Many (but by no means all) scientists who study Parkinson's disease say that a disproportionate number of persons with PD are exceptionally intelligent, ambitious, persistent, meticulous and dedicated to their work. These people are much more interested in accomplishment than in transitory diversions and pleasures. They are driven by a desire to achieve something great. Their goals require long apprenticeship and learning periods, high intelligence, dedication and persistence in the face of all kinds of difficulties. Because these personality traits tend to lead to success in many fields of endeavor, you see lots of very accomplished and even famous people who have PD.
There are many scientists who point out that before jumping to conclusions about the idea that "PD leads to eminence and accomplishment" there are many objections that must be addressed. The most important objection is that this premise is based on anecdotal observation -- not clinical data. While clinical impressions are important and must be taken seriously, they are not the same as controlled investigation. In fact, very few controlled studies have been done on the issue. I know of no studies, for example, that have compared the percentages of eminent individuals with PD to the percentages of eminent persons with a similar long term neurologic illness like multiple sclerosis or Huntington’s Disease.
But suppose someone finally does the study and finds that a far greater percentage of persons with PD have publicly recognized accomplishments and achieved something of eminence; perhaps a far greater percentage of the entries in a "Who's Who" from a bygone era (say 50 years ago) are of persons who had had PD, as compared to persons who had some other neurologic illness. Can we then conclude that something about PD facilitates "accomplishment?" Assuming that the people who conducted the study ruled out other obvious explanations (like all the PD persons in the book came from wealthy families or had better access to resources of education, etc) then I would say yes, we are justified in asking whether PD somehow facilitates unusual accomplishment.
How might PD facilitate great accomplishment? The scientists who believe that the link between PD and accomplishment does in fact exist argue something like the following: PD involves a gradual loss of active dopamine in the "short-term reward" centers of the brain, among other centers of the brain. That gradual loss of dopamine tends to over the years make the person shift away from pursuit of short-term awards to pursuit of long-term rewards. Loss of dopamine also tends to make you want to persevere, if not stubbornly so. That tendency seen from another angle yields persistence in the face of punishment and obstacles. Persistence allows you to accomplish some really difficult long-term tasks like election of political office, or obtaining a Ph.D. or writing and publishing a book -- despite repeated rejections or set-backs.
No firm conclusions are yet possible concerning the putative link between PD and eminence. We have to wait on the scientists for this one. When will they perform the appropriate study?
Sources: Horowski R, Horowski L, Calne S, Calne D. From Wilhelm von Humboldt
to Hitler: are prominent people more prone to have Parkinson’s disease? Parkinson Relat Disord 2000;6:205–214.
Jeffrey M. Jones, Great Shakes: Famous People With Parkinson
Disease; Volume 97, Number 12, December 20042004 Southern Medical Association
