People who spend quality time with friends sleep better at night. But those who feel lonely have trouble dozing off, and feel less energetic and less focused the next day. Research at the University of Rochester found that strong friendships reduce stress and anxiety, and make us feel more secure and relaxed. And that reduces activity in the brain area that stays vigilant at night. Basically, if we’re lonely, we feel vulnerable, insecure, and unprotected, even while we sleep, and part of our brain stays on alert for self-protection. So hanging with your friends during the day is your brand new sleeping pill.