Bipolar disorder in a 12-year-old: the first manic episode in early-onset bipolar disorder can be atypical

The diagnosis of early-onset bipolar disorder (EOBD) remains a major clinical challenge due to overlapping symptoms with other childhood psychiatric conditions and its divergence from adult presentations. There has been significant controversy over the phenomenology of EOBD due to the “Pediatric Bipolar Disorder” (PBD) proposed phenotypes, which, unlike adult mania, are often characterized by chronic irritability, affective instability, and mixed mood states rather than episodic euphoria. This case report presents B., a 12-year-old boy admitted for suicidal ideation and severe mood dysregulation. His history revealed early hyperactivity, oppositionality, progressive social withdrawal, somatic complaints, and persecutory ideation. Clinical assessment identified a major depressive episode with mixed features, supported by psychometric evidence of affective, anxiety, and somatic symptoms, as well as a cyclothymic–hypersensitive temperament. Treatment with lithium salts and aripiprazole led to significant clinical improvement, confirming the bipolar spectrum nature of his disorder. This case underscores the complexity of diagnosing “hidden bipolarity” in children, where irritability, anxiety, and subthreshold manic symptoms may obscure bipolar pathology. Although bipolar disorder was significantly overdiagnosed in prepubertal children in the past, B.'s case illustrates that rare peripubertal presentations can indeed manifest the phenomenological features described in the pediatric bipolar disorder literature.