I’ve come across conjecture that a certain type of person is more likely to develop Parkinson’s a number of times now, most recently in the film about Barbara Thompson described in my last post. Barbara’s consultant suggested that people who are in some way driven or obsessed were more likely to get Parkinson’s. Other, vaguer, sources have suggested that Parkies are inherently more intelligent than average.
So I decided to do a quick survey of the literature (or, rather, the abstracts available on the Web). You can skip the details and go straight to the summary if you wish.
A 1993 article in Neurology suggested that we weren’t thrill-seekers:
Studies suggest that Parkinson’s disease (PD) is associated with a particular group of personality characteristics. With relative uniformity, PD patients are described as industrious, rigidly moral, stoic, serious, and nonimpulsive.
[… The study was based on a personality questionnaire which uncovered a low tendency towards ‘novelty seeking’ among people with Parkinson’s …]
Patients with low novelty seeking are described as being reflective, rigid, stoic, slow-tempered, frugal, orderly, and persistent, characteristics similar to those in the clinical description of PD patients. We review evidence supporting the claim that novelty seeking is dopamine-dependent, and suggest that damage to the mesolimbic dopaminergic system causes the described personality profile of PD patients.
But that is (theoretically) an effect of the condition. What about before Parkinson’s manifested itself?
The medical term for “preceding the symptoms of disease or disorder” is premorbid. This term appears in a number of abstracts, from which I gleaned a fairly consistent general description of potential Parkies as rather reserved, upright types. Rather like the postmorbid description, in fact.
One paper – from 1983 – was more forthcoming. In common with several other studies, the researchers used a personality test to attempt to establish the personality of a small sample of patients:
The results obtained suggest that parkinsonian patients are of an introverted and anancastic premorbid personality type. In the [personality test] marked trends toward “overcontrol”; “depressiveness”, “positive social resonance”, and “social impotency” were observed. The results are discussed and related to findings of distinctive premorbid smoking and drinking habits of parkinsonian patients.
“Premorbid personality of Parkinson patients”
Poewe W, Gerstenbrand F, Ransmayr G, Plörer S
Journal of Neural Transmission. Supplementum [1983, 19:215-24]
Anancastic means “pertaining to any form of repetitious stereotyped behaviour that causes anxiety if prevented” and is often used to describe obsessive behaviour. This may be where Ms. Thompson’s consultant got his “driven personalities” from.
I am not sure what the following study actually consisted of, because the abstract – reproduced in full below – does not actually say. However, I imagine it to have been a review of the literature.
For decades clinicians have postulated a characteristic preexisting personality in patients who develop Parkinson’s disease (PD). They are described as moralistic, law-abiding, conscientious, and averse to risk-taking. The limited personality surveys tend to be confirmatory, but most of the literature is anecdotal or replete with unprovable psychodynamic postulates. In addition to an apparent stability of marriages and lack of alcoholism, patients with PD are less likely than controls to be smokers. It has been suggested that nicotine and its byproducts are not actually protective against PD, and it could be postulated that higher-than-average intrinsic dopamine may facilitate addiction. Smoking for the patient who is later to develop PD may be particularly unrewarding. In addition, the postulated personality for PD may predispose to hard work, perspiration, and increased exposure to putative trace elements in the water supply.
I did find a review from 2006 of past literature, all of which was, apparently, found lacking in some way.
Rigid and introverted personality type has been suggested as possibly associated with risk of Parkinson’s disease (PD). However, to be a risk, the measurement of personality must precede the onset of PD, more than simply reported as personality in PD cases. Several reviews have been published examining the literature base for this suggestion; however, the issue of “premorbid” personality measurement was not emphasized. […] No articles met all selection criteria. Four articles met most selection criteria and three of them reported significant differences in personality features said to be present before PD onset and between PD cases and controls. PD cases were more introverted, cautious, socially alert, and tense than controls. […] the general descriptions of PD patients included nervous, cautious, rigid, and conventional. There do appear to be parkinsonian characteristics, but these studies were all retrospective. To confirm that personality traits precede PD onset and are a risk for this condition, prospective research is required. Even then, the term “premorbid” is difficult to define due to the unknown latent period before onset of PD. Additional research would involve correlating personality characteristics to activities or changes in the brain.
© 2006 Movement Disorder Society
It is difficult to imagine how any study could determine premorbid personality without recourse to retrospective methods. The study noted below used a retrospective questionnaire to try to establish personality differences between pairs of twins – one of whom had Parkinson’s, one of whom didn’t. They found:
[…] During premorbid times the affected twin with later Parkinson’s disease was estimated to have been “less often the leader” in the twin pair.
Although small in sample size, this twin study indicates a genetic impact for some personality features beyond the Parkinson’s disease motor syndrome.
“Personality, depression, and premorbid lifestyle in twin pairs discordant for Parkinson’s disease”
Ilse Heberleina, Hans-Peter Ludinb, Joachim Scholza, Peter Vieregge
J Neurol Neurosurg Psychiatry 1998;64:262-266 doi:10.1136/jnnp.64.2.262
I still marvel at the ability of researchers to locate convenient pairs of twins.
Another review, this time with a mercifully brief abstract:
A review of the extensive descriptive literature suggests that many Parkinsonian patients exhibit an emotional and attitudinal inflexibility, a lack of affect and a predisposition to depressive illness, which may antecede the development of motor abnormalities by several decades. Introspective, over-controlled, anhedonic personality traits together with suppressed aggresivity are frequently found. It is unclear whether these behavioural patterns are relevant aetiological factors or prodromal symptoms of the disease.
“The pre-morbid personality of patients with Parkinson’s disease”
C J Todes, A J Lees
J Neurol Neurosurg Psychiatry 1985;48:97-100 doi:10.1136/jnnp.48.2.97
Quite right: it is difficult to determine cause from effect in these cases. And is that Cecil Todes popping up as an author, there?
It occurred to me to wonder if anyone had done any research specific to the premorbid personalities of Young-Onset Parkies. After all, if there is a personality type more at risk of developing Parkinson’s, you might imagine that such people might develop the condition earlier. I couldn’t find anything apart from a note that there were “no differences in the […] personality characteristics” between young and old onset in an article entitled “A comparison of clinical and pathological features of young‐ and old‐onset Parkinson’s disease”. The article did not seem concerned with any premorbid characteristics.
Finally, I tried to find the source of the suggestion that us Parkies are inherently more intelligent than average. There didn’t seem to be any research in this area; most of the articles that I found discussed cognitive impairments caused by Parkinson’s.
There may be a pre-Parkinsonian personality. It seems that people have gone looking for it, and found one (which is, in itself, highly suspicious) – but nobody is quite sure whether these personality traits are indicative of a likelihood of developing Parkinson’s or an early symptom. As Parkinson’s is generally deemed to have been present up to 10 years before diagnosis, it may be difficult to ascertain whether the common traits were genuine aspects of an individual’s personality or whether they were imposed by the beginning of a decline in dopamine.
If there truly is a pre-Parkinson’s personality (i.e. one that indicates an increased risk factor of the condition), then it is typified by a number of traits that seem to describe a reserved, well-behaved type with a tendency to depression and possible obsessive behaviour (the illustration shows a selection of words used to describe the personality type).
I fit some of that description, but not all of it. I do not believe that my personality has changed appreciably within the last 10 years or more (so I don’t think my personality has been affected by the condition). I have to say, though, that I’m not entirely convinced by the idea that there might be a pre-Parkinson’s personality.
I would be very interested to hear whether other Parkies feel that they fit the description – please leave a comment if you are happy to share your feelings on this!