Is Morning Light good for mood & stress?

The evidence is still emerging, so it's too early to say for certain. Evidence in this dataset relates mainly to the broader role of light exposure and circadian rhythms in health, including reviews on circadian regulation of metabolism and cardiovascular function, plus more specific research on evening light exposure (e-readers) impairing sleep and light therapy improving insomnia. That's reflected in an evidence score of 32/100 for its role in mood & stress, drawn from 6 studies, with an estimated impact on longevity rated moderate (35/100).