Escitalopram (Lexapro) and citalopram (Celexa) are similar selective serotonin reuptake inhibitors that alter blood flow to the amygdala and other brain structures involved in regulating mood. Escitalopram consists of S-citalopram while citalopram contains both S-citalopram and R-citalopram (racemic citalopram). There is evidence that R-citalopram may block the effects of S-citalopram. The hypothesis being tested is that because of the antagonist effect of R-citalopram, S-citalopram will have a greater effect on the mood circuit than racemic citalopram when equal doses of S-citalopram are administered. The study design consists of a two week medication period followed by blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) while viewing affective visual stimuli.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
TRIPLE
Enrollment
27
One week of escitalopram taken orally at 10 mg followed by one week at 20 mg daily.
One week of citalopram taken orally at 20 mg followed by one week at 40 mg daily.
Two weeks of placebo taken orally.
Steward St. Elizabeth's Medical Center
Boston, Massachusetts, United States
Number of Voxels Showing Greater Activation Following Escitalopram Compared With Citalopram When Happy and Fearful Faces Are Presented in a Rapid Covert Stimulus Presentation.
Activation was measured using BOLD fMRI in response to happy and fearful faces presented in a rapid covert or masked presentation. The response following two weeks of escitalopram was compared to the response following two weeks of citalopram. The cluster of differential activation was located in the left middle temporal gyrus.
Time frame: two weeks
Number of Voxels Showing Greater Activation Following Escitalopram Compared With Citalopram When Faces and a Fixation Stimulus Are Presented in an Overt Presentation.
Activation was measured using BOLD fMRI in response to affective faces and a fixation stimulus presented in an overt or unmasked presentation. The response following two weeks of escitalopram was compared to the response following two weeks of citalopram. The cluster of differential activation was located in the right insular cortex.
Time frame: 2 weeks
Number of Voxels Showing Greater Activation Following Citalopram Compared With Placebo When Affective Faces Are Presented in a Covert Stimulus Presentation and Contrasted With a Fixation Stimulus.
Activation was measured using BOLD fMRI in response to affective (happy and fearful) faces presented in a covert or masked presentation and contrasted with activation in response to a neutral fixation stimulus. The response following two weeks of citalopram was compared to the response following two weeks of placebo. The cluster of differential activation was located in the right occipital fusiform gyrus.
Time frame: 2 weeks
Number of Voxels Showing Greater Activation Following Citalopram Compared With Placebo When Affective Faces Are Presented in a Covert Stimulus Presentation and Contrasted With a Fixation Stimulus.
Activation was measured using BOLD fMRI in response to affective (happy and fearful) faces presented in a covert or masked presentation and contrasted with activation in response to a neutral fixation stimulus. The response following two weeks of citalopram was compared to the response following two weeks of placebo. The cluster of differential activation was located in the right lateral occipital cortex.
Time frame: 2 weeks
Number of Voxels Showing Greater Activation Following Escitalopram Compared With Placebo When Affective Faces Are Presented in a Covert Stimulus Presentation and Contrasted With a Fixation Stimulus.
Activation was measured using BOLD fMRI in response to affective (happy and fearful) faces presented in a covert or masked presentation and contrasted with activation in response to a neutral fixation stimulus. The response following two weeks of escitalopram was compared to the response following two weeks of placebo. The cluster of differential activation was located in the right inferior lateral occipital cortex.
Time frame: 2 weeks
Number of Voxels Showing Greater Activation Following Placebo Compared With Citalopram When Affective Words Are Contrasted With a Fixation Stimulus.
Activation was measured using BOLD fMRI in response to affective words contrasted with activation in response to a neutral fixation stimulus. The response following two weeks of placebo was compared to the response following two weeks of citalopram. The cluster of differential activation was located in the right lingual gyrus and right superior lateral occipital cortex.
Time frame: 2 weeks
Number of Voxels Showing Greater Activation Following Escitalopram Compared With Citalopram When Affective Words Are Contrasted With a Fixation Stimulus.
Activation was measured using BOLD fMRI in response to affective words contrasted with activation in response to a neutral fixation stimulus. The response following two weeks of escitalopram was compared to the response following two weeks of citalopram. The cluster of differential activation was located in the left primary visual cortex.
Time frame: 2 weeks
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.