One of the greatest Sages of the 20th century, the Chafetz Chaim, writes: "Torah prohibits us from endangering our health. We must be more stringent in these matters than other prohibitions." (see Mishnah Berurah 472:11)
Lack of happiness is dangerous to one's health. A wide range of psychosomatic diseases are caused by emotions like sadness, worry, envy, anger, and anxiety The connection between our emotional and physical health is an idea that is gaining in popularity. The Torah has known this for centuries. As Rabbeinu Yonah (17th century) says in his commentary to Proverbs 17:22: "Happiness will heal a person from illness."
Don't wait to become ill. Increase your level of joy TODAY!
(see Gateway to Happiness, p.25-6)