I have studied the American life very nicely. They have a good heart. The only thing that is wanting is Krsna consciousness. For want of this Krsna consciousness, despite all your opulences, you are becoming confused and frustrated. I hear that out of three, one man is a patient of a psychiatrist. Why? Why are you unhappy? Why should you be unhappy? You have got everything–enough food, land, money, intelligence. Why should you be unhappy? The cause of this you should try to find out. The cause is that without Krsna consciousness, without God consciousness, nobody can be happy.

From Srila Prabhupada lilamrta 47: Preaching to America: Part 2