Interesting reference, I'll read that article for sure, JAMA Psychiatry is a top-tier journal. However not a new idea, there have been prior studies showing be

Interesting reference, I'll read that article for sure, JAMA Psychiatry is a top-tier journal. However not a new idea, there have been prior studies showing benefit of light treatment for non-seasonal depression, particularly in "elderly" individuals (e.g., people over 60). How it works in practice, well, the usual caveat about varying mileage definitely applies in this domain. I've recommended adjunctive light treatment over many years. Though it can help reduce symptoms, in most cases other therapies are still necessary to achieve remission of depression. Several comments were made about the lamps used for light treatment. The optimum emission spectrum for light therapy is really an unsettled question. Early on (in 1980's) the quantity of light was emphasized, 10000 lux is considered standard since that is equivalent to minimal "normal" daylight, e.g., heavily overcast midday sky in late fall. Some work suggests as little as 4-5K lux may be sufficient for response. Some studies have shown blue light (say ~460nm) to be most effective, others found peak response to green (~500-550). And some researchers in the field have the opinion the spectral quality is less important the light intensity. Since usually light treatment for depression is administered in early morning, consistent with normal circadian influence, the blueness of light as encouraging wakefulness is not a problem. As some comments noted, some research suggests blue light exposure in evening hours can trigger wakefulness, though not yet enough evidence to say that's been proven. Notably device displays have been getting brighter, and more blue, thanks to "white" LED illumination which has prominent emission ~450nm. Of course LED output spectrum varies across diodes, but kind of a parallel to fluorescent lamps which tend to have prominent green emission regardless of apparent "warm" or "cool" effect. The advice to avoid computer or phone use in evening is based on both brightness and spectrum, to say nothing of the mentally stimulating effects interfering with sleep onset.