Lets not get carried away. There are some cautions that those using the depression poll need to be careful of before making assumptions. Since Mormonism will most likely come up, it needs to be remembered that Utah residents are not all Mormons and not all Mormons are active members. There is also a curious fact about the numbers, as reported:
The survey, which takes about 15 minutes, involved 42 core questions. Those taking the survey could get a score of up to 100. The actual difference between states wasn't great: The average score for the highest-ranking state, Utah, was 69.2 points, while the average for the lowest-ranking state, West Virginia, was 61.2 points.
In other words, Utah is neither more depressed or more happy than anyone else in the United States. That means that, in all likelihood, Mormons aren't any mentally worse off than other people. It is hard to see how this relates to the other study that found, according to an ABC News article on the subject:
According to MHA, some 10.14 percent of adults in Utah "experienced a depressive episode in the past year and 14.15 percent experienced serious psychological distress. ... Individuals in Utah reported having on average 3.27 poor mental health days in the past 30 days."
Both studies, like all studies of this nature, are probably flawed in their own ways. Reporters have an even worse tendency to conclude causation where nothing concrete exists. In the meantime, I am going to remain happy that it appears (if past "logic" holds) Mormons are at least as happy as everyone else.