Study objectives: To assess prospectively the emotional content of dreams in individuals with the obstructive sleep apnea hypopnea syndrome (OSAHS) and sleepy snorers.
Methods: Prospective observational study. Forty-seven patients with sleepiness and snoring attending a sleep-disordered breathing clinic, completed a morning diary concerning pleasantness/unpleasantness of their dreams for 10 days, and then had AHI assessed by a limited-channel home sleep study. Participants and groups: Sleepy snorers, AHI < 5: n = 12 (mean age = 51.00 years [SD 7.01], 7 males); AHI 5 -14.9, n = 14 (mean age = 49.71 y [9.73], 12 males); AHI ≥ 15, n = 21 (mean age = 56.33 [11.24], 16 males).
Results: All groups reported similar numbers of dreams and nightmares during the diary period. The AHI ≥ 15 group were significantly higher on dream unpleasantness than were the sleepy snorers (p < 0.05); and when only males were analyzed, this difference was also significant (p = 0.01). As AHI increased across the 3 groups, there was a significant decrease in variability of dream emotions (Levene test for homogeneity of variance between the 3 groups, p = 0.018). Mean daytime anxiety and daytime depression were significantly correlated with mean dream unpleasantness and with mean number of nightmares over the diary period.
Conclusions: Patients with AHI ≥ 15 had more emotionally negative dreams than patients with AHI < 5. The variation in mean dream emotion decreased with increasing AHI, possibly because sleep fragmentation with increasing AHI results in fewer and shorter dreams, in which emotions are rarer.
Keywords: Obstructive sleep apnea; dreams; nightmares; snorers.