Faculty Bibliography

Learning about potential threats is critical for survival. Learned fear responses are acquired either through direct experiences or indirectly through social transmission. Social fear learning (SFL), also known as vicarious fear learning, is a paradigm successfully used for studying the transmission of threat information between individuals. Animal and human studies have begun to elucidate the behavioral, neural and molecular mechanisms of SFL. Recent research suggests that social learning mechanisms underlie a wide range of adaptive and maladaptive phenomena, from supporting flexible avoidance in dynamic environments to intergenerational transmission of trauma and anxiety disorders. This review discusses recent advances in SFL studies and their implications for basic, social and clinical sciences.

Advanced paternal age (APA) at conception has been associated with negative outcomes in offspring, raising concerns about increasing age at fatherhood. Evidence from evolutionary and psychological research, however, suggests possible link between APA and a phenotypic advantage. We defined such advantage as educational success, which is positively associated with future socioeconomic status. We hypothesised that high IQ, strong focus on the subject of interest and little concern about 'fitting in' will be associated with such success. Although these traits are continuously distributed in the population, they cluster together in so-called 'geeks'. We used these measures to compute a 'geek index' (GI), and showed it to be strongly predictive of future academic attainment, beyond the independent contribution of the individual traits. GI was associated with paternal age in male offspring only, and mediated the positive effects of APA on education outcomes, in a similar sexually dimorphic manner. The association between paternal age and GI was partly mediated by genetic factors not correlated with age at fatherhood, suggesting contribution of de novo factors to the 'geeky' phenotype. Our study sheds new light on the multifaceted nature of the APA effects and explores the intricate links between APA, autism and talent.

When animals and their offspring are threatened, parents switch from self-defense to offspring protection. How self-defense is suppressed remains elusive. We postulated that suppression of the self-defense response, freezing, is gated via oxytocin acting in the centro-lateral amygdala (CeL). We found that rat dams conditioned to fear an odor, froze when tested alone, whereas if pups were present, they remained in close contact with them or targeted the threat. Furthermore, blocking oxytocin signaling in the CeL prevented the suppression of maternal freezing. Finally, pups exposed to the odor in the presence of the conditioned dam later froze when re-exposed alone. However, if oxytocin signaling in the dam had been blocked, pups failed to learn. This study provides a functional role for the well-described action of oxytocin in the central amygdala, and demonstrates that self-defense suppression allows for active pup protection and mother-pup interactions crucial for pup threat learning.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social deficits and repetitive behaviors that typically emerge by 24 months of age. To develop effective early interventions that can potentially ameliorate the defining deficits of ASD and improve long-term outcomes, early detection is essential. Using prospective neuroimaging of 59 6-month-old infants with a high familial risk for ASD, we show that functional connectivity magnetic resonance imaging correctly identified which individual children would receive a research clinical best-estimate diagnosis of ASD at 24 months of age. Functional brain connections were defined in 6-month-old infants that correlated with 24-month scores on measures of social behavior, language, motor development, and repetitive behavior, which are all features common to the diagnosis of ASD. A fully cross-validated machine learning algorithm applied at age 6 months had a positive predictive value of 100% [95% confidence interval (CI), 62.9 to 100], correctly predicting 9 of 11 infants who received a diagnosis of ASD at 24 months (sensitivity, 81.8%; 95% CI, 47.8 to 96.8). All 48 6-month-old infants who were not diagnosed with ASD were correctly classified [specificity, 100% (95% CI, 90.8 to 100); negative predictive value, 96.0% (95% CI, 85.1 to 99.3)]. These findings have clinical implications for early risk assessment and the feasibility of developing early preventative interventions for ASD.

Controversy exists regarding whether gastrointestinal (GI) issues play a role in the symptomatology of autism spectrum disorder (ASD). While some studies have found GI problems to be more prevalent in individuals with ASD, others have reported no such difference. Studies looking at the relationship between GI issues and ASD symptom severity have also had mixed results. The current study examined 112 participants between the age of 17 to 37 months. Participants comprised four groups of 28 children: an ASD and no GI issues group, an ASD with GI problems group, an atypical development and no GI issues group, and an atypical development with GI issues group. The results of the current study suggest that although the prevalence of GI symptoms was higher in participants with ASD than those without, this difference was not significant. The study also found that GI issues were not related to ASD symptom severity or developmental functioning.

OBJECTIVES:Epidemiological studies suggest that cyclothymic disorder is the most prevalent subtype of bipolar disorder (BD). However, it is rarely diagnosed, especially in youth. This may be because it can be difficult to ascertain whether a youth meets diagnostic criteria. Clearer, easy-to-apply criteria could reduce misdiagnosis. The objective oftable this study was to determine whether proposed research diagnostic criteria for cyclothymic disorder (RDCyc), based on DSM-5 criteria, could be quantified and validated in youth. METHODS:Participants from the Longitudinal Assessment of Manic Symptoms (LAMS) study were recruited based on symptoms of mania and followed prospectively. RDCyc criteria were: 1) At least one core symptom each of mania and depression; 2) one additional symptom of mania and of depression; 3) persistence over two consecutive six-month periods, and 4) impairment. Exclusionary criteria were having a [hypo]manic or depressive episode. Outcomes at the two-year follow-up were compared between RDCyc youth and other diagnostic groups (BD I/II, BD NOS/non-RDCyc cyclothymic disorder, disruptive behavior disorders [DBD], depression). RESULTS:Thirty-seven youth met RDCyc criteria. There were no consistent differences between the RDCyc youth and youth with other BD subtypes (ps=0.001-0.960, with all-but-one p value >0.02). RDCyc youth had higher depression (p<0.0005) and mania scores (p=0.001), lower functioning (p=0.012), and higher suicide risk than DBD youth (p=0.001). They had higher mania scores than depressed youth (p.018). LIMITATIONS:The majority of youth in the sample were recruited due to elevated symptoms of mania, which may limit the generalizability of the results. Youth were followed for two years, which may not be long enough to determine whether or not they will eventually develop a manic or depressive episode. CONCLUSIONS:Applying RDCyc criteria identified youth who were similar to others with BD and were more impaired than those with DBD. Using these criteria could reduce misdiagnosis and increase our understanding of this prevalent, but largely ignored, diagnosis.

Since the Third Edition, the Diagnostic and Statistical Manual of Mental Disorders (DSM) has increasingly incorporated developmentally informed criteria for posttraumatic stress disorder (PTSD) because of recognition that children and adolescents can manifest PTSD differently from adults. The most recent edition, DSM-5, among other changes, has introduced a developmental subtype for children six years of age or younger. As pediatric PTSD features very prominently in both civil and criminal proceedings, it is vital that the expert witness be familiar with the updated criteria and know how to interview traumatized youth appropriately in the forensic setting. In this review, we discuss the importance of the evolution of PTSD from past DSM editions to the current one, and the implications of using the new diagnostic criteria and current conceptual models in the forensic evaluation of pediatric PTSD.

BACKGROUND AND OBJECTIVES: Understanding of parent anxiety and its effect on infant postoperative pain is limited. We sought to identify psychological factors associated with preoperative anxiety for parents of infants and toddlers undergoing elective surgery and to determine whether parent anxiety is associated with child postoperative pain. METHODS: This was a prospective cohort study of consecutively eligible patients aged