The spectrum of neuropsychiatric symptoms in patients with early untreated Parkinson’s disease
- D Aarsland1,2,3,
- K Brønnick1,
- G Alves1,4,
- O B Tysnes3,5,
- K F Pedersen1,4,
- U Ehrt1,2,
- J P Larsen1,3,4
- 1The Norwegian Centre for Movement Disorders, Stavanger University Hospital, Stavanger, Norway
- 2Department of Psychiatry, Stavanger University Hospital, Stavanger, Norway
- 3Institute of Clinical Medicine, School of Medicine, University of Bergen, Bergen, Norway
- 4Department of Neurology, Stavanger University Hospital, Stavanger, Norway
- 5Department of Neurology, Haukeland University Hospital, Bergen, Norway
- Professor D Aarsland, Stavanger University Hospital, The Norwegian Centre for Movement Disorders, PO Box 8100, 4068 Stavanger, Norway;
- Received 13 November 2008
- Revised 26 January 2009
- Accepted 27 January 2009
Background: Neuropsychiatric symptoms are common in Parkinson’s disease (PD) and have important clinical consequences for patients, caregivers and society. Few studies of neuropsychiatric symptoms in early untreated PD exist.
Objective: To explore the range, clustering and correlates of neuropsychiatric symptoms in an incidence cohort of untreated subjects with PD.
Methods: All cases with incident PD identified during a 22 month period in four counties of Western and Southern Norway were included. Standardised criteria were used to diagnose PD. The Neuropsychiatric Inventory (NPI) was administered to 175 PD and 166 healthy control subjects with similar age and sex distributions. Cluster analysis was used to investigate the interrelationship of NPI items.
Results: The proportion with any NPI symptoms was higher in PD (56%) than in controls (22%) (p<0.001). Depression (37%), apathy (27%), sleep disturbance (18%) and anxiety (17%) were the most common symptoms. Clinically significant symptoms occurred in 27% of the PD group compared with only 3% in the control group (p<.001). Subjects with clinically significant neuropsychiatric symptoms had more severe parkinsonism than those without. Two neuropsychiatric clusters were identified, one characterised by mood symptoms and one by apathy.
Conclusions: Although the majority of patients with early untreated PD do not have clinical significant neuropsychiatric symptoms, these symptoms are more common in patients than in people without PD. Both psychological stress and brain changes associated with PD are likely to contribute to the higher frequencies.
See Editorial Commentary, p 830
Funding: This study was funded by the Western Norway Regional Health Authority (grant No 911218) and the Research Council of Norway (grant No 177966).
Competing interests: None.
Ethics approval: The study was approved by the Regional Committee for Medical and Health Research Ethics, Western Norway, University of Bergen, Bergen, Norway.