Serum interleukin-6 level in unmedicated adults with attention-deficit/hyperactivity disorder – preliminary report

Aim: The aim of the study was to compare adults suffering from attention-deficit/hyperactivity disorder with healthy controls, in terms of their serum concentrations of inflammatory cytokine interleukin-6. Materials and methods: The diagnosis of attention-deficit/hyperactivity disorder was established during the interview with the clinician on the basis of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. A total of 36 participants with attention-deficit/hyperactivity disorder and 28 in the control group were included. The age range was 21–55 years. Individuals with a psychiatric comorbidity, allergy, chronic inflammatory disease, and receiving psychostimulant treatment were excluded. Results: Adults diagnosed with attention-deficit/hyperactivity disorder had higher serum concentrations of interleukin-6 in comparison to healthy controls. Conclusions: The aetiology of attention-deficit/hyperactivity disorder may be influenced by the concentration of inflammatory factors.