This 44-item test, developed by Oliver P. John, Ph.D. and V. Benet-Martinez in 1998, is in the public domain and has been normed on tens of thousands of adults. It provides a score for each of the Big Five personality traits (Conscientiousness, Agreeableness, Emotional Stability, Extroversion and Intellect or Openness).
Scores on these traits can often explain important issues for adults and thus simplify counseling efforts. For example, an extrovert working as a night janitor was depressed. Finding a day job, where he could relate to other people, went a long way toward relieving his depression.