While the Louvre Museum in Paris prepares to celebrate the 500th anniversary of the death of Leonardo da Vinci, the genius of this artist who produced some of the greatest masterpieces of all time remains somewhat of a mystery. A recent study published in the journal Brain puts forth a new hypothesis to explain his incredible creativity and multitude of unfinished projects: did Leonardo da Vinci have an attention disorder and ADHD?

Painter, sculptor, musician, architect, geologist, mathematician, anatomist, botanist, philosopher… Reading this (non-exhaustive) list, one may wonder how this Florentine, revered by popes and kings alike, managed to excel in so many domains. Marco Catani (a researcher at the Institute of Psychiatry, Psychology and Neuroscience, King’s College, London) and Paolo Mazzarello (Department of Brain Sciences, University of Pavia, Italy) were particularly intrigued by the fact that many of Da Vinci’s creations remained unfinished or only blueprints. For example, specialists say that the Mona Lisa is an unfinished work. The authors evoke ADHD as a possible explanation for Da Vinci's "extraordinary creativity and achievements."

ADHD is a behavioral disorder characterized by ongoing procrastination, an inability to focus on a task, a wandering spirit, impulsiveness, and mental and physical agitation (Demontis et al., 2018). Although it is most commonly recognized in childhood, ADHD is increasingly being diagnosed in adults. In the US, ADHD affects 5% of children and 4.4% of adults.

To support their argument, M. Catani and P. Mazzarello relied on various biographies written on this Renaissance icon and stories about his work habits. All of these documents support their hypothesis. Thus, from childhood, Leonardo is described as a restless child (a fundamental characteristic of ADHD). When he moved to Verrocchio’s study in Florence as a teenager, documents report him as disorganized, spending much time preparing projects he never began. Later, Pope Leo X, who had entrusted him with several missions, noted Da Vinci’s inability to follow through. Other evidence shows he traveled frequently, moving between several activities, and often jumping from one task to another. Like many people with ADHD, Da Vinci slept very little; he was busy day and night, alternating between short cycles of waking and napping.

In addition, there is indirect evidence that Leonardo’s brain and cognitive function was organized differently than most of the population. He suffered a stroke in the left hemisphere at age 65 that left his language skills intact. This would indicate that his language function was predominantly located in the right hemisphere (found in less than 5% of the population). In addition, his notebooks contain mirror spelling and writing errors, which may suggest dyslexia. These combined factors (hemispheric dominance, left-handedness, and dyslexia) are more common in children with neurodevelopmental disorders and ADHD.

Though well-aware of this study’s scientific limitations, Mr. Catani states that: "While impossible to make a post-mortem diagnosis for someone who lived 500 years ago, I am confident that ADHD is the most convincing and scientifically plausible hypothesis to explain Leonardo’s difficulty in finishing his works". Paradoxically, his disorder may well have contributed to his extraordinary creativity. The authors of the article hope that their case study demonstrates that ADHD is not necessarily synonymous with bad behavior or low intelligence, but that it may make it difficult for someone to "capitalize on natural talents."