New guidelines announced by the National Institute for Health and Clinical Excellence (NICE) say that changing attitudes within the NHS towards personality disorders could reduce their cost to society.
The health watchdog said its recommendations would improve the prevention, management and treatment of people with anti-social personality disorder and borderline personality disorder.
In the past, the conditions - both of which affect thought, emotions and behaviour - were thought to be untreatable.
Sufferers should be treated in an "atmosphere of hope and optimism", NICE said, with medical staff urged to use psychological therapies to prevent the development of problems.
Around two million people in the UK have personality disorders, with anti-social personality disorder (ASPD) and borderline personality disorder the most common.
People with (ASPD) exhibit behaviour that can be harmful to other people such as impulsiveness, anger, recklessness and deceitfulness.
Those with borderline personality disorder have symptoms including emotional ups and downs, problems with relationships and self-harming.
According to NICE, the conditions should be treated as a whole - rather than with drugs prescribed for particular symptoms - and without any stigma.
Among its recommendations was for mental health trusts to set up specialist teams with expertise in the disorders.