Effects of Escitalopram on the Functional Neural Circuits in an Animal Model of Adolescent Depression.

Purpose: Although escitalopram is known to be an effective drug for adult depression, its disease-modifying efficacy on adolescents remains controversial. The present study aimed to evaluate the therapeutic effect of escitalopram on behavioral aspects as well as functional neural circuits by means of positron emission tomography.
Procedures: To generate the animal models of depression, restraint stress was used during the peri-adolescent period (RS group). Thereafter, escitalopram was administered after the end of stress exposure (Tx group). We performed NeuroPET studies of glutamate, glutamate, GABA, and serotonin systems.
Results: The Tx group showed no body weight change compared to the RS group. In the behavioral tests, the Tx group also displayed the similar time spent in open arms and immobility time to those for RS. In the PET studies, brain uptake values for the Tx group revealed no significant differences in terms of glucose, GABA _A , and 5-HT _1A receptor densities, but lower mGluR5 PET uptake compared to the RS group. In the immunohistochemistry, the Tx group showed the significant loss of neuronal cells in the hippocampus compared to the RS group.
Conclusion: The administration of escitalopram had no therapeutic effect on the adolescent depression.
(© 2023. The Author(s), under exclusive licence to World Molecular Imaging Society.)