The causes of psychiatric disorders are poorly understood. Recent models propose that many early onset disorders that are commonly comorbid might reflect the varying expression of overlapping risk factors. The mediating processes remain largely unknown, but three factors show some promise: adolescent externalizing traits, early life adversity, and midbrain dopamine D2 autoreceptors. To investigate whether these features acquire greater predictive power when combined, a longitudinal study was conducted in youth who have been followed since birth.Cohort members were invited to participate based on externalizing scores between 10 to 16 years of age. At age 18 (age 18.5 ± 0.6 y.o.), 52 volunteers who met the entry criteria had a 90-min positron emission tomography scan with [ 18 F]fallypride to image dopamine D2 autoreceptors, completed the Childhood Trauma Questionnaire, and were assessed with the Structured Clinical Interview for DSM-5. The three-factor model identified those with a lifetime history of DSM-5 disorders with an overall accuracy of 90.4% (p = 2.4 x 10 -5 ) and explained 91.5% of the area under the receiver operating characteristic curve [95% CI: .824, 1.000]. Targeting externalizing disorders specifically did not yield a more powerful model than targeting all disorders (p = 0.54).The model remained significant when including data from participants who developed their first disorders during a three-year follow-up period (p = 3.5 x 10 -5 ). Together, these results raise the possibility that a combination of temperamental traits, childhood adversity, and poorly regulated dopamine transmission increases risk for diverse, commonly comorbid, early onset psychiatric problems, predicting this susceptibility prospectively.