Serotonin, Anxiety and Visceral Sensation

Healthy Clinical Trial

Official title:

General and Anxiety-Linked Influence of Acute Serotonin Reuptake Inhibition on Neural Responses Associated With Attended Visceral Sensation

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT06212284
• Other study ID #: ER/JL332/9
• Status: Completed
• Phase: N/A
• Start date: February 18, 2018
• Est. completion date: November 14, 2018

Study information

• Verified date: January 2024
• Source: University of Sussex
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 31
• Est. completion date: November 14, 2018
• Est. primary completion date: November 13, 2018
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 35 Years

Eligibility

Inclusion Criteria:

• 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)

Related Conditions & MeSH terms

• Healthy

Intervention

Drug:
• Citalopram 20mg
Doses were delivered in gelatine capsules filled with microcrystalline cellulose.
• Placebo
Doses were gelatine capsules filled with microcrystalline cellulose

Locations

Country	Name	City	State
United Kingdom	School of Psychology	Falmer	East Sussex

Sponsors (1)

Lead Sponsor	Collaborator
University of Sussex

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	relative neural interoceptive response - heart	Neural response, inferred via functional magnetic resonance imaging from focusing attention on the heart, minus the response during focus on a visual stimulus	15 minutes
Primary	relative neural interoceptive response - stomach	Neural response, inferred via functional magnetic resonance imaging from focusing attention on the stomach, minus the response during focus on a visual stimulus	15 minutes
Primary	State Anxiety	State Trait Anxiety Inventory	5 minutes
Secondary	Metacognitive Interoceptive Insight	Ability of confidence to predict accuracy when making decisions about whether heartbeat is in sync with an auditory tone. This is an exploratory measure.	45 minutes
Secondary	Physiological and Psychological state	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.	Measured twice, for 2 minutes, before and after scanning. Average taken to estimate state inside scanner.
Secondary	Positive and Negative Affect Scale	Measures affective state, confirming anxiety measure	Measured twice, for 2 minutes, before and after scanning. Average taken to estimate state inside scanner.
Secondary	Heartrate	Participants had their heartrate recorded with the participant relaxed and sitting.	Before scans of each session, 2 minutes
Secondary	Cerebral Blood Flow Change	Perfusion imaging, to control for effects of citalopram on blood flow	2 minutes, at scan
Secondary	Anatomical scan and fieldmaps	For coregistration of functional magnetic resonance images	6 minutes, at scan