Before presenting his St. Mary's Project in psychology via poster on campus at the Michael P. O'Brien Athletics and Recreation Center during SMP Days on May 2, James Atwell '23 presented his research via oral presentation at the Mid-Atlantic Undergraduate Psychology Conference hosted by Harford Community College in Bel Air, MD on April 21. His project entitled "Special K: Effects of (R)-ketamine on Animal Models of Depression" was mentored by Professor of Psychology Aileen Bailey.
Major depressive disorder (MDD) is noted as one of the world's most common psychopathological disorders and has been shown to grow nearly 50% over the past decade. Pharmaceutical drugs such as Selective Serotonin Reuptake Inhibitors (SSRIs) have been commonly used to treat MDD however, research has found various flaws in the use of this form of treatment. There has been further research for pharmaceutical treatments for MDD, one of which being ketamine. Medication containing esketamine has been FDA approved however, there is limited research in the latter of racemic ketamine ((R)-ketamine). (R)-ketamine has been shown to produce stronger, safer, and more efficient antidepressant-like effects compared to the latter (S)-ketamine. The current study aims to further explore the effects of (R)-ketamine using an animal model of depression. Sixteen male Sprague-Dawley rats were exposed to 28 days of chronic unpredictable stress (CUS) and then administered a 3.1mg/kg i.p. injection of (R)-ketamine or saline. Twenty-four hours following the injections, rodents underwent a sucrose preference test and forced swim test (FST) to explore the antidepressant-like effects of (R)-ketamine. The FST found significantly lower immobility rates in rodents injected with (R)-ketamine compared to saline. Additionally, there was a significant increase in climbing rates during the FST for animals injected with (R)-ketamine. The sucrose preference test showed no significant main effect between injection types on sucrose preference. Overall, the results suggest that (R)-ketamine may be an option for treating depression as it expresses antidepressant-like effects. Further research may explore different behavior measures (i.e., social interaction), sex differences, and different models of depression. Additionally, further research could explore how (R)-ketamine may assist other conditions, such as addiction and chronic pain.
Atwell is currently a post-baccalaureate trainee in Dr. Geoffrey Schoenbaum's lab at the National Institute on Drug Abuse and pursuing traineeship certification. Once completing traineeship, he will apply to either a PhD program in clinical neuropsychology or medical school in efforts to become a developmental pediatrician.
