July 2011
Brown
RG, Landau S, Hindle JV, Playfer J, Samuel M, Wilson KC, Hurt CS, Anderson RJ,
Carnell J, Dickinson L, Gibson G, van Schaick R, Sellwood K, Thomas BA, Burn
DJ; for the PROMS-PD Study Group
Background:
Depression and anxiety are common in Parkinson's disease (PD) and
although clinically important remain poorly understood
and managed. To date, research has
tended to treat depression and anxiety as distinct phenomena. There is
growing evidence
for heterogeneity in PD in the motor
and cognitive domains, with implications for pathophysiology and
outcome. Similar heterogeneity
may exist in the domain of
depression and anxiety.
Objective: To identify the main anxiety and depression related subtype(s) in PD and their associated demographic and clinical features.
Methods: A sample of 513 patients with PD received a detailed assessment of depression and anxiety related symptomatology. Latent
Class Analysis (LCA) was used to identify putative depression and anxiety related subtypes.
Results: LCA identified four classes, two interpretable as ‘anxiety related’: one
anxiety alone (22.0%) and the other anxiety coexisting with prominent
depressive symptoms (8.6%). A third subtype (9%) showed a prominent
depressive profile only without significant anxiety. The final class
(60.4%) showed a low probability of prominent affective symptoms. The
validity of the four classes was supported by distinct patterns of
association with important demographic and clinical variables.
Conclusion:
Depression in PD may manifest in two clinical phenotypes, one
‘anxious–depressed’ and the other ‘depressed’. However, a further large
proportion of patients can have relatively isolated anxiety. Further
study of these putative phenotypes may identify important differences in
pathophysiology and other aetiologically important factors and focus
research on developing more targeted and effective treatment.
