# Time to add two new disorders to neuropsychiatric aspects of Parkinson’s disease

## TL;DR

This paper argues for recognizing two new neuropsychiatric disorders in Parkinson’s disease: somatic symptom disorders and bipolar spectrum disorders, which have important implications for treatment.

## Contribution

The paper introduces the novel idea that somatic symptom disorders and bipolar spectrum disorders are significant and under-recognized aspects of Parkinson’s disease.

## Key findings

- Somatic Symptom Disorders/Somatoform Disorders significantly contribute to the Parkinson’s disease phenotype.
- Bipolar Spectrum Disorders are epidemiologically linked to Parkinson’s disease and may share neurobiological mechanisms with impulse control disorders in PD.

## Abstract

Recent reviews have explored Parkinson’s Disease (PD) through psychiatric lenses. However, emerging literature allows to go beyond psychosis, depression, and impulse control disorders. Two key emerging themes are prominent: firstly, studies accrued in the past 13 years challenge prevailing views by demonstrating Somatic Symptom Disorders/Somatoform Disorders (SSD-SD) significantly participate in the PD phenotype, with relevant treatment implications. Secondly, epidemiological data reveal a link between Bipolar Spectrum Disorders (BSD) and PD, prompting a reconsideration of Impulse Control Disorder/Hedonistic Homeostatic Dysregulation (ICD/HHD) in PD. Furthermore, behaviors akin to BSD symptoms during manic states are observed in PD, suggesting shared neurobiological underpinnings.

Our proposed review tackles these themes, dissecting the impact of SSD-SD on PD and highlighting the BSD-PD convergence. This approach has implications for tailored psychotherapeutic techniques targeting psychosomatic and functional neurologic disorders within the context of PD care. Moreover, recognizing the blurred lines between neurology and psychiatry in PD underscores the importance of a holistic, interdisciplinary approach.

As these findings challenge established assumptions and offer new avenues for patient care, we must promote our understanding of PD’s intricate neuropsychiatric dimensions.