It was 1988 when Bobby McFerrin’s a cappella croon “Don’t Worry, Be Happy” became the first in that genre to reach Number One on the Billboard Hot 100 chart. The same year, the drug maker Allergan bought the rights to ophthalmologist Dr. Alan Scott’s innovative use of an injectable toxin to control uncontrollable blinking and crossed eyes, a partnership that helped to push the toxin through the regulatory approval process. One year later, in 1989, the FDA approved the drug and Allergan renamed it BOTOX.

It would be another 10 years before BOTOX would be used cosmetically, injected under the skin’s surface into the muscle tissue below effectively relaxing the muscle and eliminating the contractions that caused wrinkles-on the forehead, between the brows and around the eyes.

In the 30 years since its introduction, sales of Botox have soared with Botox injections being the most popular treatment over all other cosmetic options. Even in a recessionary economy, American’s spent $329 million on Botox in 2008, a 3% drop from 2007, but according to the New York Times, still not as great a drop as breast implants that dropped 12% in the same time period.

But just like McFerrin’s lyrics, Botox is proving to make people happy. The Canadian Globe and Mail reported in early April that studies conducted by Michael Lewis, an experimental psychologist from Wales, showed that the women in the test group who received Botox injections were significantly less anxious and depressed than did their peers who were not injected with BOTOX.

“The point is that by looking less anxious and depressed, patients are less anxious and depressed,” says Dr. Raval.

Tralee Pearce filed the story entitled “Botox: A shot at happiness,” citing scientific research dating back as far as Charles Darwin who theorized that the act of frowning can make an individual unhappier and conversely the act of smiling can make a person happier. Darwin called his postulation “facial feedback.”

“Public speaking guru Dale Carnegie promoted a similar theory,” Jeffrey R. Raval, MD, FACS, says. “Extend a smile; get one in return…the entire world is a lot more likeable. We see it all the time.”

Psychologists have an analogy they use to explain the phenomenon. “You are a mirror” describes in layman’s terms what actually takes place in scientific testing of facial images. “You attract what you radiate,” is the way advice columnists on dating websites like eHarmony and Match sum it up. The nuances in facial expression and body language communicate a person’s state of mind and serve to either make them more attractive or, in the case of a scowling countenance, repel others-consistent with Darwin and Carnegie’s theories.

Don’t worry, be happy. And while you’re at it, get BOTOX.