The relationship between depression and cognitive function in adults with cardiovascular risk: Evidence from a randomised attention-controlled trial
September
The relationship between depression and cognitive function in adults with cardiovascular risk: Evidence from a randomised attention-controlled trial
Haley M. LaMonica 0 1
Daniel J. Biddle 0 1
Sharon L. Naismith 0 1
Ian B. Hickie 0 1
Paul Maruff 0
Nicholas Glozier 0 1
0 Editor: Camillo Gualtieri, North Carolina Neuropsychiatry Clinics , UNITED STATES
1 Brain and Mind Centre, University of Sydney , Camperdown , Australia , 2 Charles Perkins Centre, School of Psychology, University of Sydney , Camperdown , Australia , 3 Central Clinical School, Sydney Medical School, University of Sydney , Camperdown , Australia , 4 Cogstate, Melbourne , Australia
Background and aim This study assessed the association between depressive symptom severity and cognition in middle-to-older aged adults with mild-to-moderate depression and cardiovascular risk factors using an online test battery (CogState) and whether changes in depressive symptoms over 3 months were associated with changes in cognition. Participants (mean age = 57.8) with cardiovascular risk and mild±to-moderate depressive symptoms completed measures of psychomotor speed, learning, and executive function prior to (n = 445)_and after (n = 334) online depression or attention control interventions. The symptom severity-cognition relationship was examined both cross-sectionally and
-
OPEN ACCESS
Data Availability Statement: All relevant data are
within the paper and its Supporting Information
files.
Funding: The trial was supported by the
Cardiovascular Disease and Depression Strategic
Research Program (Award Reference No. G08S
4048 to I.H.) funded by the National Heart
Foundation of Australia and beyondblue: the
national depression initiative. The 45 and Up Study
is managed by The Sax Institute in collaboration
Methods
prospectively.
Results
Limitations
Participants exhibited significantly reduced psychomotor speed and variable impairments
on measures of learning and executive functioning relative to normative data. However,
there was no association of depression severity with cognition at baseline or of change in
depressive symptoms with change in cognitive performance.
Participants were well-educated, which may have protected against cognitive decline.
Attrition may limit generalisability, though is unlikely to explain the lack of association between
depression symptoms and cognition.
with major partner Cancer Council New South
Wales; and partners the National Heart Foundation
of Australia (NSW Division); NSW Health;
beyondblue: the national depression initiative;
Ageing, Disability and Home Care, Department of
Human Services NSW; and UnitingCare Ageing.
Competing interests: Professors Naismith, Hickie,
and Glozier received a grant from beyondblue to
support the conduct of the study. Professor Hickie
served as the Commissioner of the National Mental
Health Commission and was a member of the
Medibank Clinical Reference Group and the Bupa
Australia Medical Advisory Board during this study.
Professor Paul Maruff is a full time employee of
Cogstate. All other authors declare that they have
no conflicts of interest. This does not alter our
adherence to PLOS ONE policies on sharing data
and materials.
Conclusions
Adults with comorbid mild-to-moderate depressive symptoms and cardiovascular risks
performed less well than age-matched normative data on three online cognitive tests; however,
we were unable to show any symptom-cognition association cross-sectionally or
longitudinally, despite significant improvements in depressive symptoms. This challenges the
generalisability of such associations found in more severely unwell clinical samples to those with
a broader depressive symptom profile, or suggests that underlying cardiovascular disease
may account for the association seen in some clinical studies. This has implications for
scaling up selective prevention of cognitive decline.
Introduction
It is recognized widely that Major Depressive Disorder (MDD) is associated with cognitive
dysfunction [1±3] including impaired learning, working memory, processing speed, and
executive functions [4±6]. The neuropsychological profile is, however, heterogeneous and varies
with depressive symptom severity [7, 8], disease subtype [9], age of onset [
10
], etiology,
comorbidities and cerebrovascular disease (CVD) [8]. Regardless of the contributing factors,
cognitive dysfunction in depression is associated with substantial disability and poorer quality
of life [11], and frequently has been suggested as a selective target for interventions aimed at
preventing cognitive decline and subsequent dementia [12].
There are three key issues that might limit such a strategy:
1. Is the depression severity-cognition association present only in the small group with
diagnosed MDD or is it applicable to the much larger group with mild to moderate depression
symptoms?
2. Does improvement in depression result in a significant improvement in cognitive function?
The observed co (...truncated)