Rêves et émotions chez des sujets souffrant du trouble comportemental en sommeil paradoxal
REM sleep behavior disorder (RBD) is a parasomnia characterized by vivid dreams and loss of muscle atonia usually present during REM sleep that allows the appearance of dream-enacting behaviors that are isomorphic to dream content. Several studies have examined the content of RBD patients’ dreams, many found a greater presence of threatening and aggressive themes, others obtained mixed results. Most studies had significant methodological shortcomings, such as a lack of a control group or the inclusion of patients taking psychoactive medication. Still, the presence of dysphoric dreams is associated with marked psychopathology and emotional regulation problems. Moreover, the reason why RBD patients have dysphoric dreams is largely unexplored, just as parts of the processes that generate the dream-enacting behaviors.  The goal of the first article of this thesis was to measure alexithymia and nightmare distress among RBD patients compared to a control group. The results indicate that RBD patients suffer more from alexithymia, especially a greater difficulty in identifying their emotions and that this difficulty correlated with nightmare distress. The second article examined, using a validated questionnaire, the lifetime prevalences of patients’ typical dream themes, and estimated the presence of their dreams, nightmares and dream theme diversity. RBD patients reported significantly more nightmares than controls and more menacing themes, such as assaults, disasters, and where the dreamer lacks control. The third article was intended to clarify discrepancies in the results of studies on RBD dreams, that is, if the aggressiveness reported by patients is really a difference in dream content or rather a problem related to dream distress. A second objective was to measure the degree of correlations between waking-state behaviors such as mirror behaviors, and dream-enacting behaviours in RBD patients. RBD patients were found to have more dysphoric dreams, containing more anxiety. They were also feeling greater distress in reaction to their dream experiences than did controls. Moreover, their results on the mirror behavior questionnaire correlated with the severity of their dream-enacting behaviors, suggesting that the mirror neuron system could have an influence in the formation of these behaviors.  Overall, these findings suggest that difficulties in emotional regulation could explain both patients’ daytime emotional symptoms (alexithymia, nightmare distress, depression, anxiety, fewer mirror behaviors) and nocturnal difficulties (nightmares and dysphoric dreams, threats in dreams). We suggest that a deficit in frontal regulatory regions could be the base of the different challenges faced by patients. More specifically, it is possible that abnormalities in the mirror neuron system have an impact on both patients' ability to regulate their emotions and the manifestation of dream-enacting behaviors.
REM sleep behavior disorder dreams nightmares alexithymia