The diagnostic stability of comorbid personality disorders among patients with depression remains unclear. A total of 262 patients suffering from first-episode depression were assessed using the Structured Clinical Interview for DSM-IV Axis II Personality Disorders (SCID-II) and reassessed after 5 years. A total of 87 patients (33%) were diagnosed with a personality disorder at baseline, and 63 of them (72%) maintained a personality disorder diagnosis at follow-up (kappa coefficient 0.71). At cluster level, 63% maintained a diagnosis within cluster B and 48% maintained a cluster C disorder across the follow-up period (kappa coefficients of 0.54 and 0.64, respectively). Hence, comorbid personality disorders cannot be taken just as artifacts of the depressive mood that will remit spontaneously or with further treatment of the primary depression. Furthermore, the stability of personality disorders diagnoses was not predicted by clinical characteristics of the depression, nor of the course of the affective disorder during followup.