Parkinson's disease motor subtypes and mood§

Authors


  • Funding agencies: The work reported here was supported by Parkinson's UK (grant number J-0601). Research support was also received from the UK Department of Health via the National Institute for Health Research (NIHR) Specialist Biomedical Research Centre for Mental Health award to South London and Maudsley NHS Foundation Trust (SLaM) and the Institute of Psychiatry at King's College London; the NIHR Dementias and Neurodegenerative Diseases Research Network (DeNDRoN), and the Wales Dementias and Neurodegenerative Diseases Research Network (NEURODEM Cymru).

  • Relevant conflicts of interest/financial disclosures: Nothing to report.

  • §

    Full financial disclosures and author roles may be found in the online version of this article.

  • Members of the PROMS-PD Study Group who contributed to this work are listed in the Appendix.

Abstract

Parkinson's disease is heterogeneous, both in terms of motor symptoms and mood. Identifying associations between phenotypic variants of motor and mood subtypes may provide clues to understand mechanisms underlying mood disorder and symptoms in Parkinson's disease. A total of 513 patients were assessed using the Hospital Anxiety and Depression Scale, and separately classified into anxious, depressed, and anxious-depressed mood classes based on latent class analysis of a semistructured interview. Motor subtypes assessed related to age-of-onset, rate of progression, presence of motor fluctuations, lateralization of motor symptoms, tremor dominance, and the presence of postural instability and gait symptoms and falls. The directions of observed associations tended to support previous findings with the exception of lateralization of symptoms, for which there were no consistent or significant results. Regression models examining a range of motor subtypes together indicated increased risk of anxiety in patients with younger age-of-onset and motor fluctuations. In contrast, depression was most strongly related to axial motor symptoms. Different risk factors were observed for depressed patients with and without anxiety, suggesting heterogeneity within Parkinson's disease depression. Such association data may suggest possible underlying common risk factors for motor subtype and mood. Combined with convergent evidence from other sources, possible mechanisms may include cholinergic system damage and white matter changes contributing to non-anxious depression in Parkinson's disease, while situational factors related to threat and unpredictability may contribute to the exacerbation and maintenance of anxiety in susceptible individuals. © 2011 Movement Disorder Society

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