CUHK Study: Major Depressive Disorder Patients With Rapid Eye Movement Sleep Disorder Are More Likely to Suffer From Brain Degeneration

A recent research study from the Faculty of Medicine at CUHK has confirmed that immediate family members of patients with both “depressive disorder,” and "REM sleep behavior disorder" are more likely to develop symptoms of dementia. (Adrian Yu/The Epoch Times)

A recent study conducted by CUHK Faculty of Medicine confirms that immediate family members of patients with co-morbidities of Major Depression Disorder (MDD) and rapid eye movement sleep behavior disorder (RBD) are more likely to show signs of brain degeneration.

According to CUHK Faculty of Medicine, major depressive disorder is a common psychiatric disorder. Patients not only suffer from emotional disturbances and behavioral disorders but are also at risk of developing Parkinson’s disease and cognitive disorders in the long run. Many patients, especially those with major depressive disorder, also suffer from RBD. The Department of Psychiatry, Faculty of Medicine, CUHK published an early study in 2022, indicating that 1 in 11 patients with major depressive disorder was diagnosed RBD, and the incidence rate is nearly 10 times higher than that of the general public.

According to Huang Bei, Research Assistant Professor of the Department of Psychiatry, Faculty of Medicine, CUHK, it is quite common for patients with major depression to suffer from RBD at the same time. These patients have more pre-biomarkers and signs of brain deterioration, such as olfactory deficits, color blindness, and decreased dopamine transmission in the striatum, than patients with major depression disorder only, reflecting a higher risk of brain degeneration in major depressive disorder comorbid RBD patients.

To further confirm the risk of brain degeneration associated with the psychiatric co-morbidity RBD, a team from the Department of Psychiatry at CUHK conducted a four-year family study that recruited 1,371 participants, including immediate family members without psychiatric disorders (the healthy control group), immediate family members with psychiatric disorders (the psychiatric control group), and immediate family members of patients with psychiatric co-morbidities RBD (the psychiatric co-morbidities RBD group), to compare the incidence rate of α-synucleinopathy neurodegeneration features between family members of psychiatric patients with RBD and without RBD.

The results showed that the “psychiatric comorbid RBD group” had a higher level of α-synucleinopathy features than both the “healthy control group” and the “psychiatric control group”, including the diagnosis of RBD and its main symptoms, a pre-degenerative biomarker of brain degeneration, and a confirmed diagnosis of Parkinson’s disease or cognitive impairment.

Findings Enhance Precision Psychiatry Studies

Wang Jing, an honorary postdoctoral researcher at the Department of Psychiatry, said that the results of the study prove that RBD, a comorbid psychiatric disease, cannot be simply regarded as a drug-induced phenomenon, but is a potential cause of brain degenerative diseases.

Professor Wing Yun-kwok, Head of the Department of Psychiatry, believes that the study not only clarifies the characteristics of RBD as a comorbid psychiatric disease for independent diagnosis but also reveals that depression patients diagnosed with RBD through sleep examination have a potential risk of brain degeneration, which can be regarded as one subtype of depressive disorder. From a perspective of degenerative brain disorders, there is a need to systematically identify psychiatric patients with RBD, especially those with major depressive disorder, and prioritize interventions to prevent brain degeneration for these patients.

He added that from the perspective of psychiatric management, psychiatric disorders with co-morbid RBD could be defined as a subtype in order to provide the most appropriate management options and to promote precision psychiatry.

The research results have been published in the “Journal of Neurology, Neurosurgery, and Psychiatry.”