The genetic and environmental structure of fear and anxiety in juvenile twins

Using Decision Trees to Examine Environmental and Behavioural Factors Associated with Youth Anxiety, Depression, and Flourishing

Modifiable environmental and behavioural factors influence youth mental health; however, past studies have primarily used regression models that quantify population average effects. Decision trees are an analytic technique that examine complex relationships between factors and identify high-risk subgroups to whom intervention measures can be targeted. This study used decision trees to examine associations of various risk factors with youth anxiety, depression, and flourishing. Data were collected from 74,501 students across Canadian high schools participating in the 2018-2019 COMPASS Study. Students completed a questionnaire including validated mental health scales and 23 covariates. Decision trees were grown to identify key factors and subgroups for anxiety, depression, and flourishing outcomes. Females lacking both happy home life and sense of connection to school were at greatest risk for higher anxiety and depression levels. In contrast with previous literature, behavioural factors such as diet, movement and substance use did not emerge as differentiators. This study highlights the influence of home and school environments on youth mental health using a novel decision tree analysis. While having a happy home life is most important in protecting against youth anxiety and depression, a sense of connection to school may mitigate the negative influence of a poor home environment.

Girls' Stuff? Maternal Gender Stereotypes and Their Daughters' Fear

One of the most robust findings in psychopathology is the fact that specific phobias are more prevalent in women than in men. Although there are several theoretical accounts for biological and social contributions to this gender difference, empirical data are surprisingly limited. Interestingly, there is evidence that individuals with stereotypical feminine characteristics are more fearful than those with stereotypical masculine characteristics; this is beyond biological sex. Because gender role stereotypes are reinforced by parental behavior, we aimed to examine the relationship of maternal gender stereotypes and children’s fear. Dyads of 38 mothers and their daughters (between ages 6 and 10) were included. We assessed maternal implicit and explicit gender stereotypes as well as their daughters’ self-reported general fearfulness, specific fear of snakes, and approach behavior toward a living snake. First, mothers’ fear of snakes significantly correlated with their daughters’ fear of snakes. Second, mothers’ gender stereotypes significantly correlated with their daughters’ self-reported fear. Specifically, maternal implicit gender stereotypes were associated with daughters’ fear of snakes and fear ratings in response to the snake. Moreover, in children, self-reported fear correlated with avoidance of the fear-relevant animal. Together, these results provide first evidence for a potential role of parental gender stereotypes in the development and maintenance of fear in their offspring.

Transcriptional Profiling of Primate Central Nucleus of the Amygdala Neurons to Understand the Molecular Underpinnings of Early-Life Anxious Temperament

BACKGROUND

Children exhibiting extreme anxious temperament (AT) are at an increased risk for developing anxiety and depression. Our previous mechanistic and neuroimaging work in young rhesus monkeys linked the central nucleus of the amygdala to AT and its underlying neural circuit.

METHODS

Here, we used laser capture microscopy and RNA sequencing in 47 young rhesus monkeys to investigate AT's molecular underpinnings by focusing on neurons from the lateral division of the central nucleus of the amygdala (CeL). RNA sequencing identified numerous AT-related CeL transcripts, and we used immunofluorescence (n = 3) and tract-tracing (n = 2) methods in a different sample of monkeys to examine the expression, distribution, and projection pattern of neurons expressing one of these transcripts.

RESULTS

We found 555 AT-related transcripts, 14 of which were confirmed with high statistical confidence (false discovery rate < .10), including protein kinase C delta (PKCδ), a CeL microcircuit cell marker implicated in rodent threat processing. We characterized PKCδ neurons in the rhesus CeL, compared its distribution with that of the mouse, and demonstrated that a subset of these neurons project to the laterodorsal bed nucleus of the stria terminalis.

CONCLUSIONS

These findings demonstrate that CeL PKCδ is associated with primate anxiety, provides evidence of a CeL to laterodorsal bed nucleus of the stria terminalis circuit that may be relevant to understanding human anxiety, and points to specific molecules within this circuit that could serve as potential treatment targets for anxiety disorders.

The influence of subcortical shortcuts on disordered sensory and cognitive processing

The very earliest stages of sensory processing have the potential to alter how we perceive and respond to our environment. These initial processing circuits can incorporate subcortical regions, such as the thalamus and brainstem nuclei, which mediate complex interactions with the brain's cortical processing hierarchy. These subcortical pathways, many of which we share with other animals, are not merely vestigial but appear to function as 'shortcuts' that ensure processing efficiency and preservation of vital life-preserving functions, such as harm avoidance, adaptive social interactions and efficient decision-making. Here, we propose that functional interactions between these higher-order and lower-order brain areas contribute to atypical sensory and cognitive processing that characterizes numerous neuropsychiatric disorders.

The Mid-Atlantic Twin Registry of Virginia Commonwealth University

The Mid-Atlantic Twin Registry (MATR) is a population-based registry of more than 60,000 twins primarily born or living in Virginia, North Carolina and South Carolina. Researchers may utilize the MATR for administration of research services, including study recruitment, data or sample (e.g., DNA) collection, archival dataset creation, as well as data collection through mailed, phone or online surveys. In addition, the MATR houses the MATR Repository, with over 1700 DNA samples primarily from whole blood available for researchers interested in DNA genotyping. For over 40 years MATR twins have participated in research studies with investigators from a range of scientific disciplines and institutions. These studies, which have resulted in numerous publications, explored diverse topics, including substance use, smoking behaviors, developmental psychopathology, bullying, children's health, cardiovascular disease, cancer, the human microbiome, epigenetics of aging, children of twins and sleep homeostasis. Researchers interested in utilizing twins are encouraged to contact the MATR to discuss potential research opportunities.