Investigating the causal impact of different types of physical activity on psychiatric disorders across life stages: A Mendelian randomization study

Background: Psychiatric disorders, including attention-deficit hyperactivity disorder (ADHD), depression, anxiety disorders, and dementia, manifest differently across life stages, impacting cognitive, emotional, and behavioral health. Understanding the causal relationships between various types of physical activity and these disorders is crucial for developing targeted interventions. Methods: The summary level data from GWAS was utilized to conduct a two-sample Mendelian Randomization (MR) analysis. We assessed the potential causal relationships between different types of physical activity including light do it yourself (DIY) activities, heavy DIY activities, strenuous sports, and aerobic exercises/other exercises and the prevalence of psychiatric disorders (ADHD, depression, anxiety disorders, and dementia) across different life stages. Results: The MR analysis showed no causal relationship between light DIY activities and any of the psychiatric disorders studied. Heavy DIY activities showed a significant negative association with anxiety disorders but no links with ADHD, depression, or dementia. Strenuous sports did not demonstrate any causal relationship with the psychiatric disorders examined. Aerobic exercises were notably correlated with a reduced risk of depression, although no significant associations were found with ADHD, anxiety disorders, or dementia. Conclusions: The findings indicate that heavy DIY activities might contribute to reducing anxiety disorders, while aerobic exercises potentially lower the risk of depression. These results emphasize the potential benefits of promoting specific types of physical activity to improve mental health outcomes across different life stages. Future research could further investigate the mechanisms underlying these relationships and consider diverse populations and objective measures of physical activity.