Physical Activity Participation among Children and Youth with Mental Health Symptoms: Clinician Perspectives.

BACKGROUND/OBJECTIVES: Physical activity supports mental health and well-being in children and youth. However, there are significant barriers to physical activity participation among individuals impacted by mental health disorders. This study investigates these barriers through the perspective of mental health clinicians who support children and youth. METHODS: Fourteen mental health clinicians, including registered professional psychologists, psychotherapists, and social workers, were interviewed in a semi-structured format. Qualitative content analysis was performed to identify key themes, including both barriers and facilitators to physical activity. RESULTS: Content analysis revealed that clinicians perceive both internal and external barriers and facilitators to their clients' participation in physical activity. Barriers included intrapersonal factors, such as the presence of depression, anxiety, or eating disorder symptoms; lack of motivation; and negative self-talk, as well as factors related to the influence of caregivers, financial limitations, screen time use, environmental and cultural factors, and lack of time. Facilitators included enjoyment of physical activity, knowledge about the benefits of physical activity, and caregiver participation. CONCLUSIONS: Mental health clinicians demonstrated clear knowledge about the barriers to and facilitators of their clients' participation in physical activity. These findings provide valuable insights that can be used to support children and youth experiencing mental health difficulty to access the beneficial effects of physical activity.

Alzheimer's disease associated isoforms of human CD33 distinctively modulate microglial cell responses in 5XFAD mice.

Microglia play diverse pathophysiological roles in Alzheimer's disease (AD), with genetic susceptibility factors skewing microglial cell function to influence AD risk. CD33 is an immunomodulatory receptor associated with AD susceptibility through a single nucleotide polymorphism that modulates mRNA splicing, skewing protein expression from a long protein isoform (CD33M) to a short isoform (CD33m). Understanding how human CD33 isoforms differentially impact microglial cell function in vivo has been challenging due to functional divergence of CD33 between mice and humans. We address this challenge by studying transgenic mice expressing either of the human CD33 isoforms crossed with the 5XFAD mouse model of amyloidosis and find that human CD33 isoforms have opposing effects on the response of microglia to amyloid-ß (Aß) deposition. Mice expressing CD33M have increased Aß levels, more diffuse plaques, fewer disease-associated microglia, and more dystrophic neurites compared to 5XFAD control mice. Conversely, CD33m promotes plaque compaction and microglia-plaque contacts, and minimizes neuritic plaque pathology, highlighting an AD protective role for this isoform. Protective phenotypes driven by CD33m are detected at an earlier timepoint compared to the more aggressive pathology in CD33M mice that appears at a later timepoint, suggesting that CD33m has a more prominent impact on microglia cell function at earlier stages of disease progression. In addition to divergent roles in modulating phagocytosis, scRNAseq and proteomics analyses demonstrate that CD33m+ microglia upregulate nestin, an intermediate filament involved in cell migration, at plaque contact sites. Overall, our work provides new functional insights into how CD33, as a top genetic susceptibility factor for AD, modulates microglial cell function.

Physical Activity in High School Classrooms: A Promising Avenue for Future Research.

Adolescence represents a sensitive period whereby lifestyle factors such as physical activity can have profound, long-lasting effects on development and later life habits. However, adolescence constitutes a period of frequent sedentary behaviour. Among children, integrating physical activity into elementary school classrooms has been shown to reduce sedentary behaviour and improve academic achievement and overall physical and mental health. However, this promising area of research has not extended to adolescents and high school classrooms. In this paper, we describe the benefits of conducting research on the impact of physically active high school classrooms, and highlight the challenges and potential misconceptions associated with research in this field. Specifically, we review research on the role of physical activity in adolescent development, the benefits of classroom-based physical activity for children, and discuss the factors that may have led researchers to focus on classroom-based physical activity primarily for children, despite the potentially similar benefits for adolescents.