The use of light for therapeutic purposes dates back millennia. Light therapy, as a possible treatment for seasonal affective disorders, was first identified in the mid-1980s. In modern psychiatry, bright light therapy has also been shown to be effective and safe for the treatment of non-seasonal major depressive disorder.1 Large-scale cohort analyses showing that both daytime and night-time light exposure are associated with psychiatric diseases reinforce the importance of light for mental health2 and have led to a renewed consideration of the impact of lighting in the urban environment on human health.3 Despite the increasing evidence that lighting has profound and widespread impacts on health and functioning, there remains a notable gap in our understanding of the mechanisms and features of effective light therapy strategies for mood disorders, prompting further in-lab research in humans.
The reproducibility of research findings, and therefore the reliability…
