A longitudinal study found correlations between more time spent in natural daylight and improved mood, sleep, and circadian functions in a sample of over 400,000 participants from the UK Biobank biomedical database. Participants spent an average of 2.5 hours per day outdoors, and every additional hour spent in natural light had a positive impact on mental health and sleep quality. The authors suggest that light therapy, which strengthens the circadian rhythm, could be an effective part of the treatment for depressive disorders. In buildings with limited access to natural light during the day, high-quality biologically optimized artificial lighting can serve as a fully functional alternative.
Spending more time in daylight is linked to improved mental health
Each added hour spent in daylight was associated with a lower likelihood of developing a depressive disorder and having to take antidepressants, lower neuroticism, and greater feelings of satisfaction and happiness, independent of demographic, lifestyle or occupational factors.
Spending time in daylight can be a supportive means to better sleep
Each added hour of daylight correlated with greater ease getting up, less frequent fatigue, fewer symptoms of insomnia and better synchronisation with the social time.
