It's rarer to have a string of stressed-out days in Hawaii than in any other state, WebMD Health News reports today.

WebMD cites a study published in the American Journal of Preventive Medicine that is based on about 2.4 million American adults who participated in CDC surveys from 1993 to 2001 and 2003 to 2006.

Participants were asked by phone how many of the previous 30 days their mental health — including stress, depression and emotional problems — was "not good."

People who said their mental health was "not good" at least 14 out of the previous 30 days had "frequent mental distress," according to researchers.

The study doesn't pinpoint the causes of mental distress.

Here's the percentage of adults with frequent mental distress in each state for both time periods combined.

1. Hawaii: 6.6%

2. South Dakota: 6.7%

3. Washington, D.C.: 7.4%

4. Kansas, Nebraska, and North Dakota: 7.5%

5 . Arizona: 7.6%

6. Iowa and Montana: 7.7%

7. Illinois: 7.9%

8. Connecticut: 8%

9. Wisconsin: 8.1%

10. Minnesota: 8.2%

11. North Carolina: 8.4%

12. Alaska, Maryland, Vermont: 8.5%

13. Ohio, Wyoming: 8.6%

14. New Jersey: 8.7%

15. New Hampshire, Oklahoma: 8.8%

16. Maine, Virginia: 9%

17. Washington: 9.2%

18. Colorado, Louisiana, Pennsylvania, South Carolina: 9.3%

19. Idaho, Tennessee: 9.4%

20. Massachusetts, Georgia, Utah: 9.5%

21. New York: 9.6%

22. New Mexico, Rhode Island, Texas: 9.7%

23. Delaware: 9.8%

24. Missouri: 9.9%

25. Oregon: 10%

26. Arkansas, Florida, California: 10.1%

27. Indiana: 10.3%

28. Michigan: 10.5%

29. Alabama, Mississippi: 10.8%

30. Nevada: 10.9%

31. West Virginia: 11.2%

32. Kentucky: 14.4%

http://www.webmd.com/balance/news/20090413/distressed-not-so-much-in-hawaii