Parkinson’s Disease (PD), a progressive neurodegenerative disorder predominantly affecting older adults, continues to pose significant challenges in clinical management, particularly regarding its non-motor symptoms. Among these, sleep disturbances have emerged as critical factors complicating quality of life and disease prognosis. In a recent eye-opening investigation, Alqahtani and Aldurdunji conducted a comprehensive review of late-stage interventional trials registered on ClinicalTrials.gov, specifically focusing on studies reporting sleep-related outcomes in elderly PD populations. This analysis, published in BMC Geriatrics in 2026, sheds new light on the current landscape of clinical research targeting sleep abnormalities in Parkinson’s disease, revealing gaps and opportunities that could transform future therapeutic approaches.
Sleep disorders in Parkinson’s disease encompass a spectrum of manifestations, including insomnia, rapid eye movement (REM) sleep behavior disorder (RBD), excessive daytime sleepiness, and fragmented sleep architecture. These conditions are not merely coexistent but often exacerbate the motor symptoms and cognitive decline inherent to PD, underscoring the importance of their identification and management. Despite this significant clinical impact, the extent to which interventional clinical trials incorporate or prioritize sleep-related endpoints has remained unclear until this registry review. By mining the data from ClinicalTrials.gov, the authors offer an unprecedented snapshot of ongoing and completed trials that address these crucial facets.
The methodology employed in this review involved meticulous extraction and analysis of clinical trial records registered up to early 2026, highlighting studies that explicitly incorporated sleep outcomes as primary or secondary endpoints. This approach provided a quantitative and qualitative assessment of the state of research, including trial designs, sample sizes, sleep assessment tools used, and types of interventions tested. The findings uncovered a surprisingly limited number of late-stage interventional studies (phase III or IV) with robust sleep outcome measures, revealing a considerable research gap. This scarcity of advanced trials focused on sleep outcomes contrasts sharply with the high prevalence and debilitating impact of sleep disturbances in PD patients.
Importantly, the review highlights the heterogeneity of outcome measures employed across trials, ranging from subjective sleep diaries and questionnaires like the Parkinson’s Disease Sleep Scale to objective measures including polysomnography and actigraphy. This variability complicates the comparability of results and the synthesis of evidence needed for clinical guidelines. The authors emphasize the urgent need for standardized, validated sleep assessment tools tailored for PD populations to facilitate more rigorous and clinically relevant trial designs. Such standardization would enhance the reliability of data on therapeutic efficacy and safety profiles of interventions targeting sleep disturbances.
When evaluating the types of interventions studied, the review notes that pharmacological approaches dominate the landscape, with dopaminergic agents, melatonin, and hypnotics frequently tested. However, there is an emerging interest in non-pharmacological strategies such as cognitive-behavioral therapy for insomnia (CBT-I), light therapy, and physical exercise, which are gradually gaining attention in trial protocols. The authors advocate for expanded research into integrative treatment paradigms combining pharmacological and behavioral modalities, reflecting a holistic approach to managing PD-associated sleep disorders. This shift aligns with evolving concepts of personalized medicine aimed at optimizing individual patient outcomes.
The review also scrutinizes the representation of older adults in these trials, a population disproportionately affected by both Parkinson’s disease and its sleep complications. A critical finding is that many studies exclude participants above certain age thresholds or those with comorbidities commonly seen in older individuals, thereby limiting generalizability. This underrepresentation raises ethical and scientific concerns, as aging-related factors profoundly influence both disease progression and treatment responses. The authors call for more inclusive trial designs that reflect the real-world demographic and health profiles of PD patients, enabling more applicable and effective therapeutic recommendations.
The temporal aspects of the analyzed trials reveal another pressing issue: the majority are short-term studies, often extending over weeks to a few months, insufficient to capture the chronic and fluctuating nature of sleep disturbances in Parkinson’s disease. Longitudinal studies with extended follow-up periods are indispensable for understanding long-term efficacy, safety, and potential adaptation phenomena associated with interventions. The authors suggest that future clinical trial frameworks incorporate extended monitoring to better address the complexities of sleep issues in the context of a progressive neurodegenerative disorder.
Alarmingly, the review indicates a lack of integration between multidisciplinary care approaches in current trial designs. Sleep disorders in PD are multifactorial, influenced by neurological, psychological, and environmental factors. Trials that involve multidisciplinary teams including neurologists, sleep specialists, psychologists, and physiotherapists could substantially enhance the depth and applicability of findings. The authors highlight the potential for integrated care models to not only improve sleep outcomes but also mitigate overall disease burden, representing a fertile ground for future clinical research innovation.
Another critical dimension discussed pertains to biomarkers and neurophysiological correlates of sleep disturbances in PD. Despite advances in understanding neurodegeneration-associated changes in sleep architecture through imaging and electrophysiological methods, these biomarkers are rarely incorporated as outcome measures in interventional trials. The authors advocate for embedding neurobiological endpoints within clinical studies to unravel mechanistic insights and stratify patient subgroups more effectively. Such biologically informed trial designs could enable precision-targeted therapies, marking a paradigm shift in Parkinson’s disease management.
The review’s findings underscore the need for enhanced funding and scientific focus on this overlooked facet of PD research. Sleep disturbances have profound socioeconomic and healthcare implications, exacerbating disability and caregiver burden. Addressing this gap requires concerted efforts from the scientific community, funding bodies, pharmaceutical industry, and patient advocacy groups. The authors urge stakeholders to prioritize sleep-related endpoints in future trial programs, ensuring resource allocation aligns with unmet clinical needs and the lived experiences of patients.
In the broader context of neurodegenerative diseases, the insights provided by this review have far-reaching implications. Sleep disorders are prevalent across various conditions such as Alzheimer’s disease and multiple system atrophy, suggesting that advances made within PD sleep research could inform multi-disease therapeutic strategies. This translational potential highlights the value of cross-disciplinary collaborations and harmonized clinical trial methodologies, fostering innovation and accelerating the discovery of effective treatments.
The evolving technological landscape offers promising tools to revolutionize sleep assessment and intervention delivery in Parkinson’s disease. Wearable devices, home-based polysomnography systems, and digital therapeutics present opportunities for real-time monitoring and personalized treatment adaptations. The authors recognize the importance of integrating these technologies into trial protocols to enhance data granularity and patient engagement. Future interventional studies incorporating digital health innovations could pave the way for more accessible and scalable solutions to the pervasive problem of sleep dysfunction in PD.
The review by Alqahtani and Aldurdunji ultimately serves as a clarion call to the research community, stressing that sleep-related outcomes must become integral components of Parkinson’s disease clinical trials. Advancing this agenda will require methodological rigor, inclusivity, interdisciplinary collaboration, and technological integration. By committing to these principles, the scientific and medical communities can better address the multifaceted challenges posed by sleep disturbances in older adults with PD, improving therapeutic outcomes and patient quality of life globally.
In summary, the meticulous registry review conducted by the authors provides a foundational framework for future research directions in Parkinson’s disease. It elucidates the current shortcomings in addressing sleep-related outcomes within late-stage interventional trials and charts a course for more comprehensive, patient-centered studies. As treatment paradigms evolve alongside growing understanding of PD pathophysiology, sleep medicine emerges as a vital frontier ripe for exploration through innovative clinical trials, ultimately promising to reshape the lives of millions affected by this debilitating disorder.
Subject of Research:
Late-stage clinical interventional trials reporting sleep-related outcomes in older adults diagnosed with Parkinson’s disease.
Article Title:
Late-stage interventional trials reporting sleep-related outcomes in older adults with Parkinson’s disease: a ClinicalTrials.gov registry review.
Article References:
Alqahtani, F.J., Aldurdunji, M.M. Late-stage interventional trials reporting sleep-related outcomes in older adults with Parkinson’s disease: a ClinicalTrials.gov registry review. BMC Geriatr (2026). https://doi.org/10.1186/s12877-026-07089-3
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