Depressive symptoms can negatively influence patient reported disease severity after subthalamic nucleus stimulation for Parkinson's disease.

BackgroundDepression can negatively influence an individual's perception of their disease. Although subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment for Parkinson's disease (PD), some patients do not appreciate benefits despite showing objective improvements in motor function.ObjectiveWe explored the impact of depressive symptoms on self-reported outcomes of PD severity in patients who underwent STN-DBS.MethodsAssessments took place preoperatively and 2-years after surgery. Patients completed the Hospital Anxiety and Depression Scale (HADS), Unified Parkinson's Disease Rating Scale (UPDRS) Parts 2 and 4, Gait and Falls Questionnaire, Parkinson's Disease Questionnaire-39 (PDQ-39), and the Non-motor Symptoms Scale. The UPDRS Part 3 (motor examination) was also performed. Patients were dichotomized into two groups (normal or high) based on their postoperative follow-up HADS depression score.ResultsEighteen patients (33.3%) were assigned to the high group (hHADS-D), and 36 patients (66.7%) were assigned to the normal group (nHADS-D). The UPDRS Part 3 OFF-medication score improved to a similar extent in both groups, and participants experienced a similar reduction in their levodopa equivalent daily dose following STN-DBS. Unlike the nHADS-D group, however, hHADS-D patients did not self-report improvements on any clinical outcome measure at follow-up from baseline, and instead indicated a significant worsening on the UPDRS Part 2 ON-medication and PDQ-39 cognition domain. This was not explicable by their preoperative non-motor symptom burden, nor changes in dopaminergic medications. There were no differences between groups in terms of proportion using anti-depressants, surgical complications or postoperative side effects.ConclusionsDepressive symptoms may play a significant role in subjective self-reporting, and should be carefully considered when evaluating STN-DBS effectiveness and managing patients postoperatively.