Reduced rCBF in Prefrontal Lobe is Involved the Bipolar Symptoms in Adolescents with Attention-Deficit/Hyperactivity Disorders

Background More than 50% of bipolar disorder (BD) patients have onset before age 20. Children with attention-deficit hyperactivity disorder (ADHD) may develop BD when they grow into adolescents. This study was designed to investigate early distinct regional cerebral blood flow (rCBF) in the presence of atypical bipolar symptoms in adolescents with ADHD. Methods and findings The study included 14 adolescents with ADHD comorbid BD (ADHD-BD) and 25 adolescents with ADHD only who were recruited at a university hospital. They were evaluated with the Kiddie-Schedule for Affective Disorders and Schizophrenia-Epidemiology version (K-SADS-E) by a child psychiatrist. Each subject underwent brain examinations using single photon emission computerized tomography (SPECT). Between-group differences in rCBF were analyzed with statistical parametric mapping. The ADHD-BD group had more severe symptoms of ADHD, more impulsiveness, more anxiety, poorer quality of life, and poorer adjustment; SPECT showed reduced rCBF in the right dorso-lateral prefrontal lobe, ventromedial prefrontal cortex, and hypothalamus compared to patients in the ADHD only group. The ADHD-BD group had increased rCBF in the left ventro-medial prefrontal cortex, right superior frontal lobe, left superior frontal lobe, premotor cortex, and supplementary motor area. Conclusion The abnormal rCBF might be involved in the pathophysiology of the development of BD in adolescents with ADHD.