Parkinson's disease (PD) is primarily defined by cardinal motor symptoms such as slowness of movement (bradykinesia), tremor, and rigidity. Despite the recent surge in interest in non-motor symptoms and prodromal biomarkers, the psychological and cognitive dimensions of PD retain limited attention and require further sensitization and understanding. In this overview, we aimed to identify the psychological and cognitive characteristics associated with PD and to present recent data on their prevalence, underlying mechanisms, and current treatments. We conclude here that among numerous non-motor symptoms, patients with PD exhibit a wide range of dysfunctions in cognition, emotion, motivation, and social interaction, along with an increased suicide risk and unique personality profiles.Such dysfunctions often appear as prodromal indicators of PD, preceding for years the complete and canonical symptomatic picture-profile-phenotype of parkinsonism. Their various possible causes have been overviewed and some of them dissected, including pathophysiological alterations linked to PD per se, psychosocial impact, and side effects of PD treatments. In view of their major medical and social impact, we emphasize here the need for more specific mental care, targeted therapies, and multi-scale research on the psychological and cognitive dimensions of PD, which are deleterious to patients and affect their quality of life.