Aim: The aim of this study was to evaluate psychosocial functionality in patients with epilepsy using the Diagnostic Criteria for Psychosomatic Research (DCPR) classification system that aims to identify patients with clinically significant and relatively weighted psychological factors and to compare it with the Diagnostic and Statistical Manual of Mental Disorders (DSM). In addition, it was aimed to validate the DCPR system by investigating the effects of psychosomatic diagnoses on the quality of life in the disease process. Materials and Methods: One hundred consecutive patients with epilepsy who were referred to the Epilepsy special branch outpatient clinic were included in the study. The control group consisted of 53 healthy volunteers. All participants underwent structured DCPR and SCID-I interviews and were investigated using the Short Form-36 (SF-36) and a Sociodemographic Data Form. Results: Eighty-seven percent of the patients met the diagnostic criteria with the DCPR system while 82% of the patients met the diagnostic criteria with DSM (χ2(1, N =100) = 4.539, p = 0.04). Examination of the effect of diagnostic systems on SF-36 scores in patients with epilepsy with the hierarchical regression model showed that diagnoses in the DCPR system predicted most of the SF-36 subscale scores better. Conclusion: The DCPR system could detect psychological distress at a higher rate than DSM in patients with epilepsy. Syndromes in the DCPR classification were associated with poor quality of life in the patients. The DCPR classification is therefore valid in patients with epilepsy and may have advantages in a more comprehensive evaluation of patients.