Low illumination experienced by San Diego adults: association with atypical depressive symptoms.

We explored the illumination exposure of middle-aged adults to determine normal values and to explore several correlates of daily light exposures. Subjects aged 40-64 years in San Diego, CA were recruited by random telephone dialing. Subjects completed a demographic interview and the Center for Epidemiologic Studies Depression self-rating scale (the CES-D) supplemented with eight questions related to seasonal affective disorders (SAD). Data were analyzed for 106 volunteers who wore a device that monitors illumination exposures and activity. The median subject was exposed to illumination > or = 1000 lux for only 4% of the time observed, that is, only about 58 min per day were spent in daylight. Subjects scoring higher on the atypical SAD mood symptoms spent less time in bright illumination rs = -0.266, p = 0.003. The CES-D depression score was similarly correlated with illumination but of borderline significance (rs = -0.150, p = 0.063). These results suggest the hypothesis that many Americans may be receiving insufficient light exposure to maintain optimal mood.

Sleep apnea and periodic movements in an aging sample.

Individuals 65 years of age and older were randomly selected, from a primarily white upper-class population, to participate in a study of sleep disorders in elderly adults. One hundred forty-five volunteers had a brief telephone interview, a home interview, and a portable sleep recording using the Medilog and Respitrace systems. By research classifications, we found that 18% of the elderly participants had sleep apnea (apnea index greater than 5), 34% had periodic movements in sleep (myoclonus index greater than 5) (PMS), and 10% had both sleep apnea and PMS. These were not clinical diagnoses. The home recording indicated that the individuals with PMS slept significantly less than other older adults.