Results: The modal response to the CLES was 0 (N=480),but an additional 276 subjects had CLES =1,and 363 subjects reported 2 or more traumatic lifetime events.Thedistribution of age at onset showed a broad peak between ages 12 and 18 ,with the majority of subjects having onset during that period, and a significant decrease in age of onset with the number of traumatic events.No single SNP showed a statistically significant interaction with the presence Of traumatic events to impact bipolar age at onset. However,SNPs in or near genes coding for calcium channel activity-related proteins(GeneOntology: 0005262) were found to be more likely than other SNPs to show evidence of interaction using the INRICH method (po0.001)