The effects of RBD medications on dream content: A critical review of evidence.
Sleep Medicine October 21, 2025 DOI: 10.1016/j.sleep.2025.106878 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Systematic review Qualitative Peer reviewed |
|---|---|
| Interventions | Clonazepam benzodiazepines melatonin melatonin receptor agonists levodopa pramipexole dopamine agonists |
| Topics | Dreaming |
| Key findings | The review reports only limited evidence that clonazepam, melatonin, and pramipexole reduce disturbing dream content, while more consistent but preliminary evidence links levodopa to increases in vivid or disturbing dreams, including nightmares. The authors argue that widespread methodological limitations across the 27 studies constrain the interpretability and comparability of these findings. |
Abstract
REM sleep behavior disorder, often an early marker of α-synucleinopathies, is characterized by the loss of REM-related muscle atonia and the occurrence of dream enactment behaviors. Dream reports in REM sleep behavior disorder are frequently described as more vivid, violent, and negative than typical dreams. However, evidence for this remains inconsistent, likely due to methodological variability and unaddressed confounds - most notably, the influence of pharmacological treatments. The extent to which medications affect REM sleep behavior disorder dream content remains poorly understood. This systematic review critically evaluates the literature on the effects of medications commonly used in REM sleep behavior disorder and Parkinson's disease - including clonazepam, other benzodiazepines, melatonin, melatonin receptor agonists, levodopa, pramipexole, and other dopamine agonists - on dream content. We identified 27 relevant studies employing qualitative and/or quantitative methods. Our analysis revealed major methodological limitations across studies, including a lack of standardized protocols and definitions, frequent reliance on retrospective or anecdotal reports, and predominantly qualitative or semi-quantitative assessments. These limitations constrain the interpretability and comparability of findings. Available evidence offers only limited support for clonazepam, melatonin, and pramipexole in reducing disturbing dream content. More consistent, but still preliminary, evidence links levodopa to increases in vivid or disturbing dreams, including nightmares. This review highlights the need for rigorously controlled studies using standardized and reproducible methods to clarify the role of pharmacological treatments in shaping dream content in REM sleep behavior disorder. Future research should also integrate retrospective and prospective data-collection designs to account for potential recall biases.
Comparable studies
Other systematic reviews and meta-analyses on dreaming, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Dreaming as mind wandering: evidence from functional neuroimaging and first-person content reports. | 2013 | Systematic review with meta-analytic comparison | |
| Lucid dreaming incidence: A quality effects meta-analysis of 50 years of research | 2016 | Meta-analysis | |
| The effectiveness of lucid dreaming therapy in patients with nightmares: A systematic review. Adults with chronic and recurring nightmares | 2023 | Systematic review | |
| The relationships between insomnia, nightmares, and dreams: A systematic review Individuals without a concomitant psychopathology, including those with insomnia or... | 2024 | Systematic review | |
| Psychosocial treatments for nightmares in adults and children: a systematic review | 2023 | Systematic review |
Citations in the library
Cites 16
- Questionnaires and diaries as research instruments in dream research: Methodological issues. Dreaming March 1, 2002
- Measuring nightmare and bad dream frequency: impact of retrospective and prospective instruments Journal of Sleep Research May 13, 2008
- The Language of Dreams: Application of Linguistics-Based Approaches for the Automated Analysis of Dream Experiences Clocks & Sleep September 19, 2021
- Cognitive Bizarreness in the Dream and Waking Mentation of Nonpsychotic Patients With Parkinson’s Disease The Journal of Neuropsychiatry and Clinical Neurosciences October 1, 2010
- We are the Sensors of Consciousness! A Review and Analysis on How Awakenings During Sleep Influence Dream Recall. Nature and Science of Sleep 2025
and 11 more in the library