Subclinical Manic Symptoms in Children with Autism Spectrum Disorder.

Background: Children with autism spectrum disorder (ASD) have varied comorbidities. With regard to comorbidity, there has been increasing interest in bipolar disorder (BP) in children. However, the prevalence of BP with ASD has varied because of the methodological differences used. Therefore the adequate criteria for determining BP in children are still debated. The purpose of this study is to identify reliable prevalence of BP and to evaluate a variety of subclinical BP symptoms in children with ASD.

Methods: This is a cross-sectional and case-control study. The participants were 110 referred children aged 6-15 years: 46 with ASD (the case group), 64 without ASD (the control group). We used the strict operational criteria for diagnosing BP, and assessed the presence of subclinical BP symptoms using a semi-structured diagnostic interview.

Results: None of the children were diagnosed with BP in the case group, although two children were diagnosed with BP in the control group. Based on the subclinical BP symptoms, the prevalence of elation/expansive mood and racing thoughts was significantly higher in the case group than in the control group: 26.1% versus 3.1% (p<.001) and 32.6% versus 9.4% (p=0.002), respectively.

Conclusions: Our finding indicates that school-aged ASD children frequently present subclinical BP symptoms. It is important to be aware of over-diagnosis of BP, even though the children present subclinical BP symptoms, and to provide -the children with effective treatments.