From a methodological point of view, the aggregation of several measurements reflecting the same construct is a common strategy to maximize the signal-to-noise ratio of the behaviors or characteristics of interest.21 For example, Kushner and colleagues22 obtained a positive association between alcohol dependence and an overall internalizing construct (based on both mood and anxiety symptoms). This trans-diagnostic measure, which drew items from several specific anxiety and mood diagnoses, was not improved by the addition of these diagnoses to their model. An additional advantage of aggregating across diagnoses is the decreased number of statistical comparisons needed.
