Prevalence of cognitive impairment in major depression and bipolar disorder
Cognitive impairment refers to problems with brain functions such as memory, planning, organisation, and processing speed. Cognitive impairment is considered a core feature of mood disorders; namely, major depressive disorder and bipolar disorder. Most research to date has investigated cognitive impairment in depressed samples as a whole (i.e., looking at average scores across a group) which can mean that details about the extent of cognitive impairment, if any, for each person is lost.
This new study — published in the journal Bipolar Disorders — aimed to determine the proportion of patients with mood disorders who would actually be considered as ‘cognitively impaired’. We addressed this issue by looking at four different samples of people with mood disorders (two samples with bipolar disorder, and two samples with a mixture of bipolar and major depressive disorder), and applying four definitions to categorise individuals as being cognitively impaired. Findings showed that the percentage of individuals classed as cognitively impaired differed greatly depending on the definition used. Importantly, we also found that when taking into account an estimate of each patient’s level of cognitive ability prior to developing a mood disorder, the percentage of patients categorised as cognitively impaired increased significantly in some samples.
There are many important implications from the findings of this study. There appears to be a significant portion of people with mood disorders who are not considered to be cognitively impaired. A minority of patients, particularly with more severe depression, have substantial cognitive impairment. Thus, in treatment studies of mood disorders that are aiming to directly improve cognitive impairment (e.g., cognitive remediation), there may only be a subset of patients who would benefit. Deciding on a standard definition to categorise cognitive impairment is necessary, given the variability in rates of cognitive impairment with different definitions. Last, it may be of more use to compare patients’ cognitive abilities with an estimate of their previous level of cognitive functioning (rather than ‘healthy’ individuals) as that would provide a more meaningful picture of impairment for each patient.
Citation: Douglas KM, Gallagher P, Robinson LJ, Carter JD, McIntosh VVW, Frampton CM, Watson S, Young AH, Ferrier IN, Porter RJ (in press). Prevalence of cognitive impairment in major depression and bipolar disorder. Bipolar Disorders (advance online publication) doi: 10.1111/bdi.12602
EMCR Committee Members
Dr Tamsyn Van Rheenen — Co-chair
Dr Tamsyn Van Rheenen is a post-doctoral research fellow working in the area of cognitive neuropsychiatry. Her research aims to use an understanding of neurobehavioral function and neurobiology to discover and validate biomarkers, improve diagnostic accuracy/risk identification and inform the development of novel treatment interventions for bipolar disorder.
Tamsyn graduated from Swinburne University in 2009 with a Bachelor of Social Science succeeded by an honours degree in Psychology. She commenced her PhD at Swinburne University in April 2010, after receiving an Australian Postgraduate Award to complete her research into cognition and emotion processing in bipolar disorder. Her thesis was passed in March 2014.
Tamsyn has recently been awarded a Peter Doherty Biomedical early career research fellowship from the NHMRC. She has also been the recipient of substantial travel funding to support her to present her work at several national and international conferences. The research she has been involved with has been featured in the in various news outlets (e.g., Medwire News, ABC Science, Nature World News, Psychiatry Weekly) and she has been recognized with several prestigious awards including an Australian Schizophrenia Conference Young Investigator Award for Research Excellence and a 2014 Australian Psychological Society Award for Excellent PhD thesis in Psychology.
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Dr Katie Douglas — Co-chair | NZ representative
Dr Katie Douglas is a Research Fellow at the Department of Psychological Medicine, University of Otago, in Christchurch, New Zealand. Her research interests relate to the cognitive, psychological and neurobiological aspects of mood and anxiety disorders, factors influencing response to psychotherapy and pharmacotherapy, and treatments aimed at improving cognitive and functional outcomes in mood disorders. She supervises PhD students in the areas of cognitive functioning in mood disorders, elderly depression and polycystic ovarian syndrome. Katie is a registered Clinical Psychologist and her clinical practice currently involves providing psychological therapy in clinical trials at the Department of Psychological Medicine for patients with mood disorders. She has previously worked clinically in the areas of health psychology and forensic psychology.
Katie has been awarded two major research grants as Principal Investigator from the Canterbury Medical Research Foundation. The first (2012) was a neuroimaging project of earthquake-related PTSD, which was successfully completed in 2016. The second grant (2016), which is currently underway, funded a project examining the effectiveness of a clinical trial of cognitively enhanced psychological therapy for recurrent mood disorders. She is a named investigator on two clinical trials of cognitive remediation interventions in inpatient and outpatient samples, and has published and presented extensively in this area. She is also a named investigator on a study of the subjective experience of cognitive impairment in mood disorders. Katie has received substantial travel grant funding to present at many international conferences, and prestigious awards that have recognised her achievements in clinical psychology.
Dr Frank Giorlando — Committee Member & our Go-to-Techie!
Dr Frank Giorlando is a medical doctor and researcher investigating the perception of time. His research focuses upon integrating basic neuroscience with the psychiatry of dissociation. He is studying at the University of Melbourne and has also been a visiting scholar at the University of Cambridge. His current research includes studies of patients with Bipolar Disorder using the methodologies of psychophysics, computer modelling, MRI and EEG. Frank is a recepient of a Melbourne Research Scholarship and has received grants from the RANZCP, The University of Sydney, ASBDD/Astra Zeneca and Pfizer. He is also working on a theory integrating theoretical physics with non-dualist theory of consciousness.
Dr Lana Williams — Committee Member
Dr Lana Williams is a NHMRC Career Development Fellow and Psychologist with significant experience in psychiatric epidemiology and a special interest in the co-occurrence of physical and mental disorders. She currently is the Head of the Division of Psychiatric Epidemiology within the IMPACT Strategic Research Centre, Deakin University, and also leads GOS Mental Health, a large epidemiological study involving an age-stratified, random, population-based sample of ~3000 men and women. Over the past years, Dr Williams has been developing an innovative program of research examining medical, lifestyle and social correlates of mood, anxiety and personality disorders within the community. Cornerstone is her work investigating the interplay between psychiatric disorders, the medications used to treat these disorders and bone health, which has attracted extensive project funding and personal awards. Her research program is an invaluable resource for collaborative studies, both nationally and internationally and student projects.
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Miss Emmanuelle Bostock is a current University of Tasmania PhD candidate, funded by an Australian Postgraduate Award. She holds a Bachelor of Psychology (Hons) and a Graduate Certificate in Evidence-Based Complementary Medicine. Her research aims to better understand bipolar disorder in relation to a reference condition, temporal lobe epilepsy. To date, she has compared bipolar disorder and temporal lobe epilepsy on precipitating factors and neuropsychology, both of which were published in peer-reviewed journals. In addition, Emmanuelle also has a keen interest in the use of the ketogenic diet (i.e., a high-fat, low-carbohydrate diet) in the treatment of psychiatric disorders.
In 2015, she was awarded a Goddard Sapin-Jaloustre Scholarship to travel to Montpellier (France) where she undertook a course “Research Methods in Psychiatry”. The intensive programme of this summer school was developed by the French National Institute of Health and Medical Research (INSERM) in collaboration with the Institute of Psychiatry, King’s College London. She has also presented posters at various international and national conferences (partly funded by the University of Tasmania).
Melanie Ashton — Committee Member | VIC representative | Scribe
Melanie Ashton is a PhD student in the IMPACT SRC at Deakin University. Melanie has a particular interest in bipolar disorder and the need for a wider range of medications for the depressive phase of the illness. Therefore, for her PhD, she aims to trial a new natural fruit supplement to be taken in addition to current treatments. Melanie has received the ASDBDD / Lundbeck Neuroscience Scholarship to fund the first year of her PhD. She has also received the Australian Rotary Health — Ian Parker Bipolar Research Fund PhD Scholarship for Bipolar
Depressive Disorder Research.
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Miss Jennifer Nicholas — Committee Member | NSW representative | Twitter-in-Charge: https://twitter.com/ASBDD_EMCR
Jennifer is a PhD candidate at the Black Dog Institute in the final stages of her project. Broadly, Jennifer is interested in improving access to evidence-based care and mental health tools and resources through technology. Her PhD research has investigated how smartphone apps can support young adults with bipolar disorder actively manage their mental health. This research has taken a strong consumer focus, with an exploration of consumer needs and perspectives on smartphone apps for disorder management central to the work. She has also investigated the scientific quality of existing resources available to consumers. Jennifer hopes the results will led to the development of acceptable, useful apps for bipolar disorder that meet the needs of young adults with the disorder. By intervening early in young people with bipolar disorder and supporting active disorder management with easy-to-use digital resources, Jennifer hopes to increase the quality of life of individuals living with the condition. She recently won the Black Puppy Award for best research paper on youth mental health. The prize will fund her attendance at the International Society for Research in Internet Interventions conference held this October in Berlin.
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Dr Trung Ngo — Committee Member & Web-Ninja
Trung is currently an Honorary Fellow in the Neurosciences & Cognitive Health program at Mater Research Institute-UQ within the Translational Research Institute and UQ Faculty of Medicine. He completed a PhD in Neuroscience with Jack Pettigrew, employing caloric vestibular stimulation (CVS) — a simple, non-invasive (unihemispheric) brain stimulation technique — to demonstrate evidence for a novel neural mechanism of visual rivalry: the interhemispheric switch model. At Monash Alfred Psychiatry Research Centre, his NHMRC postdoctoral clinical research fellowship focused on investigating rivalry mechanisms and abnormalities in psychiatric groups. Trung’s fellowship studies also examined CVS as a potential therapeutic intervention in persistent (chronic) pain disorders.
He is continuing this body of work with research projects into: (i) novel visual task measures for identifying individuals at increased risk of developing mental illness (e.g., at-risk young people & early psychosis cohorts); (ii) the effectiveness of non-invasive repeated vestibulocortical stimulation (rVCS) protocols as a treatment for depression and related conditions; and (iii) the genetics and neuroimaging of therapeutic response to rVCS, with the aim of elucidating novel electroceutical pathways, response biomarkers and personalised treatment protocols across a spectrum psychiatric and neurological disorders (‘electroceutomics‘).
His other broad research interest entails the thesis that bistable (anti-phase) interhemispheric oscillations are a fundamental neurobiological mechanism — given they’re widely observed in several species (e.g., rodents, birds, cetaceans, humans, Drosophila) and across diverse phenotypes such as biological rhythms (e.g., sleep/wake and menstrual cycles), autonomic functions, oculomotor activity, perception/attention and mood/behaviour changes. Studies in this area will aim to determine whether the underlying genes, neural network dynamics (e.g., vestibulocortical circuitry) and molecular mechanisms are conserved in nature, with significant implications for translational outcomes across psychiatry, neurology and sleep medicine | #PrecisionSwitchMedicine
Connect with Trung on Twitter — https://twitter.com/NgoSense
For email queries regarding this webpage: Trung.Ngo@uq.edu.au