Drugs taken to fight Parkinson’s disease may have a beneficial side effect – a study by Israeli researchers confirms that patients taking particular medicines tend to be more artistic.

The study appears to narrow down the reason to elevated dopamine levels in the brain. It’s the first hard evidence of such a link, though anecdotal connections have been out there for years, even centuries.

Published in the journal Annals of Neurology in June, the small, case-control study shows that Parkinson’s disease patients who are taking drugs to boost dopamine activity in the brain are more verbally and visually creative than their healthy peers – and increased dosage is linked with greater creativity. The findings could help improve quality of life for people with the disease.

“We know that [19th-century artist Vincent] Van Gogh had psychotic spells, in which high levels of dopamine are secreted in the brain, and he was able to paint masterpieces during these spells — so we know there is a strong relationship between creativity and dopamine,” said Dr. Rivka Inzelberg, a neurologist at Tel Aviv University and Sheba Medical Center, Tel Hashomer, one of the study’s authors.

There have long been stories of Parkinson’s disease patients – famous examples of whom are actor Michael J. Fox and boxer Mohammed Ali – developing new artistic talents, like painting, sculpting and writing. In a 2012 study, Inzelberg reviewed the medical literature on the phenomenon and discovered that the reported cases had one thing in common: The patients were all being treated with drugs to increase dopamine activity.

The drugs – dopamine precursors and dopamine receptor agonists – are prescribed to most Parkinson’s patients to compensate for the death of dopamine-generating cells in the brain, causing the tremors and other motor problems characteristic of the disease. Mental problems can develop as the disease progresses.

“[The 2012 study] began with my observation that Parkinson’s patients have a special interest in art and have creative hobbies incompatible with their physical limitations,” Inzelberg said. “In my present research, we conducted the first comprehensive study to measure the creative thinking of Parkinson’s patients. This was not a simple task, because how does one measure, or quantify, creativity? We had to think creatively ourselves.”

In the study, the first empirical research on creativity in Parkinson’s patients, Inzelberg and a team of Israeli researchers ran four tests on 27 patients being treated with the dopamine-boosting drugs. Participants were tested on their ability to provide a word related to three other given words, to interpret images and questions with originality, to understand novel metaphors and to list as many words as they could that belonged to a given category and started with a given letter (for instance, fruits starting with “p”).

Across the range of tests, Parkinson’s disease patients gave more original and thoughtful answers than 27 controls of similar age and education level. Significantly, when divided into two groups based on how much medication they were taking, the more-medicated patients performed better on the tests. Using a questionnaire, the researchers also ruled out the theory that creativity in Parkinson’s disease patients is related to compulsions, like addictive gambling and hoarding, which patients often develop.

The results indicate a connection between dopamine and creativity, though it is too soon to say how it works. For now, Inzelberg hopes her research will increase appreciation of the artistic abilities of Parkinson’s disease patients, encouraging them to use their art to cope with the often-isolating disease – and generating funding for more research.