It's a question that is so difficult to answer. It's not like having a cold-you can't simply wake up with an anxiety disorder because you forgot to wash your hands before eating. Anxiety disorders are forged over years of experiences. They have a genetic component, an upbringing component, an environmental component.
The Missouri Office of Administration recently released new population projections for Missouri and its counties. Missouri's population is expected to approach 6.8 million people in 2030, a growth of roughly 1.2 million people from the year 2000, which will represent a 21% increase in the state's population.
St. Louis has a 2014 population estimated at 317,000 in the city limits, but the Greater St. Louis area is the 19th largest metro area in the US with a population of 2.85 million. St. Louis enjoyed its highest population during the 1950's, when it was home to 857,000 people and ranked 8th in the country. The city was still the largest in Missouri in 1980, but it has since been dwarved by Kansas City.