Rehab center Diamond Rehab Thailand wanted to take a look at how our environment affects our state of mind so they did some research and found that South Dakota is the LEAST stressed state in the US. They took into consideration things like mental and physical stress percentages and only less than 9% of the residents in South Dakota reported those stressors. Hawaii is second on that list followed by ILLINOIS with only 10% of citizens reporting suffering frequently from mental distress. Then comes Alaska and Maryland rounding out the top 5. The MOST stressed state on the list was West Virginia.