SUFFERING from writer’s block? Try sniffing rotting apples.

This seemed to work for the 18th-century poet Friedrich Schiller, who kept the decaying fruit in his study because he felt the scent stimulated creativity. Though Goethe thought this a little nutty, a couple of hundred years later the University of Arizona psychologist Gary Schwartz found that Schiller might have been on to something. The scent of spiced apples, Prof. Schwartz discovered, significantly lowered the blood pressure of test subjects.

The therapeutic properties of scent have been cultivated since antiquity. They were a particular fascination of medieval monks in their cloistered gardens. Now modern science is revealing the wisdom of ancient practices.

In 2009, medical researchers at Tottori University in Japan found that exposing Alzheimer’s patients to rosemary and lemon in the morning and lavender and orange in the evening resulted in improved cognitive functions. A 2006 study by researchers at the New York University Medical Center discovered that postoperative patients exposed to the smell of lavender reported a higher satisfaction rate with pain control. And a 2007 study in the Journal of Clinical Oncology reported that cancer patients who received massage with aromatic oils experienced a significant improvement in anxiety and depression.

By contrast, last year researchers at the University of Dresden Medical School in Germany found that people without a sense of smell — anosmics, they’re called — generally were more socially insecure and had a higher risk of depression.