Background: The prevalence of psychiatric comorbidity in Parkinson's disease (PD) is about 50%. Objective: The authors investigated differences among PD patients treated by deep brain stimulation (DBS), by drugs alone (noDBS), and healthy control subjects. Method: Samples of 22 subjects in each group were assessed with the Temperament and Character Inventory (TCI) and Hamilton scales for anxiety and depression (Ham-A and Ham-D). Results: Higher scores emerged on two Novelty-Seeking subscales in PD-DBS patients. Ham-A and Ham-D scores were lower in PD-DBS patients than in PD-noDBS patients and control subjects. Rigidity and non-impulsiveness were lower in PD-DBS than in PD-noDBS patients. Conclusion: Further studies should investigate whether or not these changes in personality are a consequence of the motor and depression improvement after DBS.