Personality disorders are a form of mental illness in which a person can have inflexible and unhealthy thinking patterns, general functioning, and behaviour. They typically have difficulty perceiving and relating to others and can have mood and other emotional and psychological issues.
Personality disorders usually begin to emerge in teenage years or early adulthood but are believed to form in childhood due to a combination of genetic and early environmental factors. Many people with personality disorders have often also suffered some form of trauma, emotional abuse, neglect, or early attachment disruption from a primary care giver.
It is thought that personality disorders occur as result of a complex interplay between negative childhood experiences (including abuse and neglect,) environment (such as being raised by parent with a mental isness, substance abuse, aggression, or poor boundaries issues), and genetic factors (including predisposition, mental, and physical health).
Personality disorders lie on a spectrum, along with normal personality traits meaning people can have some features or symptoms without having a diagnosis of this disorder.
Many symptoms however, of different personality disorders overlap and many people with one personality disorder also have signs and symptoms of at least one additional personality disorder.