Google is working to help users make that important distinction, rolling out a feature this week that helps test for the mood disorder. Now, when users search for symptoms of depression, they will be directed to the PHQ-9 questionnaire, the standard tool doctors use to screen for depression. The clinically-validated survey quizzes respondents on a variety of trouble signs, such as feeling down and having trouble concentrating or poor appetite. The feature, which was developed in partnership with the National Alliance on Mental Illness, will be fully rolled out in the next couple of days. ... ... Some experts have...