Table 1.

A summary of studies that assessed dream recall in patients with sleep-disordered breathing.

References	Study sample and protocol	Dreams assessment tools	OSA diagnosis measures	Conclusions
Carrasco et al. (15)	20 consecutive patients with severe OSA and 17 healthy controls. PSG were recorded at baseline and during the CPAP titration night, 3 months after effective treatment and 2 years later in patients	Subjects were awakened 5–10 min after the beginning of the first and last REM sleep periods to measure percentage of dream recall, word count, thematic units, sleep architecture, and REM density	PSG	Dream recall was similar in patients at baseline and controls. Word count was higher in patients than in controls. Despite an increase in REM density, dream recall decreased the first months of CPAP and recovered 2 years later. Dream recall decreased with CPAP therapy and with normalization of sleep in OSA patients
Lovin et al. (26)	38 patients with OSA had a diagnostic study followed by a therapeutic study within 1–3 weeks	Dream recall was done immediately following spontaneous awakening from REM sleep	PSG	More patients recalled their dreams under CPAP than without CPAP
Schredl and Schmitt (27)	1,467 patients with OSA. And two representative samples from the general population	Questionnaire	PSG	Heightened dream recall frequency in patients compared to controls
Pagel and Kwiatkowski (28)	394 with severe OSA	A questionnaire with questions on dream and nightmare recall frequency	PSG	Both AHI and arousal index were significantly higher for the grouping reporting infrequent nightmare recall. Depressed nightmare recall may occur secondary to the REM sleep suppression that is known to occur in patients with significant OSA
Gorss and Lavie (25)	33 patients with OSA slept during two nights in the sleep laboratory. 16 were treated with CPAP) during the first night and 17 during the second. Patients were awakened for dream reports 10 min after the beginning of every REM period	Patients were asked upon awakening: “what was going through your mind before I woke you up?” Patients were also asked “how they felt in the dream” Dream reports were tape recorded.	PSG	After apneas, dream recall tended to be higher and dream reports were significantly longer
Schredl et al. (29)	762 patients who were diagnosed with different sleep disorders	Questionnaire	PSG	Dream recall frequency (DRF) of patients OSA did not differ from DRF in healthy controls. OSA parameters did not correlate substantially with DRF