Up to now hardly any quantitative research regarding diagnosis of personality disorders in the environment of Consultation-Liaison Psychiatry and Psychosomatic Medicine is available.

The data of 3032 patients aged 17-65 years seen between 1988 and 1997 at the Mount Sinai Hospital in New York, NY, were recorded and analyzed using the Micro-Cares Database System.

19,7% (N=598) of patients exhibited a personality disorder. Out of those 7,7% distributed to Cluster A (Odd or Eccentric Behavior), 54,3% to Cluster B and 38,0% to Cluster C.

89% of patients with personality disorders showed at least one additional specific psychiatric disorder.

Patients with a personality disorder had a lower incidence of somatic disease, but exhibited a higher level in psychosocial impairment and a higher comorbidity in substance abuse. During the previous year they used psychiatric treatment more often and were in need of a more intense social and psychotherapeutical treatment.

The age group of 17-40 year old patients with a personality disorder was hospitalized shorter and had less of a lag between hospitalization and time of psychiatric consultation.

More reasons for a psychiatric consultation were given when patients with a personality disorder were referred.

In the environment of Consultation-Liaison Psychiatry and Psychosomatic Medicine every 5th to 6th patient requires a specific, psychiatric, psychotherapeutic or social treatment because of a personality disorder.

The classification of personality disorders into clusters did not yield an additional benefit.