If we stacked up all the books on how to be happy, the pile might reach into the stratosphere.

Now there's something of a backlash going on. Professor Eric G. Wilson says the ideology of constant happiness has people in its grip. In his book, Against Happiness, he says they read self-help manuals, watch feel-good TV, eat comfort food and pop pills, all to avoid the blues that are an inevitable part of the human condition.

Cherishing our melancholy, he says, lets us absorb the insight it provides. We should feel what we must feel: insecurity, shock, turbulence, anxiety and grief. In this way, we experience the beauty of the world with all its indifference.

In his 2007 book, The Loss of Sadness: How Psychiatry Transformed Normal Sorrow Into Depressive Disorder, New York University's Jerome Wakefield says feeling down after your heart is broken, even so down that you meet the criteria for clinical depression, is normal. But today's sufferers want a pill instead of learning from the situation.

Wakefield says the backlash that we are seeing now could be an end of the drive for ever-greater heights of happiness.

Ed Diener and Robert Biswas-Diener's book Rethinking Happiness is due out later this year. They say 85 percent of Americans report that they are pretty happy. But the happiness industry says that's not enough, and that you almost have a duty to be happier.

The backlash comes just when the most extensive study on happiness has been released. It shows the highest levels of happiness go along with the most stable, longest and contented relationships.

It also shows that on a happiness scale of 1 to 10, those who said they were 8's were more successful, better educated and earned more.

One problem with acknowledging sadness and depression: You get no sympathy. Friends and co-workers just want you to snap out of it.