A 16-year prospective study of prodromal features prior to BPI onset in well Amish children.

Background: Longitudinal research of well Amish children over 16 years to identify the pattern and frequency of prodromal symptoms/behaviors associated with onset of BPI disorder during childhood or adolescence.

Methods: Parental informants were interviewed annually using structured and semi-structured interviews to record medical, developmental and behavioral/symptomatic data for their children in two samples. The bipolar sample had 115 children with a BPI parent. The control sample had 106 children of well parents, with and without a positive family history for mood disorders. A panel of clinicians assigned risk ratings independently and blind to family relations.

Results: Eight children, age 13 or older, onset with BPI in the bipolar sample compared with one in the control sub-sample (well parent of a BPI sibling). The specific "pre-school" behaviors/symptoms that most identified children with BPI from well children in control samples were: sensitivity, crying, hyper-alertness, anxiety/worry and somatic complaints. During school years, parents reported mood (sad) and energy changes (low not high) decreased sleep and fearfulness as key symptoms.

Limitations: The sample of 9 BPI onsets is small. However, a variable age of onset means many children remain at risk. Although not statistically significant, 34.6% of the bipolar sample youngsters carry risk ratings compared to 15.2% among controls.

Conclusions: The miniclusters of prodromal features that emerged pre-school (ages 1-6), were "episodic" through childhood (7-12) and appeared to mimic adult recurrent illness. Prepubertal onset with mania did not occur. The pattern of prodromal symptoms has clinical relevance for its potential predictive value for onset with BPI disorder and early intervention.