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OpenTrials
Completed

NCT Number: NCT07074652

The Effect of SSRIs on Threat of Shock Potentiated Neural Circuitry

This study aims to increase the knowledge about psychological processes which may contribute to mental health problems such as depression and anxiety. This study aims to investigate if administering Escitalopram, an antidepressant which increases serotonin levels in parts of the brain, affects how the brain processes emotional information. It is hoped that measuring these changes will increase the understanding of processes involved in mental health problems.

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Key information

Conditions

Anxiety Anxiety Disorders Mental Disorders

Age range

18 year–50 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University College London

London, United Kingdom

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Healthy Controls:

  • Fluency in English
  • Registration with a UK General Practitioner
  • Capacity for consent
  • No personal history of long-term medical conditions or psychiatric illness (including substance dependence, assessed with the Mini International Neuropsychiatric Interview)

Anxious Individuals:

  • Fluency in English
  • Registration with a UK General Practitioner
  • Capacity for consent
  • Meeting criteria for generalised anxiety disorder, panic disorder and/or agoraphobia (also assessed with the Mini International Neuropsychiatric Interview); permitted comorbid conditions were: major depressive disorder, obsessive-compulsive disorder and/or post-traumatic stress disorder

Exclusion criteria

Healthy Controls and Anxious Individuals:

  • Having consumed alcohol within 12 hours prior to the study
  • having used illicit drugs within 3 months prior to the study
  • Having had any contraindications to MRI scanning
  • Being pregnant or breastfeeding
  • Having had impaired or uncorrected vision or hearing

Treatment and study plan

Escitalopram

Drug

Participants received 2-3 weeks of escitalopram.

Placebo

Drug

Participants received 2-3 weeks of placebo, matched in colour and size to the escitalopram.

Primary outcomes

  1. 'Aversive amplification circuit' connectivity

    Time frame: Baseline and 2-3 weeks after baseline

    The engagement of the neural circuit of the amygdala, cingulate cortex and prefrontal cortex will be measured via an fMRI analysis technique called a psychophysiological interactions (PPI) analysis. PPI analysis concerns behaviour-specific increases in the relationship across regional brain activity - this means that it can allow one to assess whether two regions (a priori selected ROIs) show increased connectivity during a specific context or behaviour, suggesting a behaviour-specific increase in transfer of information. The output of this analysis will take form of a continuous beta weight - an index of connectivity across two brain regions (amygdala and medial prefrontal cortex), which represents the primary outcome of the study.

Secondary outcomes

  1. Cognitive task performance: Loss/risk aversion task

    Time frame: Baseline and 2-3 weeks after baseline

    Measures how averse participants are to risk and loss in a mock gambling context

  2. Cognitive task performance: Go/no-go task

    Time frame: Baseline and 2-3 weeks after baseline

    Measures approach/avoidance behaviours under threat of shock or safe conditions

  3. Cognitive task performance: Facial emotional processing task

    Time frame: Baseline and 2-3 weeks after baseline

    Measures brain responses to positive, negative and neutral emotions

  4. Cognitive task performance: Emotional face recognition task

    Time frame: Baseline and 2-3 weeks after baseline

    Measures brain responses during two distinct memory processes - the encoding (learning) and retrieval (remembering) of information

  5. Cognitive task performance: Visual affective bias task

    Time frame: Baseline and 2-3 weeks after baseline

    Measures biases in patients' cognition towards or away from rewarding stimuli

  6. Regional activations during neuroimaging task: Facial emotional processing task

    Time frame: Baseline and 2-3 weeks after baseline

    Measures brain responses to positive, negative and neutral emotions

  7. Regional activations during neuroimaging task: Emotional face recognition task

    Time frame: Baseline and 2-3 weeks after baseline

    Measures brain responses during two distinct memory processes - the encoding (learning) and retrieval (remembering) of information

  8. Regional activations during neuroimaging task: Visual affective bias task

    Time frame: Baseline and 2-3 weeks after baseline

    Measures biases in patients' cognition towards or away from rewarding stimuli

  9. Clinical symptom measure: Generalised Anxiety Disorder Scale (GAD-7)

    Time frame: Baseline and 2-3 weeks after baseline

    Measures symptoms of generalised anxiety, scored between 0-21 with higher scores indicating more severe symptoms

  10. Clinical symptom measure: State Trait Anxiety Inventory (STAI)

    Time frame: Baseline and 2-3 weeks after baseline

    Measures state and trait anxiety symptoms, scored between 20-80 with higher scores indicating more severe symptoms

  11. Clinical symptom measures: Patient Health Questionnaire (PHQ-9)

    Time frame: Baseline and 2-3 weeks after baseline

    Measures depressive symptoms, scored between 0-27 with higher scores indicating more severe symptoms

  12. Clinical symptom measures: Beck's Depression Inventory (BDI)

    Time frame: Baseline and 2-3 weeks after baseline

    Measures depressive symptoms, scored between 0-63 with higher scores indicating more severe symptoms

  13. Clinical symptom measures: Catastrophizing questionnaire

    Time frame: Baseline and 2-3 weeks after baseline

    Measures catastrophising, scored between 24-120 with higher scores indicating more severe symptoms

  14. Clinical symptom measures: Daily Stress Inventory (DSI)

    Time frame: Baseline and 2-3 weeks after baseline

    Measures frequency and impact of daily stresses. Frequency scored between 0-58 and impact scored between 0-6, with higher scores indicating more severe stress

  15. Clinical symptom measures: Behavioural Inhibition/Behavioural Activation Scales (BIS/BAS)

    Time frame: Baseline and 2-3 weeks after baseline

    Measures drive, fun-seeking, reward responsiveness and behavioural inhibition. Behavioural inhibition scored between 7-28, drive between 4-16, fun seeking between 4-16, and reward between 5-20, with higher scores indicating higher levels of those behaviours

  16. Clinical symptom measures: Eysenck Impulsiveness Scale

    Time frame: Baseline and 2-3 weeks after baseline

    Measures impulsiveness, venturesomeness and empathy. Impulsivity scored between 0-19, venturesomeness between 0-16, empathy between 0-18, with higher scores indicating higher levels of those traits

Sponsors and collaborators

Lead sponsor

UCLH/UCL Joint Research Office

Other

Collaborators

  • University College, London

Registry information

Important dates

Study start
2017
Primary completion
2022
Study completion
2022
First posted
Jul 20, 2025
Registry last updated
Jul 20, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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