Sleep onset latency (SOL), the length of time that it takes to accomplish the transition from full wakefulness to sleep, during midlife could lead to lower life satisfaction, according to a study conducted at Ohio Northern University.

The research was performed under the supervision of Dr. Megan Clegg-Kraynok, ONU assistant professor of psychology. The data was collected as part of Midlife in the United States II (MIDUS II), a national study funded by the National Institute on Aging.

Respondents with higher life satisfaction reported shorter sleep onset latency (SOL). Sleep onset delay among those with low life satisfaction could be the result of worry and anxiety, as reported elsewhere. These findings support the idea that life satisfaction is interlinked with many measures of sleep and sleep quality, suggesting that improving one of these variables might result in improving the other.

“These findings support the idea that life satisfaction is interlinked with many measures of sleep and sleep quality, suggesting that improving one of these variables might result in improvement in the other,” said lead author Hayley O’Hara, a 2015 Ohio Northern psychology graduate.

The research abstract was published in an online supplement of the journal Sleep and was presented Monday, June 8, in Seattle, Wash., at SLEEP 2015, the 29th annual meeting of the Associated Professional Sleep Societies LLC.

The study group comprised 3,950 adults. Fifty-five percent were female and ranged in age from 28 to 84. A six-item life satisfaction survey was used to code participants as having low, medium and high levels of satisfaction, and a subjective measure of minutes it takes to fall asleep was used to measure SOL.