1. A computer implemented process comprises: determining by one or more computers one or more data sets of words associated with multiple groups having different mental states define multiple cohorts; executing by one or more computers a classification model of a first group to classify against a second group, with the first and second groups being of the multiple groups; determining by one or more computers points of intersection of words between the first group and the second group; and determining by one or more computers words that are unique to each group to provide isolated statistically predictive terms from the multiple groups for predictive features for corresponding ones of the multiple cohorts.