Serotonin, Anxiety and Visceral Sensation
- Registration Number
- NCT06212284
- Lead Sponsor
- University of Sussex
- Brief Summary
The goal of this crossover study was to learn about the potential regulatory role of serotonin in interoceptive processing and its relationship to levels of state anxiety. This experiment directly compared the impact of a selective serotonin reuptake inhibitor (SSRI) (20mg CITALOPRAM) to that of a PLACEBO on the neural processing of ordinary interoceptive sensations and the relationship of these influences to anxious states.
Healthy young volunteers completed the visceral interoceptive attention task with each treatment condition (citalopram and placebo). The task involves focusing attention on heart, stomach, or visual sensation control while scanned with functional magnetic resonance imaging (fMRI). The difference in haemodynamic response between interoceptive sensation(s) and visual sensation (i.e. the relative interoceptive response) is compared between treatment conditions. State anxiety is measured at each test period. It is used to test for a moderating effect of state anxiety on the influence of serotonin in interoceptive processing and used post-hoc to explore associations between changes in state anxiety and changes of interoceptive relative interoceptive response due to the SSRI.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 31
- healthy volunteer
Exclusion criteria included:
- the presence of significant ongoing medical condition;
- pregnancy or breastfeeding;
- currently taking any medication (excluding contraceptive pill);
- first-degree family history of bipolar disorder;
- an indication of current or historical mental health disorder,
- MRI scanner contraindications (e.g. metallic implants)
- data that is unanalyzable due to movement
- excessive side effects of the drug (e.g. nausea)
Not provided
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description citalopram first, placebo second Citalopram 20mg Citalopram was taken first. Placebo was taken at least 7 days later. citalopram first, placebo second Placebo Citalopram was taken first. Placebo was taken at least 7 days later. placebo first, citalopram second Placebo Placebo was taken first. Citalopram was taken at least 7 days later. placebo first, citalopram second Citalopram 20mg Placebo was taken first. Citalopram was taken at least 7 days later.
- Primary Outcome Measures
Name Time Method relative neural interoceptive response - heart 15 minutes Neural response, inferred via functional magnetic resonance imaging from focusing attention on the heart, minus the response during focus on a visual stimulus
relative neural interoceptive response - stomach 15 minutes Neural response, inferred via functional magnetic resonance imaging from focusing attention on the stomach, minus the response during focus on a visual stimulus
State Anxiety 5 minutes State Trait Anxiety Inventory
- Secondary Outcome Measures
Name Time Method Metacognitive Interoceptive Insight 45 minutes Ability of confidence to predict accuracy when making decisions about whether heartbeat is in sync with an auditory tone. This is an exploratory measure.
Physiological and Psychological state Measured twice, for 2 minutes, before and after scanning. Average taken to estimate state inside scanner. Three scales (from 0-100) were given to assess three somatic side effects (nausea, headache and dizziness). Five anxiety-related effects (pairs of antonyms: alert-drowsy, stimulated-sedated, restless-peaceful, irritable-good-humoured, anxious-calm) were used to confirm other anxiety measures and alert the researchers to excessive side effects. Used to confirm anxiety measure detect side effects.
Cerebral Blood Flow Change 2 minutes, at scan Perfusion imaging, to control for effects of citalopram on blood flow
Positive and Negative Affect Scale Measured twice, for 2 minutes, before and after scanning. Average taken to estimate state inside scanner. Measures affective state, confirming anxiety measure
Heartrate Before scans of each session, 2 minutes Participants had their heartrate recorded with the participant relaxed and sitting.
Anatomical scan and fieldmaps 6 minutes, at scan For coregistration of functional magnetic resonance images
Trial Locations
- Locations (1)
School of Psychology
🇬🇧Falmer, East Sussex, United Kingdom