Recruitment

Recruitment Status
Recruiting
Estimated Enrollment
Same as current

Summary

Conditions
  • Antidepressive Agents
  • Cognition
  • Depression
  • Depressive Disorder
  • Mental Disorder
  • Molecular Mechanisms of Pharmacological Action
Type
Interventional
Phase
Not Applicable
Design
Allocation: RandomizedIntervention Model: Parallel AssignmentIntervention Model Description: Following the screening, eligible participants will be randomised to receive either a single 20mg oral dose of citalopram or a matched lactose placebo tablet using an online randomisation tool. Note that the study is not assessing the safety or efficacy of citalopram, but rather using it as a probe to understand the role of serotonin in self-referential emotional processing biases.Masking: Triple (Participant, Investigator, Outcomes Assessor)Primary Purpose: Basic Science

Participation Requirements

Age
Between 18 years and 45 years
Gender
Both males and females

Description

Antidepressants are thought to operate by changing the way patients process emotional information. After a single dose of citalopram or fluoxetine healthy volunteers have been found to display an increased recognition of happy facial expressions and a reduced recognition of sad faces, in the absence...

Antidepressants are thought to operate by changing the way patients process emotional information. After a single dose of citalopram or fluoxetine healthy volunteers have been found to display an increased recognition of happy facial expressions and a reduced recognition of sad faces, in the absence of changes in mood. Studies using depressed participants have produced similar results. However, there has been comparatively little research on changes in emotional processing biases about the self following antidepressant administration. Sense of self has been proposed as fundamental for mental health, with self-schemas acting as a focus through which valence and reward influenced perception, memory and decision-making. Antidepressants may increase learning of positive information about the self, potentially remediating negative self-schema and subsequently reducing depression symptoms. In this study, the investigators aim to examine whether acute administration of citalopram is associated with an increase in positive emotional learning biases about the self. Using a parallel-group double-blind design, participants will be randomised to receive either an acute dose of citalopram or placebo. Participants will then complete a number of widely used computer-based cognitive tasks measuring emotional processing biases. Identifying early changes in cognition and behaviour following antidepressant treatment will increase our knowledge of how antidepressants operate, and provide putative targets to identify early response to antidepressants. This study has also been registered on OSF: https://osf.io/nhjvs/?view_only=b39c49bddfd543b99b627dc992e49b45 Starting from the 8th November 2019 an additional task (the Oxford Cognition Stress Task (OCST)) was included in the test battery. This task has been developed by the Psychopharmacology and Emotion Research Laboratory (PERL), Department of Psychiatry, University of Oxford. This is an acute psychosocial stress induction paradigm, comprised of computerised cognitive tasks with an induced failure component. An algorithm varies task timing/difficulty to be just beyond participants' ability, accompanied by aversive feedback. The OCST induces mild, transient increases in stress and arousal, as indexed by heart rate, skin conductance, salivary cortisol and self-reported subjective state measures. Data for this task will be collected, analysed and published by PERL and will not be included in any publications relating to the previous registration for this study. The OCST task has been included at the end of the test battery and is therefore not expected to influence data relating to any self-report measures or tasks outlined in the previous registration This section of the study has been registered separately on ClinicalTrials.gov (titled 'Citalopram and Stress Reactivity') to reflect the separate research questions and study team involvement.

Tracking Information

NCT #
NCT04169230
Collaborators
University of Bath
Investigators
Principal Investigator: Catherine Harmer, DPhil University of Oxford Principal Investigator: Katherine S Button, PhD University of Bath