Psychiatry

I am a psychiatrist with a focus on advancing understanding of the early natural history of mood disorders in youth.  This research aims to understand the nature of inherited vulnerability, describe the natural history and associated biological markers and identify early targets for effective treatment and prevention of recurrence, morbidity and mortality.  I am the principal investigator of a study of offspring of bipolar parents funded by CIHR yielding novel findings characterizing the early clinical stages in the development of bipolar disorder and investigating associated biological, psychological and social influences.  With funding from the CAIP Professorship, I am developing an integrated clinical research program for patients with primary recurrent mood disorders, their adult relatives and children at the FMC.  This translational research platform seeks to advance understanding of mood disorders within individuals over development and across generations. The cornerstone of successful translation research is based on careful clinical characterization.

Research Activities: 1) fMRI of pathological gambling involving cues and the use of gambling tasks, 2) Smoking prevalences in psychiatric populations and pharmacologic cessation strategies for current smokers, 3) Group cognitive behavioural therapy of depressed substance dependent patients. Educational Activities: 1) Development of curriculum guidelines and a national curriculum for addiction psychiatry training in Canada, 2) Psychiatry residency education coordinator for addictions, 3) Royal College examiner and test committee member, 4) Chair of addictions section for Canadian Psychiatric Association coordinating symposia and courses in addictions.

My primary area of research interest includes characterizing, diagnosing and treating neuropsychiatric symptoms of dementia.  I am currently participating in an NIA funded clinical trial of citalopram for agitation in Alzheimer’ Dementia and this will lead to a number of other projects.  Another current protocol involves using the amyloid ligand PIB-PET to assess neuropsychiatric symptoms in temporal lobe dementias.  I have previously published imaging studies of both sleep and appetite disturbances in AD.  I am also interested in the methodology of characterizing symptoms and treatment response and have recently published a comparative analysis of 3 different neuropsychiatric rating scales used in dementia clinical trials. 

Connected to this is an interest in cognition across the neuropsychiatric spectrum and the relationship between late-life anxiety, depression and psychosis to the development of neurodegenerative disease.  We have published a preliminary analysis assessing cognitive profiles in late-life depression versus those with AD in a memory clinic population and we also have ongoing longitudinal studies for cognition in late-life schizophrenia and late-life bipolar disorder.  I have recently constructed a database assessing 5 years of admission data to the geriatric service at the Centre for Addiction and Mental Health in Toronto.  Using comparison data from mood disorder and schizophrenia admissions, we have analyzed predictors of length of stay for geriatric depression.  The data for schizophrenia, dementia and geriatrics as a whole will be completed in the future.  I am interesting in brief cognitive screening for dementia and have published in cognitive screening in primary care and the corresponding article in specialists is in preparation.  I am quite interested in screening bias due to language, education and culture and am validating a non-biased screening tool in my memory clinic population.

Whether it be direct assessment of cognition, neuroimaging, treatment studies or longitudinal characterization of subjects, the overall theme of my research involves cognition and behaviour in older adults.

Endocannabinoids are the brains endogenous version of THC, the psychoactive constituent of cannabis (similar to how endorphins are the body’s endogenous version of morphine). Over the past few years I have been interested in the role of the endocannabinoid system in the regulation of stress and emotional behavior. Research from us, and others, has demonstrated that endocannabinoid signaling largely acts to decrease stress responses. Deficits in endocannabinoid signaling in rodents can increase neuroendocrine and behavioral responses to stress, and in humans, disruption of endocannabinoid signaling can produce symptoms of depression and anxiety. Interestingly, we have demonstrated that stress can mobilize endocannabinoid signaling, and that this increase in endocannabinoid signaling is required for both the normal recovery from acute stress as well as the larger adaptive processes that occur following repeated exposure to stress. More so, we have found that under conditions of chronic stress, endocannabinoid signaling “breaks down”, and that the loss of this buffer system may be one of the mechanisms by which chronic stress increases the risk of affective illnesses, such as depression and anxiety disorders. This hypothesis has been supported by translational clinical studies we have performed demonstrating that circulating levels of endocannabinoids are reduced individuals afflicted with major depression.

The primary focus of research in my laboratory is to understand the role of the endocannabinoid system in the effects of stress and glucocorticoids. Within this focus, my research is particularly interested in determining the role of the endocannabinoid system in the effects of stress on a) neuroendocrine function; b) emotional behaviour; c) energy balance and metabolism; d) neuroinflammation and neurodegeneration. This is achieved through a systems level approach incorporating a range of neuroscientific techniques ranging from cellular/biochemical to behavioural.

The broad goal of my research is to study the impact of the stress response on the regulation of emotion, particularly in young people. Dysfunction in emotional regulation is at the heart of major depression and bipolar disorder, and there is no doubt that stress often plays a pivotal role in these illnesses. Uncovering the neurobiology of mood disorders is the core of my work. Reward processing (an aspect of emotional regulation) in addictions is a developing interest as well.

I also maintain an interest in other psychiatric disorders found in young people, such as Attention Deficit Hyperactivity Disorder, Schizophrenia, and Obsessive Compulsive Disorder, all of which I have worked on in the past.
We use a number of experimental techniques to answer these questions. These include, but are not limited to: (1) volumetric magnetic resonance imaging (manual tracing, voxel based morphometry and cortical thickness), (2) diffusion tensor imaging, (3) magnetic resonance spectroscopy (proton mainly, and phosphorous if possible) and (4) functional magnetic resonance imaging. Obviously, neuroimaging techniques provide only part of the 'whole picture': other tools such as endocrine assessments, behavioral studies and rigorous psychiatric examination must be combined in order to understand the manner in which changes in emotional regulation are related to stress and disease.

The larger, 30,000 feet goal is to have my outcome-focused research have a positive and useful impact upon clinical practice in ways that will better the lives of children affected by mental illness.

My principal scholarly interests are in mood disorders and have a few publications in the same, I also have publication in medical education research. I am particularly interested in patient education as well as in developing instruments to measure clinical outcomes. I have published a number of original articles on treating mood disorders in peer reviewed journals and have done several invited oral presentations, both nationally and internationally. I serve on the review board for a number of Psychiatric journals. I recently completed research in refractory anxiety disorders and in co-morbid adult attention deficit disorder.

The focus of my research interests has been on issues that I consider relevant for psychiatric practice. This includes the application of new technologies to relevant clinical issues with the goal of improving the care of psychiatric patients. In collaboration with the division of cardiac sciences, I currently initiated a study using CMR (cardiovascular magnetic resonance) imaging to study functional and structural cardiac abnormalities in early psychosis. In another study with the Seaman MR Research Centre, we are using abdominal MRI to assess lithium-induced nephropathies.

I regularly supervise medical students and residents during thier psychiatric rotations. Over the last year I have served as Pscychiatry Evaluations Coordinator as well as resident research coordinator for the department of psychiatry. In these positions I try to get medical students and psychiatric residents interested in psychiatric research.

Being a clinical psychiatrist has helped me to identify clinical issues that are relevant for patient-care. Given the abundance of different approaches available at the Hotchkiss Brain Institute, I would like to contribute to the clinical aspects of translation research for neuropsychiatric disorders.