In my experience, it's easier to get up in the morning when you feel like your life has purpose. And, according to a new study, a purpose-filled life also makes it easier to fall (and stay) asleep at night. Neurologists at the Northwestern University Feinberg School of Medicine explored the relationship between purpose in life and sleep issues in older adults. More meaningful, goal-oriented lives, researchers found, were associated with better sleep quality and lower risk for two sleep-related disorders, sleep apnea and Restless Leg Syndrome (RLS).
Psychologists make careers out of defining and measuring unwieldy feelings and concepts. The squishy notion of "purpose in life," for instance, is defined as "a sense of meaning and directedness in their life, essentially having aspirations and goals for the future and feeling that experiences in life are meaningful." And, in past research, purpose in life has emerged as a protective factor against various diseases and health snafus, including cardiac disease, depression, early death and, of course, shuteye troubles.
The association between living a non-hollow existence and logging top-notch Zzzs has been the focus of a few different studies. And, in general, fulfilling lives and restful nights appear to go together. In one 2004 study, for instance, older women whose lives were brimming with purpose exhibited less body movement at night, suggesting high sleep quality. And another study, in which researchers tackled the purpose-sleep issue from the other direction, reported a link between lower levels of purpose and unhealthy sleep duration (meaning either too much or too little sleep). Those were both cross-sectional studies, meaning they examined the relationship between two factors at a single moment in time. But in a 2010 longitudinal study — meaning a study based on data collected on the same people repeatedly over time — those who reported higher levels of purpose at the outset of the study were least likely to experience disrupted sleep later on. So, the purpose-sleep link has held up across different types of research.
Authors of the current study sought to build on the sleep-and-purpose literature by examining both overall sleep quality and sleep disorders that are especially common in older people. The study involved 800 participants, 60-99 years old, who were recruited from Chicago-area senior living facilities. Because studies have found a higher incidence of disturbed sleep, as well as greater susceptibility to sleep-disordered breathing, in black Americans (compared to white ones), researchers intentionally recruited both (and only) black and white participants. But the results didn't show any race-based differences.
Participants filled out questionnaires on sleep, sleep disorder symptoms and life purpose at the outset of the study. For the life-purpose questionnaire, participants had to determine the extent to which they agreed with statements such as "I feel good when I think of what I’ve done in the past and what I hope to do in the future” and “some people wander aimlessly through life, but I am not one of them.”
Researchers also followed up with patients one, two and three years after the study began to track any changes in sleep. Overall, higher levels of purpose predicted better sleep quality, both at the outset and one year later. High-purpose participants were also less likely to develop sleep apnea, as well as report RLS and sleep apnea symptoms, one and two years later.
The findings could be interpreted in two ways, researchers wrote. First, it's possible that people with purpose-filled lives reported better, less disordered sleep because people who lead purpose-filled lives also lead happier, less disease-ridden ones. Less disease --> fewer sleep complaints. Alternatively, people who live for something meaningful might be more likely to make healthy lifestyle choices and engage in good-for-you behaviors, such as exercise, regular medical visits and relaxing recreational activities. In turn, these healthy behaviors might lead to a lower risk of developing sleep apnea and RLS.