The Diversity of Sleep Research
By Colin Shapiro, PhD, FRCPC
Senior Scientist, Krembil Research Institute
Professor, Department of Psychiatry, University of Toronto
Member, Institute of Medical Science
Sleep medicine is a rapidly evolving field. In the last half century sleep research has prized open many facets of sleep including why do we need good sleep quality and its connection to the functioning of other body systems. However, many intriguing questions remain and one anticipates a huge increase in the emphasis of sleep medicine in health care and in society in general.
Working in this field we are very enthusiastic about running new research projects to answer the questions about blank spots in sleep medicine.
We are currently in the midst of an exciting and unique research project in neurophysiology with linkages to senior researchers at St Michael’s Hospital (Toronto). This project “How sleep deprivation affects brain activity during driving in adolescents and young adults” involves a number of facets including participants mental state and sleep quality assessment, polysomnographic sleep evaluation, excessive daytime sleepiness measurement, the evaluation of driving function using a driving simulator, and the measurement of the brain activity by fMRI while using the driving simulator installed in an fMRI.
Sleep deprivation is a major cause of motor vehicle accidents, and can impair the human brain as much as alcohol. It has been estimated that between 16% and 60% of all motor vehicle accidents are caused by poor sleep (resulting in poor attention). Adolescents and young adults frequently have sleep complaints and this study is unique in this population.
To give a sense of the range of clinical interest in sleep, another study that we are currently doing involves the sleep problems in patients who have recently had a concussion. This is a common problem and sleep sequelae are one of the key presenting features. In this program, the evaluation of circadian rhythms, which involves the objective measurement of melatonin, a rather bizarre test. One stays up in a dark room from 7 pm until 3 am and provides a saliva sample every hour, from which the melatonin level can be assayed. This allows one to establish if the curve of secretion is normal or not. It is a test that is particularly relevant in adolescents especially those who might be going to bed late and getting up late, to try and clarify whether the reason is a biological or a behavioral one.
As an indicator of the impact of sleep disorders most people will have heard of “sleep apnea,” where people repeatedly stop breathing in their sleep. Sleep apnea has been linked to many medical problems including myocardial infarction, stroke, glaucoma, diabetes, impotence, and cognitive decline. One project apparently underway is to look at the impact of early treatment of sleep apnea patients diagnosed with arrhythmia to evaluate whether this facilitates improvement in the arrhythmia. Another project underway concerns the best way to treat sleep apnea in patients with glaucoma.
At the start of the modern era of sleep research the field was dominated by psychiatrists who came from a background of an interest in sleep and dreams. The biological shift has seen an evolution in which respiratory medicine has become a dominant force but there remains much to be learned about psychiatric conditions⎯almost every one of which will have a sleep consequence. The research here is as diverse as trying to evaluate if there are biological markers of depression in the sleep architecture with some recent successes in this area. There is an increased interest in the issue of suicidality being linked to circadian rhythm disruption and sleep difficulties and an increasing awareness that as with hypertension, if one does not treat a sleep problem in depression one is going to have a much more difficult task in managing the condition. These issues and the question of whether many children are mislabeled with ADHD, but really have a sleep problem, is also being studied.
I have often been asked what caused me to be interested in sleep research for over 45 years and my answer somewhat facetiously was that in the textbook for physiology that we studied, there was only one paragraph on the subject of sleep and I realized that if I was going to do a research project it would probably be easy to become an expert in sleep more so than in other areas. I think the real reason was that I recognized that there was a huge chasm of unknown information that would probably be very important and it would be a challenging and exciting sojourn to study sleep. This certainly has been the case and I believe it will be in the future. I often comment that about 60-70 years ago, the only people who measured blood pressure were cardiologists and today every family physician will measure blood pressure. I believe the same will happen with sleep. There is currently a relatively small group of sleep specialists who are evaluating sleep in depth, but with the advance of technology this will become a front line activity in family medicine and those in the sleep field would need to “up their game” and deal with more difficult rather than front line issues.