Everyone feels sad from time to time. But what happens when that sadness lasts a long time? Is it just a passing feeling or the medical condition known as depression? Many people do not know whether what they are feeling is a passing phase or a serious condition requiring treatment. They may not know where to turn to find out if they should get help. Google is trying to change that by helping people recognize whether what they are feeling is actually depression. The company has teamed up with the National Alliance for Mental Illness, or NAMI, to offer a questionnaire to people who search for the word "depression" on Google’s website.