Laughter therapy has also been shown to improve anxiety in patients with Parkinson’s disease , reduce anxiety and depression in nursing students, and improve optimism, self-esteem, and depression in menopausal women. From a general psychological perspective, author Bernard Saper suggests in a paper for Psychiatric Quarterly that the ability to maintain a sense of humor and the ability to laugh can act as positive coping mechanisms to help a person get through difficult times.

Twice a week, participants engaged in group “laughter dance routines” and some light breast massage while inducing laughter. Mothers who participated in the laughter therapy saw a small increase in their IgA. However, even a small amount was significant to the researchers, given that the postpartum period is when natural IgA in breast milk declines (it is at its highest level right after delivery, in the earliest, nutrient-dense breast milk known as colostrum). Another study with college students found that watching funny movies increases salivary IgA (sIgA). Researchers have also found small examples of laughter’s ability to increase the body’s natural killer cells (NKs), a type of lymphocyte that is easy to test for in the blood. One study in the American Journal of Medical Science, albeit small—a cohort of only 10 male subjects—found significantly increased NK cell activity in the experimental group. Additional studies have shown increases in NK cell activity after laughter therapy or humorous videos, but most of these studies were done on male subjects.

The laugher therapy, which the subjects undertook over eight sessions, for 40 minutes twice a week, included “singing funny songs, laughing for diversion, stretching, playing with hands and dance routines, laughing exercises, healthy clapping, and laughing aloud.” The results showed reduced depression and general mood improvement as well as improved sleep in the experiment group compared to the control group. Another study in the Journal of Alternative and Complementary Medicine found that three 60-minute laughter therapy sessions improved the depression and negative mood states of cancer patients.

Laughter is good for your cardiovascular system. Your lungs aren’t the only organ that benefits from a great guffaw. A study in Medical Hypotheses found powerful benefits to the heart and cardiovascular system. Study participants watched either a comedy like Saturday Night Live or the bleak opening sequence of Saving Private Ryan, which is known to increase mental stress. They used a technique called brachial artery reactivity testing (BART), a form of ultrasound that looks at the brachial artery. Participants who watched the stressful movie experienced a 35 percent reduction in flow-mediated vasodilation (FMD, or how blood vessels dilate and contract); sluggish FMD is a risk factor for atherosclerosis. Meanwhile, the group that watched the funny scene saw a 22 percent increase in FMD, comparable to exercise. In short, laughing helped their blood flow better. The American Heart Association recommends laughter for a healthy heart, adding that research has shown laughter promotes reduced artery inflammation and increased production of HDL, or “good” cholesterol.

Social laughter can relieve pain. Laughter might be as good as some analgesics for pain, something early physicians seemed to understand. In the 14th century, French surgeon Henri de Mondeville used humor to distract patients from the pain of surgery and to help them during recovery. More modern research has found that participants who watched comedy videos needed less pain medication than those who watched control videos. In a 2011 study published in the Proceedings of the Royal Society, over the course of six experiments using extreme cold as a pain-tolerance measure, researchers found that social laughter laughter done in groups in a social context—elevates pain thresholds. The authors suggest, “These results can best be explained by the action of endorphins released by laughter.”

I’m sick of following my dreams, man. I’m just going to ask where they’re going and hook up with ’em later. 😩😆😂