Apart from, you know, those of us who found it did work. Darkness therapy is a key part of it for me. What's the point in taking melatonin if you are then going to destroy its effects by exposing yourself to blue light in the evening? Bright light therapy took me from N24 (a 25 hour day) to DSPS, and then darkness therapy treated the DSPS. Taking melatonin tablets did absolutely nothing for me, presumably because I was sitting in front of a computer in the evening which was suppressing my melatonin levels. Wearing orange glasses which block blue light, on the other hand, works as well as a strong sleeping tablet. I'd far rather try something which normalises natural melatonin production than take artificial melatonin and have to keep compensating for the way light affects the circadian clock. And if you read the reviews of orange glasses on Amazon, you'll find a huge number of people who also find that darkness therapy works, not to mention the research that's out there.