Around one in 20 people suffers from a personality disorder, according to new research.
A study by St Bartholomew's Hospital published in the British Journal of Psychiatry has found that obsessive-compulsive disorder (OCD) was the most common condition, affecting around two million in the UK including footballer David Beckham.
The study claims that men are more likely to suffer disorders than women, with antisocial personality disorder affecting five times more males than females.
The one exception was schizotypal disorders, which were found to be as common in men as women.
Professor Jeremy Coid from the University of London commented on the findings to the Independent.
"The question is, where should you divert your resources? Do you put them down the line when people might be showing severe manifestations, or at the earlier stage when you might be able to prevent something happening?"
He added that those with criminal convictions or who had been in care were more likely to suffer from disorders.