Elevated serotonin levels in children with autism spectrum disorders: behavioral manifestations and association with immune dysfunction

Aim. To demonstrate that elevated serotonin levels in children with autism are linked to gastrointestinal dysfunction and hyperactivation of the immune system.

Materials and methods. Over a period of one and a half years (from 15 January 2023 to 15 July 2024) 680 children diagnosed with conditions classified under F84 (autism spectrum disorders, including atypical autism) were analyzed at the “Verum” medical clinic. The study involved the assessment of whole blood serotonin levels, as well as immunological markers such as immunoglobulin E and eosinophilic cationic protein.

Results and conclusion. The results confirmed that a significant proportion of children with autism exhibited elevated serotonin levels, consistent with findings from previous research. The association between elevated serotonin levels and behavioral disturbances, including self-injurious behaviors (such as pinching, head-banging, and scratching) and motor stereotypies (repetitive movements), was noted. Additionally, a correlation was observed between elevated serotonin and immune system dysfunction, reflected in increased immunoglobulin E and eosinophilic cationic protein levels. Stabilization of the gastrointestinal tract and immune system was associated with a reduction in serotonin levels and an improvement in negative behavioral symptoms.