Personality disorder comorbidity among patients with bipolar I disorder in remission

Background: Comorbid personality disorders have been shown to be a prominent factor affecting symptom severity and course in bipolar disorder (BD) patients. Bipolar patients with personality disorder had more relapses, poorer prognosis and worse treatment response than those without an axis II diagnosis. Objective: We evaluated the prevalence rate of comorbid personality disorder in 74 bipolar I disorder cases who were in remission and tried to elucidate the possible relationship between comorbid axis II disorders and prognosis, severity and treatment features of BD cases. Methods: Diagnosis of all personality disorder comorbidities was evaluated using the Structured Clinical Interview for DSM-III-R Axis-II Disorders (SCID-II), while the general psychopathology level was assessed using the Symptom Check List (SCL-90-R). A questionnaire for acquiring sociodemographic and clinical variables was also used. Results. Sixty-two per cent of bipolar I patients in this sample had at least one comorbid axis II disorder. The most common comorbid cluster of personality disorder was cluster C (48.6%), followed by cluster A (25.7%) and cluster B (20.3%) personality disorders. Assessment of demographic and clinical variables revealed that bipolar patients with comorbid personality disorder were mainly female, had multiple affective episodes, and had attempted suicide more often than patients without personality disorder. Conclusions: The results of this study suggest that comorbid personality disorder might alter the course of BD and result in a poorer prognosis and more severe psychopathology. Further prospective controlled studies minimizing the bias of interviewers and other confounding factors would help us to understand the pure impact of personality disorder on the course of BD, its prognosis and response to treatment