Developmental differences according to age at onset in juvenile bipolar disorder

Area of Science:

• Child and Adolescent Psychiatry
• Neurodevelopmental Disorders
• Mood Disorders

Background:

• Bipolar disorder (BD) diagnosis in children and adolescents requires understanding early-onset characteristics.
• Previous research has not fully elucidated the specific clinical differences between childhood-onset and adolescent-onset BD.

Purpose of the Study:

• To investigate distinct clinical features of childhood-onset bipolar disorder compared to adolescent-onset BD.
• To explore differences in severity, functional impairment, course, mood, co-morbidity, and treatment outcomes.

Main Methods:

• A cohort of 136 children and adolescents diagnosed with BD using DSM-IV criteria and KSADS-PL interview were analyzed.
• Patients were categorized into childhood-onset (before 12 years) and adolescent-onset groups.

Main Results:

• Childhood-onset BD (58.8%) was more prevalent in males and associated with higher rates of attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD).
• An episodic course was less common in childhood-onset BD (42.5%) compared to adolescent-onset BD (76.8%).
• No significant differences were observed in severity, 6-month treatment outcome, prevalent mood, or co-morbid anxiety between the groups.

Conclusions:

• Early-onset bipolar disorder may represent a distinct subtype characterized by a more persistent, subcontinuous course.
• Childhood-onset BD is strongly associated with co-occurring ADHD and ODD, highlighting the need for targeted interventions.