In 1989, Don Baker wrote a book of the above title about the therapeutic effects of thankfulness. The Apostle Paul told the Thessalonians to "give thanks in all circumstances, for this is God's will for you in Christ Jesus" (I Thes. 5:18). But let's be honest; for most of us thankfulness is not natural; we're 'complainers,' by nature. But the therapeutic effect of thankfulness is that it can help us transcend our circumstances.
Please note that Paul doesn’t ‘command’ us to give thanks FOR all circumstances, but IN all circumstances—which challenges us to find reasons to be thankful even in the worst times. Look at a very abbreviated list of David’s Psalms of “Thanksgiving." King David thanks God for His holiness (7:17), His works (9:1), His guidance (16:7), for hope and salvation, and the joy of His presence (16: 9-11).
When you find yourself in “hard-to-thank-you-God” circumstances, these Psalms can help you transcend your troubles. Paul reminds us we have a God who causes everything to work together for the good of those who love Him and are called according to His purpose (Rom. 8:28). Our circumstances may or may not change, but as we align ourselves with God's purposes, we transcend our circumstances. And that is the real therapeutic benefit of thankfulness.