Sex-specific vulnerability to depressive symptoms across adolescence and during the COVID-19 pandemic: The role of the cingulum bundle

The default mode network is associated with changes in internalizing and externalizing problems differently in adolescent boys and girls

Internalizing and externalizing problems that emerge during adolescence differentially increase boys' and girls' risk for developing psychiatric disorders. It is not clear, however, whether there are sex differences in the intrinsic functional architecture of the brain that underlie changes in the severity of internalizing and externalizing problems in adolescents. Using resting-state fMRI data and self-reports of behavioral problems obtained from 128 adolescents (73 females; 9-14 years old) at two timepoints, we conducted multivoxel pattern analysis to identify resting-state functional connectivity markers at baseline that predict changes in the severity of internalizing and externalizing problems in boys and girls 2 years later. We found sex-differentiated involvement of the default mode network in changes in internalizing and externalizing problems. Whereas changes in internalizing problems were associated with the dorsal medial subsystem in boys and with the medial temporal subsystem in girls, changes in externalizing problems were predicted by hyperconnectivity between core nodes of the DMN and frontoparietal network in boys and hypoconnectivity between the DMN and affective networks in girls. Our results suggest that different neural mechanisms predict changes in internalizing and externalizing problems in adolescent boys and girls and offer insights concerning mechanisms that underlie sex differences in the expression of psychopathology in adolescence.

Exploring sex differences in trajectories of pubertal development and mental health following early adversity

Despite evidence that early life adversity (ELA) affects mental health in adolescence, we know little about sex differences in how distinct dimensions of adversity affect development and their corresponding effects on mental health. In this three-wave longitudinal study, 209 participants (118 females; ages 9-13 years at baseline) provided objective (salivary hormones, BMI, age of menarche) and subjective (perceived gonadal and adrenal status) measures of puberty and physical development, and reported on levels of internalizing and externalizing symptoms at all timepoints. Participants also reported lifetime exposure to three distinct types of ELA: deprivation, threat, and unpredictability. Using generalized additive mixed models, we tested within each sex whether dimensions of adversity were associated with longitudinal changes in measures of pubertal and physical development, and whether these indices of development were associated with trajectories of internalizing and externalizing symptoms. In females, experiences of threat and unpredictability were significantly associated with earlier pubertal timing (e.g., age of menarche) whereas experiences of deprivation were associated with steeper increases in BMI; further, faster pubertal tempo (i.e., steeper increases in pubertal stage) was associated with increases in internalizing and externalizing symptoms. In males, however, ELA was not associated with any measures of pubertal or physical development or with symptoms. Together, our results suggest that adverse experiences during early life have sex-selective consequences for pubertal and physical maturation and mental health trajectories in ways that may elucidate why females are at higher risk for mental health difficulties during puberty, particularly following exposure to unpredictable and threatening experiences of adversity.

Brain-based Sex Differences in Depression: A Systematic Review of Neuroimaging Studies

Major depressive disorder (MDD) is a common psychiatric illness with a wide range of symptoms such as mood decline, loss of interest, and feelings of guilt and worthlessness. Women develop depression more often than men, and the diagnostic criteria for depression mainly rely on female patients' symptoms. By contrast, male depression usually manifests as anger attacks, aggression, substance use, and risk-taking behaviors. Various studies have focused on the neuroimaging findings in psychiatric disorders for a better understanding of their underlying mechanisms. With this review, we aimed to summarize the existing literature on the neuroimaging findings in depression, separated by male and female subjects. A search was conducted on PubMed and Scopus for magnetic resonance imaging (MRI), functional MRI (fMRI), and diffusion tensor imaging (DTI) studies of depression. After screening the search results, 15 MRI, 12 fMRI, and 4 DTI studies were included. Sex differences were mainly reflected in the following regions: 1) total brain, hippocampus, amygdala, habenula, anterior cingulate cortex, and corpus callosum volumes, 2) frontal and temporal gyri functions, along with functions of the caudate nucleus and prefrontal cortex, and 3) frontal fasciculi and frontal projections of corpus callosum microstructural alterations. Our review faces limitations such as small sample sizes and heterogeneity in populations and modalities. But in conclusion, it reflects the possible roles of sex-based hormonal and social factors in the depression pathophysiology.

Early life stress, sleep disturbances, and depressive symptoms during adolescence: The role of the cingulum bundle

Adolescence is often characterized by sleep disturbances that can affect the development of white matter tracts implicated in affective and cognitive regulation, including the cingulate portion of the cingulum bundle (CGC) and the uncinate fasciculus (UF). These effects may be exacerbated in adolescents exposed to early life adversity (ELA). We examined the longitudinal relations between sleep problems and CGC and UF microstructure during adolescence and their relation to depressive symptoms as a function of exposure to ELA. We assessed self-reported sleep disturbances and depressive symptoms and acquired diffusion-weighted MRI scans twice: in early adolescence (9-13 years) and four years later (13-17 years) (N = 72 complete cases). Independent of ELA, higher initial levels and increases in sleep problems were related to increases in depressive symptoms. Further, increases in right CGC fractional anisotropy (FA) mediated the association between sleep problems and depressive symptoms for youth who experienced lower, but not higher, levels of ELA. In youth with higher ELA, higher initial levels of and steeper decreases in sleep problems were associated with greater decreases in right UF FA, but were unrelated to depressive symptoms. Our findings highlight the importance of sleep quality in shaping fronto-cingulate-limbic tract development and depressive symptoms during adolescence.

A review of brain regions and associated post-concussion symptoms

The human brain is an exceptionally complex organ that is comprised of billions of neurons. Therefore, when a traumatic event such as a concussion occurs, somatic, cognitive, behavioral, and sleep impairments are the common outcome. Each concussion is unique in the sense that the magnitude of biomechanical forces and the direction, rotation, and source of those forces are different for each concussive event. This helps to explain the unpredictable nature of post-concussion symptoms that can arise and resolve. The purpose of this narrative review is to connect the anatomical location, healthy function, and associated post-concussion symptoms of some major cerebral gray and white matter brain regions and the cerebellum. As a non-exhaustive description of post-concussion symptoms nor comprehensive inclusion of all brain regions, we have aimed to amalgamate the research performed for specific brain regions into a single article to clarify and enhance clinical and research concussion assessment. The current status of concussion diagnosis is highly subjective and primarily based on self-report of symptoms, so this review may be able to provide a connection between brain anatomy and the clinical presentation of concussions to enhance medical imaging assessments. By explaining anatomical relevance in terms of clinical concussion symptom presentation, an increased understanding of concussions may also be achieved to improve concussion recognition and diagnosis.

Pre-pandemic brain structure and function and adolescent psychopathology during the COVID-19 pandemic

The COVID-19 pandemic has presented unprecedented challenges for youths and families, dramatically increasing exposure to stressors and stress-related psychopathology. Increasing work has leveraged pre-pandemic neuroimaging data to predict adolescent psychopathology and stress responses during the pandemic, with a particular focus on internalizing symptoms. We review this recent literature on pre-pandemic brain structure and function and adolescent internalizing psychopathology during the pandemic. At present, existing studies have not consistently identified specific alterations in brain structure and function that predict anxiety or depressive symptoms during the pandemic. In contrast, exposure to stress and adversity before and during the pandemic as well as access to peer and family support have emerged as consistent and reliable predictors of youth mental health during the pandemic.

Adolescent non-suicidal self-injury during the COVID-19 pandemic: A prospective longitudinal study of biological predictors of maladaptive emotion regulation

BACKGROUND

Non-suicidal self-injury (NSSI) in adolescence is thought to stem from interactions between vulnerability in developing biological systems and experience of stressors. The current study assesses whether multiple levels of the stress system's response to threat could prospectively predict NSSI engagement during the COVID-19 pandemic, a shared, time-locked stressor.

METHODS

Participants were 64 female adolescents (ages 12-16) from community and clinical settings who were oversampled for NSSI histories. Prior to the onset of the COVID-19 pandemic, adolescents completed a protocol that measured hypothalamic-pituitary-adrenal axis response to a social stressor (via salivary cortisol), amygdala volume, amygdala emotion-evoked activation, and frontolimbic resting-state functional connectivity. During early months of the pandemic (Summer 2020), measures of NSSI behavior (Inventory of Statements About Self-Injury), emotion regulation difficulties (Difficulties in Emotion Regulation Scale), perceived stress (Perceived Stress Scale), and pandemic-related stressors (Epidemic Pandemic Impacts Inventory) were collected. Multinomial logistic regression was used to assess if pre-pandemic biomarkers predicted mid-pandemic NSSI engagement: persistence of NSSI (Persist; N = 21), cessation of NSSI (Desist; N = 26), and no history of NSSI (Never; N = 17). Linear regressions explored if pre-pandemic biomarkers predicted mid-pandemic difficulties in emotion regulation and perceived stress.

RESULTS

Higher pre-pandemic overall cortisol response to stress and amygdala emotion-evoked activation characterized adolescents who persisted in NSSI, compared to those who desisted. These findings remained significant when controlling for pandemic related stressors. Lower prepandemic cortisol reactivity predicted more difficulties in emotion regulation during the pandemic. This finding did not remain significant after controlling for pandemic related stressors.

CONCLUSIONS

Findings suggest that patterns in key biological threat response systems may confer vulnerability for risk outcomes including NSSI engagement in adolescent females in the context of a shared, novel, naturally-occurring stressor. The results point to the importance of multi-level, longitudinal approaches for understanding the interface between developing neurobiological systems and experiential stress in at-risk adolescents. Identified patterns give insight into potential risk assessment strategies based on an understanding of the multi-level threat response.

Effects of the COVID-19 Pandemic on Mental Health and Brain Maturation in Adolescents: Implications for Analyzing Longitudinal Data

Background

The COVID-19 pandemic has caused significant stress and disruption for young people, likely leading to alterations in their mental health and neurodevelopment. In this context, it is not clear whether youth who lived through the pandemic and its shutdowns are comparable psychobiologically to their age- and sex-matched peers assessed before the pandemic. This question is particularly important for researchers who are analyzing longitudinal data that span the pandemic.

Methods

In this study we compared carefully matched youth assessed before the pandemic (n=81) and after the pandemic-related shutdowns ended (n=82).

Results

We found that youth assessed after the pandemic shutdowns had more severe internalizing mental health problems, reduced cortical thickness, larger hippocampal and amygdala volume, and more advanced brain age.

Conclusions

Thus, not only does the COVID-19 pandemic appear to have led to poorer mental health and accelerated brain aging in adolescents, but it also poses significant challenges to researchers analyzing data from longitudinal studies of normative development that were interrupted by the pandemic.

Earlier Bedtime and Effective Coping Skills Predict a Return to Low-Risk of Depression in Young Adults during the COVID-19 Pandemic

To determine the persistent effects of the pandemic on mental health in young adults, we categorized depressive symptom trajectories and sought factors that promoted a reduction in depressive symptoms in high-risk individuals. Specifically, longitudinal analysis investigated changes in the risk for depression before and during the pandemic until December 2021 in 399 young adults (57% female; age range: 22.8 ± 2.6 years) in the United States (U.S.) participating in the National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA) study. The Center for Epidemiologic Studies Depression Scale (CES-D-10) was administered multiple times before and during the pandemic. A score ≥10 identified individuals at high-risk for depression. Self-reported sleep behavior, substance use, and coping skills at the start of the pandemic were assessed as predictors for returning to low-risk levels while controlling for demographic factors. The analysis identified four trajectory groups regarding depression risk, with 38% being at low-risk pre-pandemic through 2021, 14% showing persistent high-risk pre-pandemic through 2021, and the remainder converting to high-risk either in June 2020 (30%) or later (18%). Of those who became high-risk in June 2020, 51% were no longer at high-risk in 2021. Logistic regression revealed that earlier bedtime and, for the older participants (mid to late twenties), better coping skills were associated with this declining risk. Results indicate divergence in trajectories of depressive symptoms, with a considerable number of young adults developing persistent depressive symptoms. Healthy sleep behavior and specific coping skills have the potential to promote remittance from depressive symptoms in the context of the pandemic.