This information is taken from several sources, as well as, my own experiences. To the best of my knowledge it is correct. If some part is not clear, let me know. They were described in medical literature over 100 years ago. It seems so but it could be due to better diagnoses, a greater public awareness, and more information being available.
Some people think our more stressful lifestyle is a contributing factor.
Yes, but more women than men seem to develop them. Some alcohol programs believe that some men tend to start drinking excessively in an effort to overcome anxiety. However, until diagnosed and assured, it is not uncommon for the people to feel they are going insane. In many cases no. They look and act as though nothing is wrong.