Peripheral markers of nitrosative stress in children with autism spectrum disorder and bipolar disorder comorbidity during euthymic phase

Background: Bipolar Disorder (BD) is often comorbid with Autism Spectrum Disorder (ASD) (Skokauskas & Frodl, 2015). However, to our knowledge, the etiological pathways of BD comorbidity in individuals with ASD was not given a particular focus in the literature. The present study aims to investigate the link between BD comorbidity and nitrosative stress in children and adolescents with ASD. Method: The case group consisted of 41 participants with comorbid ASD and BD, while the control group consisted of 39 participants with ASD who did not have any past or present mood disorders. As indicators of nitrosative stress, serum levels of NO (Nitric Oxide), NO2/NO3 (Nitrite/Nitrate), 3-NT (3-Nitrotyrosine) and NOS-I (Nitric Oxide Synthetase-I) were compared between groups. Results: Serum levels of NO and 3-NT were significantly higher in the case group. As the phenomenological findings of BD, the age of onset was 10.5, mixed attack rate was 70%, seasonality rate was 63.8%, and sub-threshold symptoms were seen in 36.6% of the cases. Conclusion: The present study indicated a relationship between BD comorbidity and nitrosative stress cascade among children and adolescents with ASD. Further studies with larger samples are needed to better understand the etiology of BD comorbidity in patients with ASD.