A longitudinal study of people with personality disorders suggests that disabling symptoms may be far more flexible and liable to decrease over time than traditionally thought, according to an article in the October issue of the Archives of General Psychiatry.

One of the cardinal assumptions in psychiatry and psychology has long been that individuals who have personality disorders will have persistent, enduring symptoms and that treatment offers little hope of change. In fact, the official diagnostic nomenclature in the DSM-IV of the American Psychiatric Association describes these disorders as “inflexible” and “stable over time.”

The American researchers associated with the Longitudinal Study of Personality Disorders evaluated 250 patients with personality disorders at three time points over a four-year period with use of the International Personality Disorders Examination. Stability and change in personality disorder features over time were examined with use of individual growth modeling.

“On average, our subjects showed a decline of 1.4 personality disorder features per year,” noted Mark F. Lenzenweger, MD, lead author of the study.

What is particularly fascinating about this finding is that the change is not explained by exposure to conventional treatments or the presence of another form of mental disorder, such as anxiety, depression, or other illnesses. Instead, researchers found that people under treatment had elevations in rate of change in trajectory of symptom decline but not a change in trajectory itself.

Personality disorders are relatively common among the public, with approximately 10% of the population affected, and they make up a large proportion of individuals seen for treatment by practicing mental health professionals.

“Although the disorders are common, with 1 in 10 people affected, the good news is that we now know the disorders can change with time,” said Lenzenweger.

The recent emergence of specialized treatments for personality disorders coupled with these new findings creates new hope for those affected with the conditions.