animal work and some functional magnetic resonance imaging (fMRI) work with humans have suggested cannabis use disorder (CUD) and alcohol use disorder (AUD) are associated with increased threat responsiveness. However, other fMRI work has indicated CUD/AUD are associated with diminished threat responsiveness. In this study, we report on a study examining the relationship of severity of CUD/AUD and threat responsiveness in an adolescent population. Methods: The study involved 87 (43 male) adolescents with varying levels of CUD/AUD symptomatology (N = 45 above clinical cutoffs for CUD or AUD). They were scanned with fMRI during a looming threat task that involved images of threatening and neutral human faces or animals that appeared to be either looming or receding. Results: Increasing levels of CUD symptomatology were associated with decreased responding to looming stimuli within regions, including rostral frontal and fusiform gyrus as well as the amygdala. There were no relationships with AUD symptomatology. Conclusions: These data indicate that CUD in particular is associated with a decrease in responsiveness to the looming threat cue possibly relating to the putative neurotoxic impact of cannabis abuse.


Assuntos
Alcoolismo/psicologia , Emoções/fisiologia , Abuso de Maconha/psicologia , Adolescente , Alcoolismo/fisiopatologia , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Abuso de Maconha/fisiopatologia , Índice de Gravidade de Doença , Estados Unidos
13.
JAMA Netw Open ; 2(5): e194604, 2019 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-31125109

RESUMO

Importance: Childhood maltreatment is associated with serious developmental consequences that may be different depending on the form of maltreatment. However, relatively little research has investigated this issue despite implications for understanding the development of psychiatric disorders after maltreatment. Objective: To determine the association of childhood maltreatment and potential differential associations of childhood abuse or neglect with neural responsiveness within regions of the brain implicated in emotional responding and response control. Design, Setting, and Participants: In this cross-sectional study, participants aged 10 to 18 years with varying levels of prior maltreatment as indexed by the Childhood Trauma Questionnaire (CTQ) were recruited from a residential care facility and the surrounding community. Blood oxygen level-dependent response data were analyzed via 2 analyses of covariance that examined 2 (sex) × 3 (task condition [view, congruent, incongruent]) × 3 (valence [negative, neutral, positive]) with Blom-transformed covariates: (1) total CTQ score; and (2) abuse and neglect subscores. Data were collected from April 1, 2016, to June 30, 2018. Data analyses occurred from June 10, 2018, to October 31, 2018. Main Outcomes and Measures: Blood oxygenation level-dependent signals in response to an Affective Stroop task were measured via functional magnetic resonance imaging. Results: The sample included 116 youths (mean [SD] age, 15.0 [2.2] years; 70 [60.3%] male). Fifteen participants reported no prior maltreatment. The remaining 101 participants (87.1%) reported at least some prior maltreatment, and 55 (54.5%) reported significant maltreatment, ie, total CTQ scores were greater than the validated CTQ score threshold of 40. There were significant total CTQ score × task condition associations within the bilateral postcentral gyrus, left precentral gyrus, midcingulate cortex, middle temporal gyrus, and superior temporal gyrus (left postcentral gyrus: F = 11.73; partial η2 = 0.14; right postcentral and precentral gyrus: F = 9.81; partial η2 = 0.10; midcingulate cortex: F = 12.76; partial η2 = 0.12; middle temporal gyrus: F = 13.24; partial η2 = 0.10; superior temporal gyrus: F = 10.33; partial η2 = 0.11). In all examined regions of the brain, increased maltreatment was associated with decreased differential responsiveness to incongruent task trials compared with view trials (left postcentral gyrus: r = -0.34; 95% CI, -0.17 to -0.51; right postcentral and precentral gyrus: r = -0.31; 95% CI, -0.14 to -0.49; midcingulate cortex: r = -0.36; 95% CI, -0.18 to -0.53; middle temporal gyrus: r = -0.35; 95% CI, -0.17 to -0.52; superior temporal gyrus: r = -0.37; 95% CI, -0.20 to -0.55). These interactions were particularly associated with level of abuse rather than neglect. A second analysis of covariance revealed significant abuse × task condition (but not neglect × task) interactions within the midcingulate cortex (F = 13.96; partial η2 = 0.11), right postcentral gyrus and inferior parietal lobule (F = 15.21; partial η2 = 0.12), left postcentral and precentral gyri (F = 11.16; partial η2 = 0.12), and rostromedial frontal cortex (F = 10.36; partial η2 = 0.08)). In all examined regions of the brain, increased abuse was associated with decreased differential responsiveness to incongruent task trials compared with view trials (midcingulate cortex: partial r = -0.33; P < .001; right postcentral gyrus and inferior parietal lobule: partial r = -0.41; P < .001; left postcentral and precentral gyri: partial r = -0.40; P < .001; and rostromedial frontal cortex: partial r = -0.40; P < .001). Conclusions and Relevance: These data document associations of different forms of childhood maltreatment with atypical neural response. This suggests that forms of maltreatment may differentially influence the development of psychiatric pathology.


Assuntos
Encéfalo/fisiopatologia , Maus-Tratos Infantis/psicologia , Regulação Emocional/fisiologia , Função Executiva/fisiologia , Adolescente , Encéfalo/diagnóstico por imagem , Criança , Estudos Transversais , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Oxigênio/sangue , Desempenho Psicomotor , Inquéritos e Questionários
14.
Dev Cogn Neurosci ; 36: 100618, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30710868

RESUMO

Alcohol and cannabis are two of the most commonly used substances by adolescents and are associated with adverse medical and psychiatric outcomes. These adverse psychiatric outcomes may reflect the negative impact of alcohol and/or cannabis abuse on neural systems mediating reward and/or error detection. However, work indicative of this has mostly been conducted in adults with Alcohol and/or Cannabis Use Disorder (i.e., AUD and CUD), with relatively little work in adolescent patients. Furthermore, of the work that has been conducted in adolescents, groups were based on categorical diagnoses of AUD and/or CUD, so the relationship between AUD and/or CUD symptom severity in adolescents and neural dysfunction is unclear. We used a Monetary Incentive Delay (MID) task to examine the relationship between AUDIT and/or CUDIT scores and functional integrity of neuro-circuitries mediating reward processing and error detection within 150 adolescents. Our findings indicate that AUDIT score is negatively related to activity in reward processing neuro-circuitry in adolescents. However, CUDIT score is negatively related to activity in brain regions involved in error detection. Each of these relationships reflected a medium effect size (Partial-η2 0.09-0.14). These data suggest differential impacts of AUD and CUD on reward versus error detection neuro-circuitries within the adolescent brain.


Assuntos
Alcoolismo/complicações , Encéfalo/fisiopatologia , Imagem por Ressonância Magnética/métodos , Abuso de Maconha/complicações , Adolescente , Alcoolismo/psicologia , Feminino , Humanos , Masculino , Abuso de Maconha/psicologia , Recompensa
15.
Neuroimage Clin ; 19: 782-792, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29988822

RESUMO

Alcohol and cannabis are two substances that are commonly abused by adolescents in the United States and which, when abused, are associated with negative medical and psychiatric outcomes across the lifespan. These negative psychiatric outcomes may reflect the detrimental impact of substance abuse on neural systems mediating emotion processing and executive attention. However, work indicative of this has mostly been conducted either in animal models or adults with Alcohol and/or Cannabis Use Disorder (AUD/CUD). Little work has been conducted in adolescent patients. In this study, we used the Affective Stroop task to examine the relationship in 82 adolescents between AUD and/or CUD symptom severity and the functional integrity of neural systems mediating emotional processing and executive attention. We found that AUD symptom severity was positively related to amygdala responsiveness to emotional stimuli and negatively related to responsiveness within regions implicated in executive attention and response control (i.e., dorsolateral prefrontal cortex, anterior cingulate cortex, precuneus) as a function of task performance. In contrast, CUD symptom severity was unrelated to amygdala responsiveness but positively related to responsiveness within regions including precuneus, posterior cingulate cortex, and inferior parietal lobule as a function of task performance. These data suggest differential impacts of alcohol and cannabis abuse on the adolescent brain.


Assuntos
Alcoolismo/diagnóstico por imagem , Atenção/fisiologia , Encéfalo/diagnóstico por imagem , Emoções/fisiologia , Função Executiva/fisiologia , Abuso de Maconha/diagnóstico por imagem , Rede Nervosa/diagnóstico por imagem , Adolescente , Alcoolismo/psicologia , Feminino , Humanos , Masculino , Abuso de Maconha/psicologia , Testes Neuropsicológicos , Índice de Gravidade de Doença
16.
Am J Psychiatry ; 174(2): 110-117, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-27631963

RESUMO

OBJECTIVE: Deficits in reinforcement-based decision making have been reported in generalized anxiety disorder. However, the pathophysiology of these deficits is largely unknown; published studies have mainly examined adolescents, and the integrity of core functional processes underpinning decision making remains undetermined. In particular, it is unclear whether the representation of reinforcement prediction error (PE) (the difference between received and expected reinforcement) is disrupted in generalized anxiety disorder. This study addresses these issues in adults with the disorder. METHOD: Forty-six unmedicated individuals with generalized anxiety disorder and 32 healthy comparison subjects group-matched on IQ, gender, and age performed a passive avoidance task while undergoing functional MRI. Data analyses were performed using a computational modeling approach. RESULTS: Behaviorally, individuals with generalized anxiety disorder showed impaired reinforcement-based decision making. Imaging results revealed that during feedback, individuals with generalized anxiety disorder relative to healthy subjects showed a reduced correlation between PE and activity within the ventromedial prefrontal cortex, ventral striatum, and other structures implicated in decision making. In addition, individuals with generalized anxiety disorder relative to healthy participants showed a reduced correlation between punishment PEs, but not reward PEs, and activity within the left and right lentiform nucleus/putamen. CONCLUSIONS: This is the first study to identify computational impairments during decision making in generalized anxiety disorder. PE signaling is significantly disrupted in individuals with the disorder and may lead to their decision-making deficits and excessive worry about everyday problems by disrupting the online updating ("reality check") of the current relationship between the expected values of current response options and the actual received rewards and punishments.


Assuntos
Transtornos de Ansiedade/fisiopatologia , Transtornos de Ansiedade/psicologia , Aprendizagem da Esquiva/fisiologia , Tomada de Decisões/fisiologia , Imagem por Ressonância Magnética , Córtex Pré-Frontal/fisiologia , Reforço Psicológico , Enquadramento Psicológico , Adolescente , Adulto , Transtornos de Ansiedade/diagnóstico , Feminino , Humanos , Aumento da Imagem , Masculino , Pessoa de Meia-Idade , Oxigênio/sangue , Modelagem Computacional Específica para o Paciente , Reconhecimento Visual de Modelos/fisiologia , Valores de Referência , Adulto Jovem
17.
Neurosci Biobehav Rev ; 71: 362-378, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27593443

RESUMO

Social anxiety disorder (SAD) is a disabling psychiatric disorder with a complex pathogenesis. Studies indicate a genetic component in the development of SAD, but the search for genetic mechanisms underlying this vulnerability is complicated. A focus on endophenotypes instead of the disorder itself may provide a fruitful path forward. Endophenotypes are measurable characteristics related to complex psychiatric disorders and reflective of genetically-based disease mechanisms, and could shed light on the ways by which genes contribute to the development of SAD. We review evidence for candidate MRI endophenotypes of SAD and discuss the extent to which they meet the criteria for an endophenotype, focussing on the amygdala, the medial prefrontal cortex, whole-brain functional connectivity and structural-anatomical changes. Strongest evidence is present for the primary endophenotype criterion of association between the candidate endophenotypes and SAD, while the other criteria, involving trait-stability, heritability and co-segregation of the endophenotype with the disorder within families, warrant further investigation. We highlight the potential of neuroimaging endophenotypes and stress the need for family studies into SAD endophenotypes.


Assuntos
Endofenótipos , Fobia Social , Encéfalo , Humanos , Imagem por Ressonância Magnética
18.
Psychiatry Res ; 237: 351-6, 2016 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-26822065

RESUMO

There is preliminary data indicating that patients with generalized anxiety disorder (GAD) show impairment on decision-making tasks requiring the appropriate representation of reinforcement value. The current study aimed to extend this literature using the passive avoidance (PA) learning task, where the participant has to learn to respond to stimuli that engender reward and avoid responding to stimuli that engender punishment. Six stimuli engendering reward and six engendering punishment are presented once per block for 10 blocks of trials. Thirty-nine medication-free patients with GAD and 29 age-, IQ and gender matched healthy comparison individuals performed the task. In addition, indexes of social functioning as assessed by the Global Assessment of Functioning (GAF) scale were obtained to allow for correlational analyzes of potential relations between cognitive and social impairments. The results revealed a Group-by-Error Type-by-Block interaction; patients with GAD committed significantly more commission (passive avoidance) errors than comparison individuals in the later blocks (blocks 7,8, and 9). In addition, the extent of impairment on these blocks was associated with their functional impairment as measured by the GAF scale. These results link GAD with anomalous decision-making and indicate that a potential problem in reinforcement representation may contribute to the severity of expression of their disorder.


Assuntos
Transtornos de Ansiedade/fisiopatologia , Transtornos Cognitivos/fisiopatologia , Tomada de Decisões/fisiologia , Reforço Psicológico , Adulto , Transtornos de Ansiedade/complicações , Aprendizagem da Esquiva , Transtornos Cognitivos/etiologia , Humanos , Pessoa de Meia-Idade , Punição , Recompensa
19.
Neuroimage ; 78: 103-10, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23567883

RESUMO

Optimistic bias (OB) is seen when individuals underestimate their probability of experiencing negative life events and overestimate their probability of experiencing positive life events. A reduced OB has been linked with increased depression symptoms. However, given the relevance of this information to mood and anxiety disorders, little is currently known regarding the neurobiology of OB. In the current study, we examine the neural basis of OB in healthy individuals (n=33) during probability estimation of future positive and negative events occurring to themselves relative to other, comparable individuals. In line with previous work, subjects showed significant OB; they considered themselves significantly more likely to experience future positive and significantly less likely to experience future negative events relative to comparable others. Positive, relative to negative events, un-modulated by subjects' probability estimates, were associated with significantly greater activity within the ventromedial prefrontal cortex (vmPFC) and posterior cingulate cortex (PCC). Moreover, responses within both regions to positive events negatively related to the healthy subjects' self reports of depression symptoms. However, there was no significant modulation of activity in either region by the subject's OB, objectified as the level to which they thought the event was more likely [positive events] or less likely [negative events] to occur to them relative to comparable others. In contrast, activity within the rostral anterior cingulate cortex (rACC) was positively modulated by OB for positive events and activity within the anterior insula and dorsomedial prefrontal cortex (dmPFC) was negatively modulated by OB for negative events. However, there was no significant relationship between responsiveness within these regions and self reports of depression symptoms. The data are discussed with reference to current models of vmPFC, rACC and anterior insula functioning.


Assuntos
Mapeamento Encefálico , Giro do Cíngulo/fisiologia , Personalidade/fisiologia , Córtex Pré-Frontal/fisiologia , Adulto , Viés , Depressão/fisiopatologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Adulto Jovem
20.
Front Hum Neurosci ; 7: 46, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23450237

RESUMO

Self-referential processing is defined as the process by which a person becomes aware that specific contents are related to his or her own self. Cortical midline structures (CMS), such as dorsal and medial prefrontal cortex, and regions such as inferior frontal cortex, insula, and temporal pole have been implicated in self-referential processing. However, the specific contribution of each of these areas is still largely unknown. More particularly, not many studies have examined the influence of valence and decision making difficulty on regions involved in self-referential processing. In this study, participants evaluated how well personality traits, differing in valence and decision difficulty, described themselves or the current US President. In line with predictions, ventral, rostral, and dorsal parts of medial prefrontal cortex showed greater activity when participants judged traits about themselves relative to judging traits about the current US President. However, none of these regions showed significant modulation by trait valence. Increasing trait decision difficulty was associated with increased activity within dorsal medial prefrontal cortex and bilateral anterior insula. However, there was very minimal overlap (6/119 voxels, i.e., 5%) of the regions of dorsal medial prefrontal cortex implicated in self-referential processing and those implicated in trait decision difficulty. The results are interpreted within current accounts of self-referential processing.

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