Impact of Subthalamic Nucleus Deep Brain Stimulation on COGnitive and PSYchiatric Symptoms in Parkinson's Disease

With this study, the investigators want to investigate how deep brain stimulation (DBS) affects various cognitive and psychiatric symptoms of Parkinson's disease (PD). In particular, they will examine whether stimulation of the left hemisphere has a different effect than stimulation of the right hemisphere on cognitive and psychiatric symptoms.

Inclusion Criteria: * Diagnosed with Parkinson's disease * Treated with subthalamic nucleus deep brain stimulation (STN-DBS) * For part I: General research consent for the analysis of routine clinical data * For part II of the study: ability to provide informed consent * native German or French speaker * Montreal Cognitive Assessment with score ≥ 20 Exclusion Criteria: * Atypical Parkinsonism * Other disease affecting the brain (e.g. Alzheimer's disease, vascular dementia, multiple sclerosis, stroke, traumatic brain injury, non-provoked epilepsy, brain tumour, etc.) * Haemorrhage during implantation of STN-DBS, which resulted in permanent cognitive or physical impairment * Schizophrenia, ongoing substance abuse, bipolar disorder or autism * For part II: Severe depressive disorder and/or suicidality * Insufficient quality or lack of brain imaging data pre and/or post STN-DBS