Age of Onset of Bipolar Affective Disorder in Females

General Age Distribution

The peak ages at onset for bipolar disorder in the general population range from 15 to 30 years, with prevalence rates increasing with age until this peak period, according to the American Academy of Child and Adolescent Psychiatry 1, 2
The median age for first affective syndrome is 23 years, though the mean age is slightly higher at 28.3 years, with the most common age of onset being 15-19 years 1, 2

Early-onset bipolar disorder (before age 13) is predominantly male, while the sex distribution equalizes in adolescent and adult-onset cases, as reported by the American Academy of Child and Adolescent Psychiatry 3
Females with early-onset bipolar disorder (before age 18) represent a significant proportion and are actually overrepresented in the early-onset group compared to males when examining clinical samples, although the exact proportion is not specified in the provided references 3

Childhood onset (<13 years) represents a distinct onset period, with an average age of onset of 7.3 ± 3.5 years in research samples, and is most strongly associated with family history of mood disorders, according to the American Academy of Child and Adolescent Psychiatry 4
Adolescent onset (13-18 years) represents approximately 43% of all bipolar cases and frequently presents with psychotic symptoms, markedly labile moods, and mixed features, as reported by the American Academy of Child and Adolescent Psychiatry 5, 6
Adult onset (>18 years) represents approximately 35% of cases and is characterized by a more classic cyclical presentation with clearer episode demarcation, according to the American Academy of Child and Adolescent Psychiatry 1, 7

Females with early-onset bipolar disorder show a four- to sixfold increased risk if they have first-degree relatives with affective disorders, as reported by the American Academy of Child and Adolescent Psychiatry 3
Females with early-onset bipolar disorder also show even higher degrees of familiality in early-onset, highly comorbid cases, according to the American Academy of Child and Adolescent Psychiatry 3