Anxiety and anxious-depression in Parkinson's disease over a 4-year period: a latent transition analysis.
BACKGROUND
Depression and anxiety in Parkinson's disease are common and frequently co-morbid, with significant impact on health outcome. Nevertheless, management is complex and often suboptimal. The existence of clinical subtypes would support stratified approaches in both research and treatment.


METHODS
Five hundred and thirteen patients with Parkinson's disease were assessed annually for up to 4 years. Latent transition analysis (LTA) was used to identify classes that may conform to clinically meaningful subgroups, transitions between those classes over time, and baseline clinical and demographic features that predict common trajectories.


RESULTS
In total, 64.1% of the sample remained in the study at year 4. LTA identified four classes, a 'Psychologically healthy' class (approximately 50%), and three classes associated with psychological distress: one with moderate anxiety alone (approximately 20%), and two with moderate levels of depression plus moderate or severe anxiety. Class membership tended to be stable across years, with only about 15% of individuals transitioning between the healthy class and one of the distress classes. Stable distress was predicted by higher baseline depression and psychiatric history and younger age of onset of Parkinson's disease. Those with younger age of onset were also more likely to become distressed over the course of the study.


CONCLUSIONS
Psychopathology was characterized by relatively stable anxiety or anxious-depression over the 4-year period. Anxiety, with or without depression, appears to be the prominent psychopathological phenotype in Parkinson's disease suggesting a pressing need to understanding its mechanisms and improve management.
Department of Biostatistics,Institute of Psychiatry,Psychology and Neuroscience,King's College London,UK.
S
S
Landau
Department of Biostatistics,Institute of Psychiatry,Psychology and Neuroscience,King's College London,UK.
V
V
Harris
Institute of Neuroscience,Newcastle University,Newcastle upon Tyne,UK.
D J
DJ
Burn
Betsi Cadwaladr University Health Board,Department of Care of the Elderly,Llandudno,UK.
J V
JV
Hindle
School of Health Sciences,City University London,London,UK.
C S
CS
Hurt
Department of Neurology,King's College Hospital,King's Health Partners,London,UK.
M
M
Samuel
EMI Academic Unit,University of Liverpool,St Catherine's Hospital,Wirral,UK.
K C
KC
Wilson
Department of Psychology,Institute of Psychiatry,Psychology and Neuroscience,King's College London,UK.
R G
RG
Brown
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001007:Anxiety / Q000453:epidemiology*; D015897:Comorbidity; D003863:Depression / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000523:psychology*; D011569:Psychiatric Status Rating Scales; D012720:Severity of Illness Index; D006113:United Kingdom / Q000453:epidemiology
Anxiety; Parkinson's disease; depression; latent transition analysis; subtypes