A Comparison of the CNS Effects of Equivalent Doses of Escitalopram and Racemic Citalopram Using BOLD fMRI
试验速览
- 阶段
- 4 期
- 状态
- 已完成
- 发起方
- 入组人数
- 27
- 试验地点
- 1
- 主要终点
- Number of Voxels Showing Greater Activation Following Escitalopram Compared With Citalopram When Happy and Fearful Faces Are Presented in a Rapid Covert Stimulus Presentation.
研究概览
简要总结
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.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 21 Years 至 50 Years（Adult）
- 性别
- Male
- 接受健康志愿者
- 是
入选标准
- •Healthy male aged 21 to 50 years.
- •Capable of providing informed consent.
- •Has an established residence and phone.
排除标准
- •Meets DSM-IV criteria for an Axis I or II disorder.
- •History of substance dependence or abuse within the past month.
- •Use of NSAID's, beta blockers, calcium channel blockers, antidepressants, antipsychotic medications, lithium or other medication which in the opinion of the investigator would alter vascular responsivity.
- •Regular use of sedative hypnotic or narcotic medication, or other medication that might affect the individual's perception of visual stimuli.
- •History of cataracts or significant visual impairment.
- •A medical condition, which in the opinion of the investigator is likely to affect the individual's perception of the visual stimuli or vascular response.
- •Participation in a research protocol that included administration of medication within the past 3 months.
- •Cigarette smoking.
研究组 & 干预措施
Escitalopram
One week of escitalopram at 10 mg followed by one week at 20 mg in healthy volunteers.
干预措施: Escitalopram (Drug)
Citalopram
One week of citalopram at 20 mg followed by one week at 40 mg in healthy volunteers.
干预措施: Citalopram (Drug)
Placebo
Two weeks of placebo in healthy volunteers.
干预措施: Placebo (Drug)
结局指标
主要结局
Number of Voxels Showing Greater Activation Following Escitalopram Compared With Citalopram When Happy and Fearful Faces Are Presented in a Rapid Covert Stimulus Presentation.
时间窗: two weeks
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.
次要结局
- Number of Voxels Showing Greater Activation Following Placebo Compared With Citalopram When Affective Words Are Contrasted With a Fixation Stimulus.(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.(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.(2 weeks)
- Number of Voxels Showing Greater Activation Following Escitalopram Compared With Citalopram When Affective Words Are Contrasted With a Fixation Stimulus.(2 weeks)
- Number of Voxels Showing Greater Activation Following Escitalopram Compared With Citalopram When Faces and a Fixation Stimulus Are Presented in an Overt Presentation.(2 weeks)
研究者
Michael Henry, MD
Principal Investigator
Steward St. Elizabeth's Medical Center of Boston, Inc.