Establishing successful relationships with patients who are suffering from personality disorders can be quite challenging for health care providers, yet these patients are common in medical practice. Complications associated with patients with comorbid personality disorders are myriad, including suboptimal utilization of medical care (over- and under-use), difficulty adhering to treatment plans, and more problematic relationships with clinicians. In addition, these patients are more likely to be hospitalized. An understanding of personality disorders allows physicians to anticipate the challenging interpersonal and behavioral problems that can arise in working with these patients and can help physicians work through the negative emotions that working with such patients may arouse. This facilitates the development and implementation of appropriate treatment plans, improved alliance between patient and clinician, and better outcomes.
The current edition of the American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders, 4th edition, Text Revision (DSM-IV-TR) defines personality disorder as:
an enduring pattern of inner experience and behavior that deviates markedly from the expectations of the individual's culture, is pervasive and inflexible, has an onset in adolescence or early adulthood, is stable over time, and leads to distress or impairment.
People suffering from personality disorders have dysfunctional beliefs about self and others, and impaired capacity to establish and maintain relationships with others, function at work, and experience pleasure in life. These patients have difficulty negotiating complex situations and coping with stress and anxiety. The sick role and the demands of medical care can be particularly problematic for them. The stress of illness is often extreme and sets into motion defensive and inflexible emotional processes, cognitions, and behaviors—with negative consequences for their medical treatment. In addition, these patients' difficulties in relating to others manifest themselves in the doctor–patient relationship. They may be quite demanding or disrespectful of the needs of others, or they may experience such anxiety when they need to trust or confide in others that they avoid building relationships.
Personality theorists have long debated how best to understand and classify personality disorders. The debate has centered on two models. The categorical model, adopted by DSM-IV, views personality disorders as entities that are distinct from one another—that is, classified in separate categories—and also distinct from normalcy. This model blends more easily with traditional medical diagnosis than does the dimensional model, which views personality disorders as entities that overlap each other and that are not distinct from normalcy, so that the maladaptive traits of patients with personality disorders represent normal traits that are exaggerated.
In fact, both models hold some truth. Some personality disorders, such as schizotypal and paranoid, may belong to a spectrum of illness that includes psychotic Axis I disorders and are thus better explained by a categorical model. Other personality disorders, such as histrionic and obsessive-compulsive personality, may depict exaggerated normal traits, reinforcing the concept of a dimensional model.