Tier 1 Canada Research Chair in the Neurochemistry of Major Depression. Head of the Neurochemical Imaging Program in Mood and Anxiety Disorders in the Brain Health Imaging Centre, Campbell Family Mental Health Research Institute; and Senior Scientist in the General and Health Systems Psychiatry Division.
Dr. Meyer’s discoveries include:
- first strong evidence for inflammation in the brain during major depressive episodes (JAMA Psych 2015) and that this neuroinflammation (gliosis) can increase with greater duration of untreated illness (Lancet Psych 2018)
- creation of a dietary supplement composed of natural antioxidants and monoamine precursors that prevents depressed mood during postpartum blues in open trial, the prodromal state for postpartum depression (PNAS 2017)
- first evidence that monoamine oxidase A level is elevated in early postpartum, perimenopause and several other dysphoric states with high risk for major depressive episodes, including alcohol dependence, early withdrawal from cigarette smoking and borderline personality disorder (JAMA Psych 2010, 2011, 2014, Biol Psych 2014, 2016)
- first evidence that monoamine oxidase A level is elevated in major depressive episodes (JAMA Psych/Arch Gen Psych 2006, 2009)
- first evidence that monoamine oxidase B level is elevated in the prefrontal brain region in major depressive disorder (JAMA Psych 2019)
- first strong evidence of inflammation in the brain in adult obsessive compulsive disorder, particularly within the implicated cortico-striatal-thalamo-cortical circuit (JAMA Psych 2017)
- selective serotonin reuptake inhibitor antidepressants occupy 80% of the target site (Am J Psych 2001, 2004)
- serotonin transporter binding is increased in the winter relative to summer (JAMA Psych 2008)
- in major depressive disorder with longstanding periods of being medication free, prefrontal and anterior cingulate cortex serotonin 2 and striatal dopamine 2 receptor binding is elevated, particularly when specific symptom dimensions are greater (Am J Psych 2003, 2006), and that the former is diminished after serotonin raising antidepressants (Am J Psych 2001) which implies avoiding serotonin raising antidepressants before giving potential therapeutics like psilocybin that target the serotonin 2 receptor
His publications include more than 130 peer-reviewed papers, 50 per cent as first/senior author. He is the lead/senior author of 20 papers across JAMA Psychiatry/Archives of General Psychiatry, the American Journal of Psychiatry and Lancet Psychiatry.
Dr. Meyer is a full professor at the University of Toronto, Department of Psychiatry. He has received the AE Bennett Award from the Society of Biological Psychiatry; the Distinguished Investigator Award from Brain and Behavior Research Foundation; the Innovations in Psychiatry and Young Investigator Awards from the Canadian College of Neuropsychopharmacoloy; the Samarthji Lal Award from the Graham Boeckh Foundation; the John Dewan Prize from the Ontario Mental Health Foundation and the Royal College Medal Award in Medicine for outstanding contributions to psychiatric research.
Areas of Research
Dr. Meyer’s priorities are identifying mechanisms of treatment-resistant depression, including understanding links to common comorbid illnesses (like SARS-CoV-2 infection, obsessive compulsive disorder, borderline personality disorder, anorexia nervosa and traumatic brain injury); and prevention of major depressive episodes, through identifying and studying modifiable biological markers related to onset, and persistence of major depressive episodes. His current targets of highest interest are neuroinflammation (such as markers of microglial and astroglial activation), monoamine oxidase and markers of synaptic density. He primarily applies neuroimaging, but also uses related markers in preclinical approaches towards understanding mechanisms of psychiatric illness. He is involved in early phase trials of novel therapeutics, phase 0 trials to target pathological markers of depression, and the creation of novel peripheral biomarkers of mood disorders. He has an active program developing new natural health products, particularly in the areas of preventing depressive symptoms such as in early postpartum and perimenopause.
View Dr. Meyer's publications on PubMed.