Improving treatment of major depressive disorder is a pressing matter since less than 50% of patients treated with antidepressant drugs respond to the intervention. If they do, there is a latency period before achieving relief. Sleep deprivation therapy has been shown to act as a rapid antidepressant in humans and animals. Using the forced swim test, this study evaluated the role of the endocannabinoid system, specifically CB1 receptors, in the antidepressant effects of sleep deprivation in male Sprague Dawley rats. Rats were assigned to one of the three conditions: 24 hours of sleep deprivation (SD), 24 hours of sleep deprivation plus administration of a CB1 receptor antagonist, AM251 (SDAM), and no intervention (control). Sleep deprivation was achieved via the flowerpot method. It was hypothesized that SD rats would demonstrate the lowest level of learned helplessness and that SDAM rats would be similar to control rats because of CB1 blockade by AM251. Results showed that sleep deprived rats, both SD and SDAM, demonstrated significantly lower immobility scores compared to their control counterparts, suggesting an antidepressant-like effect. Antagonizing CB1 receptors did not prevent the antidepressant effect as predicted, but SDAM rats, like control rats, showed lower climbing scores compared to SD rats. It is possible that sleep deprivation works by enhancing the noradrenergic system and CB1 receptors play a role enhancing the activity of the noradrenergic system. The modulatory action of CB1 receptors should be further explored in the context of depression and rapid antidepressants.


Stavnezer, Amy Jo




Behavioral Neurobiology


depression, sleep deprivation therapy, endocannabinoid system, AM251, forced swim test.

Publication Date


Degree Granted

Bachelor of Arts

Document Type

Senior Independent Study Thesis



© Copyright 2023 María Dolores Ferreira