Dreams and rapid eye movement sleep in the multiple sleep latency test.

Dreams are closely associated with rapid eye movement (REM) sleep. The purpose of this study was to evaluate the reliability of dreams in predicting the presence of REM sleep during naps of the multiple sleep latency test (MSLT). We prospectively analyzed MSLTs performed in the evaluation of 44 patients with excessive daytime sleepiness. A total of 167 naps were studied. The patients' ages ranged from 11 to 69 years (mean 45 years). There were 26 males and 18 females. The relationship between the presence of reported dreams and the presence of REM sleep was as follows: sensitivity (percentage of naps with REM in which dreams were reported), 59%; specificity (percentage of naps without REM in which no dreams were reported), 63%; positive predictive value (probability that REM occurred if dreaming is present), 29%; and negative predictive value (probability that REM did not occur when no dreaming is present), 85%. In the daytime naps of the MSLT, the presence of reported dreaming did not appear to be a reliable indicator of the presence of REM sleep in the preceding nap.