By Dr. Brian McDonough, Medical Editor

PHILADELPHIA (CBS) – It is called the placebo effect. Giving a substitute for medicine…often something that looks like medicine to see if it improves someone’s health.

Now a report from the journal Pediatrics suggests the placebo effect could have a real impact with a common childhood problem – the cough.

Penn State researchers looked at 120 children between 2 and 47 months old, with a cough that had lasted fewer than seven days.

There were three groups: one was given a placebo of sweet-tasting nectar, one given a placebo of water with food coloring, and one getting no treatment at all.

While there was no difference in results between the agave group and the food coloring group, both groups fared better than the “no treatment” group.

These kids showed improvement in cough frequency, cough severity, congestion severity, and cough effect on child and parent sleep.

Cough is one of the most common reasons for visits to the doctor.