Long-Term Neurocognitive Outcomes of Childhood-Onset Bipolar Disorder in Nigerian Adolescents: A Five-Year Follow-Up Study

Childhood-onset bipolar disorder is associated with progressive neurocognitive impairment, yet no longitudinal neurocognitive follow-up data from African pediatric bipolar populations exist. This five-year longitudinal study examines neurocognitive outcomes in Nigerian adolescents with childhood-onset bipolar disorder compared to healthy controls and adolescents with attention deficit hyperactivity disorder (ADHD). Eighty adolescents with childhood-onset bipolar disorder, 80 with ADHD, and 80 healthy controls will be recruited at baseline from pediatric psychiatry clinics in Lagos, Kano, and Ibadan, with follow-up assessments at 12, 36, and 60 months. The Cambridge Neuropsychological Test Automated Battery (CANTAB) will assess executive function, working memory, attention, and psychomotor speed at each wave. Clinical variables including mood episode frequency, medication adherence, cumulative antipsychotic exposure, and educational attainment will be tracked. Latent growth curve modeling will examine neurocognitive trajectories and identify clinical moderators of decline. This study constitutes a seminal longitudinal neurocognitive investigation in African child psychiatry, generating original data on developmental trajectories of bipolar disorder that will inform treatment and educational support guidelines for affected adolescents in Nigeria. Keywords: childhood-onset bipolar disorder, neurocognition, longitudinal, adolescents, Nigeria