Abstract
Attention-deficit/hyperactivity disorder (ADHD) is a common psychiatric condition among children and adolescents, often associated with a high risk of psychiatric comorbidities. Currently, ADHD diagnosis relies exclusively on clinical presentation and patient history, underscoring the need for clinically relevant, reliable, and objective biomarkers. Such biomarkers may enable earlier diagnosis and lead to improved treatment outcomes. Our research team has focused on identifying potential biomarkers for ADHD by investigating its possible pathomechanisms, with consideration of the aforementioned criteria. Given the significant sex-related differences in ADHD prevalence (male predominance) and the age-related variability in its symptomatology, we explored the role of neuroendocrine systems in ADHD. Specifically, we examined the epigenetic regulation mechanism involved in ADHD pathogenesis and developed a diagnostic model based on peripheral microRNA. Additionally, we investigated the role of microbiota dysbiosis in the pathophysiology of ADHD and provided novel insights into its management. This paper presents a summary of our findings on potential biomarkers for ADHD. By analyzing blood, salivary, and fecal samples, we identified several promising biomarkers that may serve as objective parameters for improving the diagnostic accuracy for ADHD. Further research involving larger cohort studies is required to confirm the reliability of these biomarkers.