None listed
Conditions
Brief summary
This study will investigate the influence of a selective serotonin reuptake inhibitor (SSRI; citalopram) on the brains response to light stimuli, using fMRI scans. Participants will be healthy young men and women. Participants will complete two seperate fMRI scans, with ~1 week between scans. At each scan, participants will take either a single dose of citalopram 30mg, or placebo (in a randomised order) prior to undergoing a scan during which they are exposed to alternating periods of light and dark. We hypothesise an increase in the brain's response to light after citalopram administration, relative to placebo.
Interventions
Participants will undergo an fMRI scan during which they are exposed to alternating ~30 second periods of light exposure, and ~30 second periods of dim light/darkness. A single dose of citalopram 30mg will be administered ~1 hour prior to the commencement of the scan. The total duration of the fMRI scan will be ~45 minutes. There will be a washout period of ~1 week between the active and control conditions.
fMRI sequence details are as follows: Gradient-echo echo-planar imaging (GRE-EPI) accel
Participants will undergo an fMRI scan during which they are exposed to alternating ~30 second periods of light exposure, and ~30 second periods of dim light/darkness. A single dose of citalopram 30mg will be administered ~1 hour prior to the commencement of the scan. The total duration of the fMRI scan will be ~45 minutes. There will be a washout period of ~1 week between the active and control conditions. fMRI sequence details are as follows: Gradient-echo echo-planar imaging (GRE-EPI) accelerated by parallel imaging using GRAPPA. TE = 30 ms, TR = 2.52 s, GRAPPA factor = 2, PE direction = anterior–posterior, FOV = 220 × 210 mm2, matrix size = 88 × 84, in-plane resolution = 2.5 × 2.5 mm2, slice thickness = 2.5 mm, inter-slice gap = 0.625 mm, and slice tilt = 40°. 45 slices acquired in ascending order for whole brain coverage including the lower brainstem.
Sponsors
Monash University
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
Healthy Caucasian males and females
Exclusion criteria
- Any current diagnoses of psychiatric illness or use of psychiatric medication - Current sleep disorders or erratic/unusual sleep patterns - Recent or excessive illicit drug use - Current use of any prescription medication - Colourblindness - Recent surgery involving a full anaesthetic - Any night shift work within the past 3 months - Any travel outside of the current time zone within the last 3 months - BMI less than 18 or greater than 30 - Use of hormonal contraception - Abnormal menstrual cycle (abnormally long, short or unpredictable)
Outcome results
None listed