After listening to a public talk, a mother lingered to ask whether or not her 23-year-old son -- recently thwarted in his college studies by serious depression and anxiety -- should have a brain MRI to see if there is something abnormal. At a neighborhood diner, another concerned mom wondered if psychological testing for her adolescent daughter might decipher the origins of her child’s struggle with anxiety and eating problems. At work, a worried father asked if gene testing would be helpful to understand his daughter’s psychiatric illness, which had recently erupted.