Carleton undergraduate journal of science.
September 2, 2025
Kaylee Reid, Dhiral Kot, Argel Aguilar‐valles
Major depressive disorder affects about 280 million people globally, and many do not respond to first-line antidepressants, leading to treatment-resistant depression. Psychedelics like psilocybin show rapid antidepressant effects by enhancing neuroplasticity through 5-HT2A receptor activation, but their hallucinogenic properties limit clinical use. A non-hallucinogenic analog, 2-bromo-lysergic acid diethylamide (2-Br-LSD), may promote neuroplasticity without hallucinations, though it is unclear if hallucinatory activity is necessary for therapeutic benefit. This thesis examines both compounds in rodent models of chronic stress, hypothesizing that both will reduce depression-like behaviors by modulating mood-regulating neural circuits, aiming to assess 2-Br-LSD as a more accessible treatment for treatment-resistant depression.
Carleton undergraduate journal of science.
September 2, 2025
Maham Khurram
Anorexia nervosa involves compulsive eating restrictions and cognitive inflexibility linked to dysregulation in cortico-striatal-thalamo-cortical circuitry, particularly the dorsolateral prefrontal cortex and dorsal striatum, which reinforces maladaptive habits. Current treatments like cognitive behavioral therapy and medications are ineffective at addressing these neural dysfunctions. Recent research suggests psilocybin can modulate cortico-striatal function, improving rigid behavioral patterns and restoring goal-directed control over eating. Animal studies and human trials provide evidence that psilocybin therapy promotes cognitive flexibility and disrupts maladaptive decision-making, showing strong therapeutic potential for eating disorders by restoring functional connectivity in CSTC circuits.
Carleton undergraduate journal of science.
May 16, 2025
Sumika Egner
Ketamine, long used as an anesthetic, also reduces depressive symptoms at lower doses, especially in people with treatment-resistant depression (TRD) for whom standard antidepressants often fail. Pre-clinical studies of ketamine's two mirror-image forms—R-ketamine and S-ketamine—suggested that R-ketamine might work faster, last longer, and cause fewer side effects and less risk of abuse. However, early clinical trials testing R-ketamine for TRD have not yet shown clear antidepressant benefits, even though the drug appeared safe and tolerable. This review compares the two enantiomers and concludes that while R-ketamine looked promising in animal studies, it did not consistently reduce depression in human trials, making its effectiveness uncertain.