Incidence, characteristics and course of narrow phenotype paediatric bipolar I disorder in the British Isles

Area of Science:

• Child and Adolescent Psychiatry
• Epidemiology
• Mental Health Surveillance

Background:

• Narrow phenotype bipolar I disorder (NPBDI) is a specific subtype of bipolar disorder.
• Early diagnosis and management of NPBDI in young people are crucial for long-term outcomes.
• Understanding the incidence and clinical characteristics of NPBDI in under-16s is essential for public health planning.

Purpose of the Study:

• To estimate the surveillance incidence of first-time NPBDI diagnoses in individuals under 16 years old in the British Isles.
• To describe the symptoms, comorbidities, associated factors, management, and 1-year clinical outcomes of NPBDI in this age group.
• To inform child and adolescent psychiatry (CCAP) services about the prevalence and trajectory of NPBDI.

Main Methods:

• Active prospective surveillance epidemiology was employed.
• 730 consultants in child and adolescent psychiatry (CCAP) participated.
• The child and adolescent psychiatry surveillance system was used to report NPBDI cases.

Main Results:

• 33 cases met the DSM-IV criteria for NPBDI among 151 reported cases (age 10-15.11 years).
• The minimum 12-month incidence of NPBDI was 0.59 per 100,000 in the British Isles.
• Irritability (72%), comorbidities (51.5%), hospital admissions (48.5%), and relapses (56.67%) were common during 1-year follow-up.

Conclusions:

• First-time NPBDI diagnoses in individuals under 16 by CCAP in the British Isles are infrequent.
• The observed rates of relapse and hospital admission necessitate vigilant monitoring.
• These findings underscore the importance of early identification and ongoing management strategies for pediatric NPBDI.