The surprising association between saying thanks and sleeping well.
Gratitude - the ability to notice, acknowledge and reflect on the good things in life - has been associated with a variety of positive health and wellbeing outcomes, including improved sleep quality and quantity.
The first study to make a link between gratitude and sleep was conducted in 2003 by Professors Robert Emmons and Michael McCullough. While sleep was not the focus of the study, they found that individuals who listed the things they were grateful for every day for 21 days slept longer and reported feeling more refreshed upon awakening versus those who did not.
This finding remained relatively unexplored until 2009 when Alex Wood and colleagues took up the investigation as part of their wider research focus on gratitude. They wanted to determine whether the relationship between gratitude and sleep existed independently of the relationship between wider personality traits and sleep, and further investigated how gratitude might bring about benefits to sleep.
Based on evidence that...
Gratitude increases positive thoughts and decreases negative thoughts
Positive pre-sleep thoughts relate to better sleep while negative pre-sleep thoughts impair sleep
...the researchers proposed that gratitude may increase positive pre-sleep thinking and decrease negative pre-sleep thinking, which in turn could benefit sleep.
Indeed, when they analysed their findings, they found that higher levels of gratitude were uniquely related to improved total sleep quality, subjective sleep quality, sleep latency (the time taken to fall asleep), sleep duration and daytime dysfunction, even after controlling for the effects of other personality traits.
Not only this, but they were also right about pre-sleep thoughts - higher levels of gratitude were related to more positive pre-sleep thoughts, which in turn improved subjective sleep quality, sleep duration, sleep latency, and sleep efficiency. Meanwhile lower levels of gratitude were related to more negative pre-sleep thoughts and poorer subjective sleep quality, sleep latency, sleep efficiency and daytime dysfunction.
As well as increasing positive thoughts and decreasing negative thoughts before bed, studies have now shown that the link between gratitude and sleep may also be mediated by:
Higher levels of positive mood
Lower levels of negative mood,
Lower levels of depression and anxiety
Lower levels of stress
Higher levels of adaptive emotion regulation (increased acceptance, positive reappraisal, positive refocusing, refocusing on planning, putting into perspective)
Lower levels of maladaptive emotion regulation (decreased self-blame, other-blame, catastrophising and rumination).
All of these factors may help to reduce the levels of sleep-impairing arousal that make it difficult to fall (and stay) asleep at night.
Many studies have since confirmed the relationship between gratitude and good sleep, and many have used gratitude-based interventions to effectively improve sleep outcomes and reduce insomnia symptoms across a variety of different populations.
Most interventions simply ask individuals to list three things they are grateful for every night before bed (you can read more about gratitude interventions here) - a method that has been shown to improve sleep in as little as one-week with consistent practice.
By increasing gratitude, we are more likely to experience increased positive emotions and thoughts, and decreased negative emotions and thoughts, which in turn may help us to sleep better.
Positive psychology suggests that traits like gratitude can increase the positive emotions and personal resources we need to help buffer and cope with the negative effects of daily stressors and associated levels of pre-sleep arousal.
By focusing on the good things in life and reframing daily events in a positive way, gratitude may begin an upward spiral of benefits that not only helps us to achieve a better night's sleep, but also improves our levels of health and wellbeing more widely.
References
Alkozei, A., Smith, R., Kotzin, M. D., Waugaman, D. L., & Killgore, W. D. (2019). The association between trait gratitude and self-reported sleep quality is mediated by depressive mood state. Behavioral Sleep Medicine, 17(1), 41-48.
Boggiss, A. L., Consedine, N. S., Brenton-Peters, J. M., Hofman, P. L., & Serlachius, A. S. (2020). A systematic review of gratitude interventions: effects on physical health and health behaviors. Journal of Psychosomatic Research, 135, 110165.
Emmons, R. A., & Mccullough, M. E. (2003). Counting blessings versus burdens: An experimental investigation of gratitude and subjective well-being in daily life. Journal of Personality and Social Psychology, 84(2), 377-389.
Heckendorf, H., Lehr, D., Ebert, D. D., & Freund, H. (2019). Efficacy of an internet and app-based gratitude intervention in reducing repetitive negative thinking and mechanisms of change in the intervention's effect on anxiety and depression: results from a randomized controlled trial. Behaviour research and therapy, 119, 103415.
Tout, A. F., Jessop, D. C., Miles, E. (2022, currently unpublished). Exploring the relationships between positive psychology-related traits and sleep: the mediating role of emotion regulation.
Wood, A. M., Joseph, S., Lloyd, J., & Atkins, S. (2009). Gratitude influences sleep through the mechanism of pre-sleep cognitions. Journal of psychosomatic research, 66(1), 43-48.