The truth is out there. Not the truth about space aliens, but a truth about how to sabotage negative thinking and beat depression that often comes with it.

When we are depressed we close ourselves down, until our world is very small. Left alone it can even get so small that are thoughts are all we hear, and our depression is all we see.

What to do? Get up, get out there, and make someone else's day.

One little discussed feature of depression is that it does not multi-task well. It wants you to concentrate on feeling bad, which it depends on to feed itself. When you begin thinking about making someone else happy, it gets confused, and goals what to do.

Depending on how depressed you are, getting out there may not be easy. It works best when you are in the vague, gray stages. But it can be a lifeline to keep you from sinking further down.

The marvel of deliberate kindness. We've probably seen bumper stickers encouraging us toward “random acts of kindness.” And that's a wonderful idea. But to short circuit the stages of depression, it works best to be deliberate about what you want to do.

Being deliberate helps you focus on being friendly for other people's sake, and to forget about yourself for a while. You are not going out to put on a brave face, or parade how sad you feel. Your purpose is to go out and spread some sunshine for a change.

Here's how it works.

It's pretty simple, really. Go to the grocery store, the mall, or run some errands that need doing. Greet each salesperson or checker with a great big smile. Look them right in the eye, ask how they are … and really mean it. Call them by name, and allow yourself to feel genially grateful that they have been there on their feet all day, just so you could shop.

I can not explain what happens, but I have experienced it time after time. Maybe our faces actually change. Maybe we simply start to feel better. But people do respond. They do smile back far more specifically than their little canned greeting requires them to do. And you are on the receiving end of all those smiles.

When we do this enough, our own smiles feel more comfortable. They rest on our faces like they belong there. Strangers walking by may start to comment on what a lovely day it is. We may hum a happy song.

Let your mind enjoy a vacation.

After you've been outside smiling at people, you can also find a quiet place to smile at yourself. A walking meditation in a park, or sitting quietly, allows your mind to appreciate this chance to lighten up.

Take in all that positive energy that other people have given you, and just bask for a while in feeling good. Be thankful for everyone you met today, and be glad you made someone smile.