MedPath

The Role of Serotonin in Compulsive Behavior in Humans: Underlying Brain Mechanisms

Phase 4
Active, not recruiting
Conditions
Obsessive-Compulsive Disorder/High Compulsive Individuals
Healthy Individuals
Interventions
Drug: Placebo oral tablet
Registration Number
NCT04336228
Lead Sponsor
Rigshospitalet, Denmark
Brief Summary

The aim of this project is to investigate:

* The status of the central serotonin (5-hydroxytryptamine, 5-HT) system in compulsive behaviour and how it is affected by sub-chronic escitalopram administration

* The mechanisms underlying how sub-chronic administration of escitalopram affects the central 5-HT system

* How changes in cognitive performance, including the balance between habitual and goal-directed mechanisms, are affected in compulsive behaviour by boosting 5-HT function

* How functional brain changes in cognitive function measured with magnetic resonance imaging relate to altered 5-HT function following escitalopram administration.

Detailed Description

Previous studies have shown that 5-HT is strongly implicated in compulsive behaviours in experimental animals. Manipulation of 5-HT influences neuronal interactions underlying action selection. Reduced forebrain 5-HT causes perseveration and impairs goal-directed behaviour under reward but not punishment. Dysfunctional 5-HT neurotransmission has also been implicated in Obsessive-Compulsive Disorder (OCD) based on the selective efficacy of relatively high doses of selective serotonin reuptake inhibitors (SSRIs) in treating this disorder. Hitherto, it is unknown whether there is a primary defect in the serotonergic system or whether SSRIs ameliorate symptoms by modulating other brain neurotransmitter pathways. So far, only one study of central 5-HT release in OCD patients has been conducted and its methodology may be questioned.

A number of behavioural and cognitive features of OCD, including endophenotype markers that appear to characterise the disorder have been determined. These include a shift in cognitive control from a goal-directed strategy to a habitual (stimulus-response, S-R) strategy, cognitive rigidity in terms of both reversal learning and attentional set-shifting, impaired response inhibition and planning, and a tendency to over-respond to spurious negative feedback in a probabilistic learning paradigm. Neural substrates of these deficits are being investigated using brain imaging methodologies based on magnetic resonance and preliminary evidence suggests an over-active medial prefrontal cortex-caudate nucleus circuits and underactive lateral prefrontal cortex-putamen circuits. However, little evidence exists that relates to the hypothesis of an over-active habit system in this disorder or to the role of serotonin in all these cognitive and behavioural deficits observed in OCD and compulsivity in general.

Recruitment & Eligibility

Status
ACTIVE_NOT_RECRUITING
Sex
All
Target Recruitment
46
Inclusion Criteria
  • Individuals with high scores on obsessive-compulsive traits (with or without a diagnosis of OCD established by a psychiatrist) and healthy volunteers (male or female) between 18 and 70 years. Compulsive individuals without an OCD diagnosis are individuals without a history of psychiatric or other major medical conditions but scoring abnormally high on the Obsessive-Compulsive Inventory (OCI) questionnaire.
Exclusion Criteria
  • Current or previous neurological disease, severe somatic disease, or consumption of medical drugs likely to influence the test results
  • Non- fluent in Danish or pronounced visual or auditory impairments
  • Current or past learning disability.
  • Pregnancy
  • Lactation
  • Participation in experiments with radioactivity (> 10 mSv) within the last year or significant occupational exposure to radioactivity.
  • Contraindications for MRI (pacemaker, metal implants, etc.).
  • Allergy to the ingredients in the administered drug.
  • Abnormal ECG (e.g. prolonged QT syndrome).
  • Dizzy when changing from supine to upright position (e.g. postural orthostatic tachycardia syndrome).
  • Mild hypotension (blood pressure below 100/70 mmHg) or hypertension (blood pressure above 140/90 mmHg).
  • Head injury or concussion resulting in loss of consciousness for more than 2 min.
  • Alcohol or drug abuse
  • Drug use other than tobacco and alcohol within the last 30 days.
  • Hash > 50 x lifetime.
  • Drugs > 10 x lifetime (for each substance).
  • Current medication with serotonergic acting compounds. Use of other psychoactive substances must be stable at least one month prior to inclusion and maintained throughout the study.
  • Severe physical impairments affecting eyesight or motor performance.
  • For the OCD group: other Axis I mental disorder as primary diagnosis according to ICD-10 criteria.
  • For healthy volunteers: any current or former primary psychiatric disorder (Axis I WHO ICD-10 diagnostic classification).

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Healthy Control GroupPlacebo oral tabletThe healthy placebo control group will be administered the exact same procedure as the intervention group, the only difference being that this group will be administered a placebo tablet.
Obsessive-Compulsive Disorder / High Compulsivity Control GroupPlacebo oral tabletThe OCD/high compulsivity placebo control group will be administered the exact same procedure as the intervention group, the only difference being that this group will be administered a placebo tablet.
Healthy Intervention GroupEscitalopramThe healthy intervention group will be administered 20mg of Escitalopram daily for 3-4 weeks.
Obsessive-Compulsive Disorder / High Compulsivity Intervention GroupEscitalopramThe OCD/high compulsivity intervention group will be administered 20mg of Escitalopram daily for 3-4 weeks.
Primary Outcome Measures
NameTimeMethod
Learning Primary Outcome 2 measured with Probability Reversal Learning test: Mean errors Stage 2 (Reversal)3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Habit formation outcome 3: confidence and enjoyable rates.3 Years

Daily app training paradigm

Learning Primary Outcome 1 measured with Probability Reversal Learning test: Mean errors Stage 1 (Learning)3 years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Inhibition Primary Outcome 1 measured with Interleaved Stop Signal Task/Go-NoGo: Stop Signal Reaction Time3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains.

Flexibility Primary Outcome 1 measured with 3Dimensional Intra/Extra Dimensional Shift test: Extra Dimensional Set Errors3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains.

Flexibility Primary Outcome 2 measured with Sequential model-based model-free test: Model-based Model-free Weight3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains.

Emotion Recognition Primary Outcome 1 measures with EMOTICOM Intensity Morphing: Affective bias in decreasing condition3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Emotion Recognition Primary Outcome 3 measured with EMOTICOM Intensity Morphing task: Detection threshold decreasing3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Learning Primary Outcome 3 measured with Deterministic Reversal Learning test: Percent correct per stage3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Emotion Recognition Primary Outcome 2 measured with EMOTICOM Emotion Recognition Task: Affective bias for D'3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Positron emission tomography (PET) Imaging: Cerebral [11C]SB207145 PET binding.3 Years

Collected before and after participant's intervention.

Neural Activations and Correlations measured with functional magnetic resonance imaging (fMRI) paradigm named Cohabit3 Years

Imaging outcomes will be Family-Wise Error (FWE) corrected using Random Field Theory as implemented in SPM12Co-habit fMRI paradigm Imaging outcomes will be FWE corrected using Random Field Theory as implemented in SPM12.

Social Cognition Primary Outcome 1 measured with EMOTICOM Moral Emotions Task: Agent Guilt Score3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Social Cognition Primary Outcome 2 measured with EMOTICOM Moral Emotions Task: Agent Shame Score3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. The false discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Emotion Recognition Primary Outcome 4 measured with EMOTICOM Emotion Recognition task: D'Prime for emotion recognition3 Years

Emotion Recognition Task. Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Memory Primary Outcome 1 measured with CANTAB Paired Associates Learning: Total Errors Adj3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Biofluids3 Years

Serum Escitalopram levels

Neural Activations and Correlations measured with functional magnetic resonance imaging (fMRI) paradigm named Slip of Actions3 Years

Imaging outcomes will be Family-Wise Error (FWE) corrected using Random Field Theory as implemented in SPM12.

Diffusion Tensor Imaging MRI3 Years
Habit formation outcome 1: response times for each day of training3 Years

Daily app training paradigm

Habit formation outcome 2: mean errors per sequence and moves3 Years

Daily app training paradigm

Neural Activations and Correlations measured with functional magnetic resonance imaging (fMRI) paradigm named Faces3 Years

Imaging outcomes will be Family-Wise Error (FWE) corrected using Random Field Theory as implemented in SPM12.

Resting State fMRI3 Years

Imaging outcomes will be Family-Wise Error (FWE) corrected using Random Field Theory as implemented in SPM12.

Structural Voxel-based morphometry (VBM) MRI3 Years

Imaging outcomes will be Family-Wise Error (FWE) corrected using Random Field Theory as implemented in SPM12.

Secondary Outcome Measures
NameTimeMethod
Learning Secondary Outcome 2 measured with Probability Reversal Learning test: Stage 1 Reward/Punishment learning3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Learning Secondary Outcome 4 measured with Probability Reversal Learning test: Stage 2 Reward-Stay/ Lose-Shift behaviour3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Learning Secondary Outcome 5 measured with Probability Reversal Learning test: Stage 2 Reward/Punishment learning3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Learning Secondary Outcome 7 measured with Deterministic Reversal Learning test: Reward-Stay/ Lose-Shift behaviour3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Behavioural outcomes with Faces and geometric figure discrimination Outcome 2 measured with fMRI faces paradigm: Response Speed3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Learning Secondary Outcome 6 measured with Probability Reversal Learning test: Stage 2. Stimulus Stickiness3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Learning Secondary Outcome 1 measured with Probability Reversal Learning test: Stage 1 Reward-Stay/Lose-Shift behaviour3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Learning Secondary Outcome 3 measured with Probability Reversal Learning test: Stage 1. Stimulus Stickiness3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Inhibition Secondary Outcome 2 measured with Interleaved Stop Signal Task/Go-NoGo: Go omission error rate3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Emotion Recognition Secondary Outcome 3 measured with EMOTICOM Emotion Recognition Task: Affective bias for Hit Rate3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Flexibility Secondary Outcome 2 measured with Sequential Model-Based/Model-Free test: Exploration3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Flexibility Secondary Outcome 3 measured with Sequential Model-Based/Model-Free test: Stimulus Stickiness3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Flexibility Secondary Outcome 5 measured with 3Dimensional Intra/Extra Dimensional Shift test: Pre Extra Dimension Set Errors3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Flexibility Secondary Outcome 6 measured with 3Dimensional Intra/Extra Dimensional Shift test: Latency3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Inhibition Secondary Outcome 4 measured with Interleaved Stop Signal Task/Go-NoGo: No-Go error rate3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Emotion Recognition Secondary Outcome 4 measured with EMOTICOM Emotion Recognition Task.: Hit Rate for Emotion Recognition3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Behavioural outcomes with fMRI paradigm Co-habit: accuracy and latency.3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

State and Trait Aggression Questionnaire Score3 Years
Visual Analogue Scale Score3 Years
Executive Function Secondary Outcome 1 measured with 3Dimensional Intra/Extra Dimensional Shift test: Total Errors Adjusted3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Memory Outcome 2 measured with Letter-number sequencing test: Total score3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Risky Decision Making Outcome 3 measured with EMOTICOM Cambridge Gamble Task: Overall Proportion Bet3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Risky Decision Making Outcome 4 measured with EMOTICOM Cambridge Gamble Task: Deliberation Time3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Interpersonal Reactivity Index (IRI) Score3 Years
Flexibility Secondary Outcome 1 measured with Sequential Model-Based/Model-Free test: Proportion of Stays3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Inhibition Secondary Outcome 1 measured with Interleaved Stop Signal Task/Go-NoGo: Go reaction time3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Inhibition Secondary Outcome 3 measured with Interleaved Stop Signal Task/Go-NoGo: Go commission error rate3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Emotion Recognition Secondary Outcome 1 measured with EMOTICOM Intensity Morphing Task: Detection threshold increasing3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Emotion Recognition Secondary Outcome 2 measured with EMOTICOM Intensity Morphing Task: Affective bias in increasing condition3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Memory Primary outcome 3 measured with Verbal Affective Memory Test-26: Latent variable model of the association between positive, negative and neutral word recall and 5-HT4R binding3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Flexibility Secondary Outcome 4 measured with Sequential Model-Based/Model-Free test: Learning rate3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Faces and geometric figure discrimination Outcome 1 measured with fMRI faces paradigm: Accuracy3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Behavioural outcomes with fMRI paradigm slip of Actions : accuracy and latency3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Psychomotor Speed Outcome 1 measured with CANTAB Reaction Time Task: Simple reaction time3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Obsessive- Compulsive Inventory (OCI)- state Score3 Years
Risky Decision Making Outcome Outcome 1 measured with EMOTICOM Cambridge Gamble Task: Quality of Decision Making3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Risky Decision Making Outcome 2 measured with EMOTICOM Cambridge Gamble Task: Risk Adjustment3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Barratt Impulsiveness Scale-State Score3 Years
Memory Outcome 1 measured with CANTAB Paired Associates Learning test: First Trial Memory Score3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain.

Obsessive- Compulsive Inventory- trait Score3 Years
State-Trait Anxiety Inventory Scale Score3 Years

Contain 40-items

Intelligence Quotient (IQ) outcome 1 measured with Reynolds Intellectual assessment Scales subtest "guess what" and "what does not fit": Total age adjusted score3 Years

Outcome variables have been grouped a priori into carefully defined cognitive domains. False discovery rate (FDR) correction, for multiple comparisons, using the Benjamini-Hochberg procedure will be applied to the outcomes within each cognitive domain

Brief Symptom Inventory (BSI) Score3 Years
Pittsburgh Sleep Quality Index Score3 Years
Profile of Mood State Score3 Years
Beck Depression Inventory-II Score3 Years

Contain 21-items, scored on a scale value of 0 to 3

Trial Locations

Locations (1)

Neurobiology Research Unit, Rigshospitalet

🇩🇰

Copenhagen, Denmark

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