A quick Google confirms this: they use either an identical-looking light with a different response, or a different light altogether. &quot;Here&#x27;s a light, here&#x27;s a sugar pill, log your mood please...&quot;<p>As silly as that all sounds, it&#x27;s already a million times better than what this guy did. He took the &quot;if a little is ineffective a LOT will be better&quot; approach and built a damn lighthouse in his living room. And if the goal is a DIY project and a blog post, OF COURSE you&#x27;ll feel better after &quot;your treatment.&quot; It&#x27;s approaching group therapy at that point. There&#x27;s a lot of this crap on HN lately.