Do dreams tell the future? Dream content as a predictor of cognitive deterioration in Parkinson’s disease
P. Bugalho, F. Ladeira, Raquel Barbosa, J. Marto, Cláudia Borbinha, Manuel Salavisa, Laurete da Conceição, Marlene Saraiva, Marco Fernandes, Bruna Meira
Journal of Sleep Research August 9, 2020 DOI: 10.1111/jsr.13163 (opens in new tab) via Semantic Scholar
Summary
AI-generated from the abstractIn Parkinson’s disease, negative emotions in dreams predict cognitive decline over four years. Among 58 non-demented patients, 23 reported dreams at baseline; aggression and negatively toned content predominated. Montreal Cognitive Assessment scores decreased significantly from baseline to follow-up. Negative emotion index in dreams was the strongest predictor of cognitive decline in a multivariate model, independent of motor stage, mood disorder, psychosis, or REM sleep behavior disorder. The findings suggest dream content may serve as an early marker of cognitive deterioration in Parkinson’s disease.
Study at a glance
| Characteristics | Prospective longitudinal cohort study Peer reviewed |
|---|---|
| Sample size | 58 |
| Population | Non-demented patients with Parkinson’s disease attending an outpatient clinic |
| Duration | 4-year follow-up |
| Keywords | Medicine Psychology |
| Key finding | Negative emotion index in dream reports at baseline was the strongest predictor of subsequent cognitive decline over four years in patients with Parkinson’s disease. |
Abstract
Cross‐sectional studies suggest a correlation between alterations in dream content reports and executive dysfunction tests in Parkinson’s disease (PD), but this has not been assessed in longitudinal studies. Our objective was to assess the predictive value of dream content for progression of cognitive dysfunction in PD. We prospectively addressed all consecutive, non‐demented patients with PD attending an outpatient clinic during a 1‐year period. Dream reports were collected at baseline by means of a dream diary and analysed according to the Hall and Van de Castle system. Patients were assessed at baseline for rapid eye movement sleep behaviour disorder, motor stage, mood disorder and psychosis. The Montreal Cognitive Assessment (MoCA) was applied at baseline and 4 years later. Linear regression analysis was used to the test the relation between each dream index (predictors), demographic and other motor and non‐motor variables (covariates), and change in MoCA scores (dependent variable). In all, 58 patients were assessed at both time points and 23 reported at least one dream (range 1–27, total 148). Aggression, physical activities, and negatively toned content predominated in dream reports. The MoCA scores decreased significantly from baseline to follow‐up. In the multivariate model, negative emotion index was the strongest predictor of cognitive decline. We found a significant positive association between negative emotions in dreams at baseline and subsequent reduction in MoCA scores. These findings suggest that some dream content in patients with PD could be considered a predictor of cognitive decline, independent of other factors known to influence either dream content or cognitive deterioration.