Objective: The aim of this paper is to assess personality disorder (PD) comorbidity in somatization disorder (SD) patients compared with psychiatric controls in a Spanish sample.
Methods: This is a case-control study. Selection of 70 consecutive SD patients was made, and an age-, sex-, and ethnic-group-matched control group of 70 mood and/or anxiety disorder patients recruited in psychiatric outpatient clinics was selected. PDs were measured using the International Personality Disorder Examination, and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Axis I morbidity was measured by means of the Standardized Polyvalent Psychiatric Interview.
Results: PD comorbidity in SD patients was 62.9%, compared to 28.2% in controls [odds ratio (OR)=3.7; 95% confidence interval (95% CI)=1.8-7.6]. The highest ORs of PD in SD patients, compared with controls, were for paranoid (OR=9.2; 95% CI=1.9-43), obsessive-compulsive (OR=6.2; 95% CI=1.2-53.6), and histrionic (OR=3.6; 95% CI=0.9-13.9) PDs.
Conclusions: This is a controlled study with the largest sample of SD patients. The prevalence of PD comorbidity is similar to that of a previously published controlled study but is different from those of the most frequent PD subtypes.