Personality disorders tend to have similarities and as such are grouped together according to their key characteristics.
People with personality disorders which fall into the Eccentric ...
Mental illnesses and disorders are far more common that we thought, say, even 30 years ago. Some of the reasons are that specialists know more and are better educated and researched.
There is still much to learn about personality disorders. Defining the condition can be a little difficult because of how it differs from one person to the next.