High Mobility Group Box 1 Protein as a Biomarker in Adult Attention Deficit Hyperactivity Disorder

Attention deficit hyperactivity disorder (ADHD), while representing the most frequently diagnosed and treated condition in child and adolescent psychiatry, continues to be underrecognized and inadequately managed in adult populations. Numerous studies have explored how ADHD may be connected to the immune system and inflammatory processes. These studies have focused particularly on ADHD, stress, anxiety and immune dysregulation. High Mobility Group Box 1 (HMGB1), a nuclear transcription factor and a late-phase mediator of inflammation, has been found to be elevated in various neuropsychiatric conditions. This study aimed to elucidate the potential contribution of inflammatory mechanisms to the pathophysiology of ADHD by quantifying HMGB1 levels.

43 ADHD patients and 42 controls with an age between 18-65 years were enrolled. Patients with any acute or chronic psychiatric disease, chronic inflammatory or autoimmune disease, substance addiction, malignancy, severe systemic disease, schizophrenia, mental retardation, a history of surgery or head trauma in the last 6 months and who were on vitamin or fish oil supplements or steroids were excluded. Blood samples were obtained and HMGB1 was measured with Enzyme-Linked Immuno Sorbent Assay method.

The two groups exhibited comparable sociodemographic characteristics. HMGB1 levels were significantly higher in ADHD group than controls (967.5 ± 462.0 ng/mL vs 693.4 ± 366.9 ng/mL, p = 0.003).

In our study, the finding that HMGB1 serum levels were higher in adult ADHD patients compared to healthy controls supports the hypothesis that chronic low-grade inflammation, which is both driven and detected by HMGB1, may be associated with ADHD through the possibility of causing neurodevelopmental disorders. It is known that HMGB1 is effective in the diagnosis and prognosis of immune system diseases. Therefore, our results show that HMGB1 may be related to the pathophysiology of ADHD.