(Part of the foundation for a case I’m making about biological foundations of ADHD. The “Parkinsonian personality” is well known and the opposite of classic ADHD. ADHD is strongly linked with much higher than normal numbers of dopamine transfer neurons in specific parts of the brain and Parkinson’s disease is directly connected to the death of these neurons.)
The Parkinsonian Personality: More Than Just a “Trait”
Since 1913 patients with Parkinson’s disease (PD) have been described as particularly industrious, devoted to hard work, inflexible, punctual, cautious, and moralist (1). These psychological characteristics have been so constantly reported that the concept of “Parkinsonian personality” emerged. In this regards, in the last few years PD patients have been evaluated according to several models of personality assessment (2), with the Big Five Model (BFM) (3) and the Cloninger’s Psychobiological Model (CPM) (4) as the most used. Studies following the BFM reported that PD patients presented high levels of Neuroticism and low levels of both Openness and Extraversion (5, 6), while studies using the CPM described the temperament of PD patients as characterized by low Novelty Seeking (NS) and high Harm Avoidance (HA) (2, 7, 8). As a matter of fact, the high HA could be responsible for the Parkinsonians’ tendency to be cautious, fearful, pessimistic and shy, while the low levels of NS could account for the tendency to be unsocial, frugal and orderly. Under different points of view, the “Parkinsonian personality,” as it has been consistently reported in literature (7, 9), shares several clinical features with the obsessive-compulsive personality disorder (OCPeD) as classified in the Diagnostic and Statistical Manual for Mental Disorders (DSM) (10).
The OCPeD is defined as a “chronic, pervasive, maladaptive pattern of preoccupation with orderliness, perfectionism, mental and interpersonal control at the expense of flexibility, openness, and efficiency” (10). In the general population, it is the most common personality disorder with a lifetime prevalence reaching the 9.3% (11). Classically considered as stable over time, an increasing number of observations allow to hypothesize that the clinical presentation of OCPeD is less stable than originally assumed, being possible to detect the occurrence, attenuation, or relapse of obsessive symptoms across the life-time (12, 13). While the correspondence between the presence of high HA and low NS levels and OCPeD has been investigated in the general population over the years (14–16), no studies on the correspondence between these temperament traits, configuring the parkinsonian personality, and OCPeD have been conducted in PD patients.