635. THE NEUROBIOLOGICAL FOUNDATION FOR PHYSICAL EXERCISE RECOMMENDATIONS IN REDUCING SYMPTOMS OF ADHD

Abstract Background The neurobiology of ADHD (Attention Deficit Hyperactivity Disorder) is complex and involves various dysfunctions in the brain and neurotransmitter systems. Both pharmacological and non-pharmacological therapies aim to address these issues, alleviating symptoms and improving functioning. Physical activity as a part of therapy may be particularly beneficial for individuals with ADHD, as scientific studies have shown its positive impact on the prevention and treatment of often co-occurring mental disorders. Additionally, research suggests that physical exercise can help reduce the severity of ADHD symptoms, including excessive motor activity, impulsivity, and distractibility. Aims & Objectives The study aims to explore the biological basis for the possible beneficial effects of physical exercise on ADHD and outline further steps in translational research. Research objectives are as follows: 1) discuss if and how physical exercise can positively influence ADHD symptoms, and 2) investigate biological mechanisms underlying the relationship between physical exercise and domains of cognitive functions often impaired in ADHD. Method A narrative review of the literature published in English in the PubMed and EMBASE databases until February 14, 2025, was conducted. Results ADHD is linked to abnormalities in several neurotransmitter systems, including dopamine, noradrenaline, serotonin, glutamate, and GABA. Neuroimaging studies have shown differences in brain structure and function in individuals with ADHD, particularly in areas such as the hemifunctional nucleus, amygdala, caudate nucleus, hippocampus, and shell, as well as in the cerebral cortex—especially in the frontal, cingulate, and temporal regions. ADHD is associated with delayed cerebral cortex maturation, particularly in the frontal and parietal areas, which are crucial for executive functions. Research using diffusion tensor imaging (DTI) suggests that ADHD is associated with microstructural changes in white matter, particularly in frontal-striatal circuits and connections between the brain's hemispheres. Additionally, epigenetic studies have identified alterations in DNA methylation in individuals with ADHD. The mechanisms underlying the effectiveness of exercise in the context of ADHD are complex and include neurobiological, psychosocial, and behavioral aspects. Exercise stimulates adaptive neuroplasticity and increases brain-derived neurotrophic factor (BDNF) levels, crucial for learning, memory, and brain health. Exercise activates autophagy, which promotes cellular homeostasis and neuroplasticity. In addition, a study from 2023 suggests that irisin (released by physical activity) has been shown to affect neuroplasticity by upregulating BDNF and activating autophagy. FMRI studies indicate changes in brain activity due to exercise, particularly in the prefrontal cortex, parietal areas, and basal nuclei, which may correlate with improvements in ADHD symptoms. The relationship between exercise intensity and cognitive function indicates an optimal arousal level for peak performance. Moderate exercise enhances arousal and improves cognitive function, while high intensity may hinder it. The Reticular-Activating Hypofrontality (RAH) model suggests that exercise engages arousal mechanisms associated with neurotransmitter systems to facilitate processing cognitive-emotional information. Discussion & Conclusions Physical exercise may alleviate ADHD symptoms by enhancing memory, cognitive functions, and neuroprotection through various mechanisms of action. Further research is needed on the optimal duration, intensity, and types of exercise, but it should currently be used as a supplement to standard treatments.