In answer to a question on Parenting.SE about helping a child cope with night terrors, a user posted:
Here's what you do For the little guy. For his night terrors give him 1 to 2 small square of dark chocolate candy 2 to 3 hours before bedtime every night. Believe me this works it's stops the trigger of any night terrors from happening. Now remember it must be dark chocolate candy Of high grade percentage. His fears will stop once his night terrors are gone. I encourage all parents with children that have night terrors to try dark chocolate. It's cheap and it works. Remember this is a daily regiment before bedtime. If you stop the daily regiment the night terrors will come back again. Give it a shot help your kids.
As proposed remedies go this one seems pretty harmless, but it's nice to have researched, evidence-based answers (especially for a claim that is so completely effective).
All I can find with a web search is anecdotal evidence, typically comments left on forums or blog posts (here, here). (Some say it's Hershey's special dark, others don't mention a brand, just "dark chocolate".) There is a YouTube video which also suggests cocoa powder for diabetics. Most say it should be used regularly before sleeping, one says to give it when a child wakes up.
Is there any research suggesting dark chocolate is a useful treatment for night terrors?