depression

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.

Dr. Donald Addington is a professor in the Department of Psychiatry and the interim director of the Mathison Centre for Mental Health Research and Education.  Dr. Addington is active in research, education clinical practice and administration. His research activities include health services research and knowledge synthesis with a focus on quality and outcome of schizophrenia and particularly First Episode Psychosis Services. His most recent activity has been the development of a Fidelity Scale for First Episode Psychosis Services. He has over 120 peer reviewed publications and has received grants from the National Institutes of Health, Canadian Institutes of Health Research and Alberta Heritage Foundation for Medical Research. Dr. Addington established the psychosis research group at the University of Calgary in 1986. This group has continued to the present time and is now a component of the Mathison Centre. In 1990 published the Calgary Depression Scale for Schizophrenia which has become the internationally recognized gold standard for the assessment of depression in schizophrenia and has been translated into 35 languages? Nationally Dr. Addington has chaired working groups for the development of the Canadian Clinical Practice Guidelines for Schizophrenia. In Calgary he has obtained competitive health services grant support to develop the First Episode Psychosis services comprised of both first episode psychosis clinics and specialized clinics for those at high risk of developing schizophrenia. These services have now become established components of Alberta Health Services. In addition to his research career Dr. Addington was for 11 years the Chairman of the Department of Psychiatry at the University of Calgary and Head Calgary Health Region Regional Clinical Department of Psychiatry. He has served on a number of committees for the Canadian Institutes for Health Information, the Mental Health Commission of Canada, the Royal College of Physicians and Surgeons of Canada. In 2011 he was asked to write an invited commentary for the US Department of Health and Human Services, Agency for Health Care Research and Quality, on Performance Measures for evaluation and quality improvement in the care of individuals with a First Episode Psychosis. He is serving his second term as the Chairman of the Board of the Canadian Psychiatric Association.