In the literature, disagreement exists on the impact of Axis II comorbidity on the treatment outcome of depression. The aim of the present study was to examine in a naturalistic treatment setting the 1-year outcome and treatment characteristics of depressed adolescent outpatients with and without comorbid Axis II disorders. The 151 participants were interviewed for Axis I and II diagnoses at baseline and follow-up. Those diagnosed with a personality disorder were significantly more impaired at follow-up than those without. The given treatment did not differ between the two groups in length, intensity, or hospitalization, but the group with Axis II comorbidity received more psychotropic medication. The treatment outcome of depression was poorer for the group with Axis II disorders compared to those without. In conclusion, a personality disorder diagnosis is a sign of more severe overall symptoms. Special attention should be paid to Axis II traits when planning and conducting the treatment of adolescent depression.