... DRD4Association in ADHD Individuals Using a Statistically DerivedQuantitative Trait for ADHD in a Family-Based Association Test. BiologicalPsychiatry 2007, 62(9):985-990.22. Lasky-Su J, Anney ... section), the diagnostic subtype,family status, and gender resulted in a final model thatretained only main effects and two-way interactions, butno three- and four-way interactions. The likelihood ... additional heterogeneity in the sample, as demonstrated by the present contribution.Additionally, a diagnostic procedure invariant to age,gender, and informant, as used in the IMAGE study, may have...