How is good and poor sleep in older adults and college students related todaytime sleepiness, fatigue, and ability to concentrate?

We compared good sleepers with minimally and highly distressed poor sleeper s on three measures of daytime functioning: self-reported fatigue, sleepine ss, and cognitive inefficiency. In two samples (194 older adults, 136 colle ge students), we tested the hypotheses that (1) poor sleepers experience mo re problems with daytime functioning than good sleepers, (2) highly distres sed poor sleepers report greater impairment in functioning during the day t han either good sleepers or minimally distressed poor sleepers, (3) daytime symptoms are more closely related to psychological adjustment and to psych ologically laden sleep variables than to quantitative sleep parameters, and (4) daytime symptoms are more closely related to longer nocturnal wake tim es than to shorter sleep times. Results in both samples indicated that poor sleepers reported more daytime difficulties than good sleepers. While low- and high-distress poor sleepers did not differ on sleep parameters, highly distressed poor sleepers reported consistently more difficulty in function ing during the day and experienced greater tension and depression than mini mally distressed poor sleepers. Severity of all three daytime problems was generally significantly and positively related to poor psychological adjust ment, psychologically laden sleep variables, and, with the exception of sle epiness, to quantitative sleep parameters. Results are used to discuss disc repancies between experiential and quantitative measures of day time functi oning. (C) 2000 Elsevier Science Inc. All rights reserved.