Personality and addictive behaviours in early Parkinson's disease and REM sleep behaviour disorder.
Changes in personality have been described in Parkinson's disease (PD), with suggestion that those with established disease tend to be risk averse with a disinclination for addictive behaviour. However, little is known about the earliest and prodromal stages. Personality and its relationship with addictive behaviours can help answer important questions about the mechanisms underlying PD and addiction.



941 population-ascertained PD subjects within 3.5 years of diagnosis, 128 patients with rapid eye movement sleep behaviour disorder (RBD) and 292 control subjects were fully characterised for motor symptoms, non-motor symptoms and across the following 5 personality domains: 1) neuroticism 2) extraversion 3) conscientiousness 4) agreeableness 5) openness using the Big Five Inventory.



Patients with early PD were more neurotic (p < 0.001), less extraverted (p < 0.001) and less open than controls (p < 0.001). RBD subjects showed the same pattern of being more neurotic (p < 0.001), less extraverted (p = 0.03) and less open (p < 0.001). PD patients had smoked less (p = 0.02) and drunk less alcohol (p = 0.03) than controls, but caffeine beverage consumption was similar. Being more extraverted (p < 0.001), more open (p < 0.001), and less neurotic (p < 0.001) predicted higher alcohol use, while being more extravert (p = 0.007) and less agreeable (p < 0.001) was associated with smoking more.



A similar pattern of personality changes is seen in PD and RBD compared to a control population. Personality characteristics were associated with addictive behaviours, suggestive of a common link, but the lower rates of addictive behaviours before and after the onset of motor symptoms in PD persisted after accounting for personality.
Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
Fahd
F
Baig
School of Social and Community Medicine, University of Bristol, Bristol, UK.
Michael A
MA
Lawton
Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
Michal
M
Rolinski
Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
Claudio
C
Ruffmann
Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
Johannes C
JC
Klein
Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Department of Neurology, Northampton General Hospital NHS Trust, Northampton, UK.
Kannan
K
Nithi
Psychological Medicine Service, Oxford University Hospitals NHS Trust, Oxford, UK.
David
D
Okai
Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; School of Social and Community Medicine, University of Bristol, Bristol, UK.
Yoav
Y
Ben-Shlomo
Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK. Electronic address: michele.hu@ndcn.ox.ac.uk.
Michele T M
MT
Hu
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016739:Behavior, Addictive / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications* / Q000523:psychology*; D010551:Personality; D010552:Personality Assessment; D010554:Personality Disorders / Q000150:complications*; D020187:REM Sleep Behavior Disorder / Q000150:complications* / Q000523:psychology*; D012720:Severity of Illness Index
Addiction; Parkinson's disease; Personality; REM sleep behaviour disorder; Smoking