Parkinson's disease (PD) affects more than 4 million people in the 10 most populous countries, a number that is projected to more than double to 9.3 million by 2030.1 In the United States alone, its prevalence amounts to approximately 1% to 2% of people older than age 65 years.2 With the aging population in the US, prompt diagnosis and evidence-based management of PD will be paramount for a successful multidisciplinary approach, which is often led by neurologists and psychiatrists.
PD is classically defined by the presence of motor symptoms including bradykinesia, resting tremor, and rigidity. Although the motor symptoms of PD typically prompt medical attention, non-motor symptoms in PD are prevalent and disabling. Unaddressed non-motor symptoms, such as mood disorders, impulse control disorders, cognitive impairment, and psychosis, are an opportunity for a provider to intervene and improve patient quality of life and reduce caregiver burden.
In the first article, “Mood Disorders in Parkinson's Disease,” for this issue of Psychiatric Annals, Drs. Sarah Mufti and Kathrin LaFaver bring to the forefront the clinical presentation, diagnosis, and evidence-based management for depression, anxiety, and apathy in PD. Drs. Mazen T. Elkurd and Richard B. Dewey Jr. distill decades of research in the article, “Cognitive Impairment and Dementia in Parkinson's Disease,” and review differences in presentation and treatment strategies for mild cognitive impairment and dementia in PD. In the third article, “Impulse Control and Related Disorders in Parkinson's Disease: Special Issues and Implications,” Drs. Gregory M. Pontone and Howard D. Weiss highlight the obstacles and challenges to the diagnosis and treatment of impulse control disorders in PD. The last article, “Psychosis in Parkinson's Disease,” by Dr. Matthew Remz and myself reviews the clinical manifestations and spectrum of PD psychosis and proposes an evidence-based approach to its management.
These articles provide insight into the clinical manifestations of non-motor symptoms, hypotheses related to their pathophysiology, and treatment recommendations founded on the latest available evidence. Taken together, they represent an indispensable foundation for physicians taking care of patients with PD and define the paths of greatest scientific impact for future research.
- Dorsey ER, Constantinescu R, Thompson JP, et al. Projected number of people with Parkinson disease in the most populous nations, 2005 through 2030. Neurology. 2007;68(5):384–386. doi:10.1212/01.wnl.0000247740.47667.03 [CrossRef] PMID:17082464
- Marras C, Beck JC, Bower JH, et al. Parkinson's Foundation P4 Group. Prevalence of Parkinson's disease across North America. NPJ Parkinsons Dis. 2018;4(1):21. doi:10.1038/s41531-018-0058-0 [CrossRef] PMID:30003140