If you're down in the dumps, you might just think about watching a funny movie. A new study suggests that the mere expectation of laughter makes us feel good. Researchers split people into two groups. One group was told they'd be watching a funny movie, the other was not. Blood drawn from experimental subjects just before they watched the video had 27 percent more beta-endorphins and 87 percent more human growth hormone, compared to blood from the control group, which didn't anticipate the watching of a humorous video, explained Lee Berk of Loma Linda University. Berk said that combined with prior research into how laughter improves mood, the results would appear to carry important, positive implications for wellness, disease-prevention and most certainly stress-reduction."The study was small, however, involving just 16 people. Levels of these known feel-good substances remained elevated during the video, which brought about what the researchers call "mirthful laughter," and for 12 to 24 hours afterward.