Brain Network Dynamics of Depression During Esketamine Treatment

Study Overview
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Brief Summary
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This is a monocentric, observational clinical trial investigating the effect of Esketamine on brain network activity and a belief updating task in people with depression. We investigate the immediate and the long-term effect (approx. 8 weeks) of Esketamine on EEG signals, pupillometry and belief updating and the relation of those effects on depressive symptomatology.

Detailed Description
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The FDA approved the S-enantiomer of Ketamine in a nasal spray formulation (Esketamine, Spravato) in 2019 for treatment resistant depression in conjunction with an oral antidepressant. Albeit showing impressive short term clinical effects, the neurophysiological mechanism leading to clinical improvements are not understood. The investigators aim to add missing knowledge about the network dynamics of Esketamine in depression. Besides changes of neural signatures, Esketamine might impact cognitive processes like belief updating. Previous studies have shown that people update their expectations of future life events after receiving novel information. The Belief Updating Task (BUT) measures this belief update in reaction to new information. Healthy individuals have been shown to update their beliefs optimistically, making larger changes in their expectations in response to good news. Individuals with depression lack this optimistic belief update bias. Therefore, the investigators also aim to examine if Esketamine treatment reinstates the optimistic bias, how those changes are mediated by neurophysiological changes during the task and if a change in belief updated is related to a change of depressive symptoms. The first session takes place at the start of the Esketamine treatment period, whereas the second experimental session is conducted closer to the end of the treatment period. In both experimental sessions, EEG/pupillometry and cognitive measurements are taken before and after Esketamine administration. Analyses will assess pre/post Esketamine effects within a session and between two sessions.

Official Title
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Brain Network Dynamics of Depression During Esketamine Treatment

Conditions
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Depressive Disorder, Major

Intervention / Treatment
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* Drug: Esketamine nasal spray


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Major Depressive Disorder Receiving Esketamine nasal spray treatment for depression Ability to understand study procedures and sign an informed consent. Exclusion Criteria: None

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 99 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Treatment Resistant Depression + Esketamine Treatment<br>This is a group of individuals with treatment resistant depression receiving Esketamine treatment as prescribed by their physician during outpatient appointments over several weeks at the Interventional Psychiatry outpatient clinic at University of North Carolina at Chapel Hill (UNC). After signing the informed consent, electroencephalogram (EEG) will be recorded before and after Esketamine administration by the attending physician. The participant will perform a cognitive task before and after the Esketamine administration as well as complete self-scored questionnaire regarding depressive symptoms, treatment expectation and Esketamine side-effects. Clinical information like the duration of episode, medication or clinician-rated depression scores will be retrieved from the charting system. | Drug: Esketamine nasal spray<br>* This is an observational study. The Esketamine nasal spray is administered by the attending physician during a regular treatment appointment at the Interventional Psychiatry Clinic. Esketamine dosages may range between 28-84mg. The study does not interfere with the individual treatment plan in any way.<br>* Other names: Spravato;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Belief Updating in Session 1 | Participants rate the likelihood of a negative life event happening to them (E1) and their confidence in the estimate (C1). They are given a base rate (BR), described as the average lifetime probability of that event happening to someone with the same demographics. Participants will then again rate how likely the event could happen to them personally (E2). Outcome variables: update = |E2 - E1| and estimation error (ER) = |E1 - BR| News: good news (BR< E1) or bad news (BR>E1) trials. Within session relationships between update, C1, ER and covariates will be investigated using linear mixed models (LMMs) using an iterative model comparison process. The basic model will include fixed effect of News and a random intercept for individuals (id or ID). Potential covariates likely include ER, C1, the Revised Life Orientation Test (LOT-R), Ketamine Side Effect Tool (KSET), and scores of depression severity. | 10 minutes before Esketamine application compared to 2 hours after Esketamine application | 
| Change in Belief Updating in Session 2 | Participants rate the likelihood of a negative life event happening to them (E1) and their confidence in the estimate (C1). They are given a base rate (BR), described as the average lifetime probability of that event happening to someone with the same demographics. Participants will then again rate how likely the event could happen to them personally (E2). Outcome variables: update = |E2 - E1| and estimation error (ER) = |E1 - BR| News: good news (BR< E1) or bad news (BR>E1) trials. Within session relationships between update, C1, ER and covariates will be investigated using linear mixed models (LMMs) using an iterative model comparison process. The basic model will include fixed effect of News and a random intercept for ID (individuals). Potential covariates likely include ER, C1, the Revised Life Orientation Test (LOT-R), Ketamine Side Effect Tool (KSET), and scores of depression severity. | 10 minutes before Esketamine application compared to 2 hours after Esketamine application | 
| Change in Confidence in Beliefs Questionnaire in Session 1 | Confidence in Beliefs Questionnaire investigates the strengths of belief in statements about the participant and about someone close to them. Participants rate how certain they are about each belief, higher values imply higher certainty Beliefs about oneself: 12 items (6 positive, 6 negative), Likert Scale 0 to 100, participants make a mark on a line Beliefs about others: 12 items (6 positive, 6 negative), Likert Scale 0 to 100, participants make a mark on a line | 30 minutes before Esketamine application compared to 2 hours after Esketamine application | 
| Change in Confidence in Beliefs Questionnaire in Session 2 | Confidence in Beliefs Questionnaire investigates the strengths of belief in statements about the participant and about someone close to them. Participants rate how certain they are about each belief, higher values imply higher certainty Beliefs about oneself: 12 items (6 positive, 6 negative), Likert Scale 0 to 100, participants make a mark on a line Beliefs about others: 12 items (6 positive, 6 negative), Likert Scale 0 to 100, participants make a mark on a line | 30 minutes before Esketamine application compared to 2 hours after Esketamine application | 
| Change of Ketamine Side Effect Tool (KSET) in Session 1 | Semi-structured interview to assess side effects of ketamine Each item is scores from 0 (=never) to 3 (= severe) points Sum scores and individual item scores can be analyzed. | 5 minutes before Esketamine application, and 50, 95, and 130 minutes after Esketamine application | 
| Change of Ketamine Side Effect Tool (KSET) in Session 2 | Semi-structured interview to assess side effects of ketamine Each item is scores from 0 (=never) to 3 (= severe) points Sum scores and individual item scores can be analyzed. | 5 minutes before Esketamine application, and 50, 95, and 130 minutes after Esketamine application | 
| Change in Mood Likert Scale in Session 1 | Likert Scales range from 0 to 100 Participants make a mark on a line (left end = 0, right end = 100) | 5 minutes before Esketamine application, and 15, 35, 50, 75, 95, and 130 minutes after Esketamine application | 
| Change in Mood Likert Scale in Session 2 | Likert Scales range from 0 to 100 Participants make a mark on a line (left end = 0, right end = 100) | 5 minutes before Esketamine application, and 15, 35, 50, 75, 95, and 130 minutes after Esketamine application | 
| Change in Quality of Life Enjoyment and Satisfaction Questionnaire, short version (Q-LES-Q-SF) | Change in Q-LES-Q-SF between Session 1 and Session 2 Q-LES-Q-SF is a brief, self-scoring quality of life rating scale. Maximum percentage is 100%. Higher values imply higher quality of life | Session 1 and session 2 | 
| Change in Patient Health Questionnaire (PHQ-9) | Change in PHQ-9 between Session 1 and Session 2 PHQ-9 is a brief, self-scoring depression rating scale. Higher values imply a higher depression severity. Cut-off for depression is considered >4 PHQ-9 points | Session 1 and session 2 | 
| Change in Hamilton Depression Rating Scale (HDRS) | Change in HDRS-17 between Session 1 and Session 2 HDRS-17 is the most established depression rating scale. Higher values imply a higher depression severity. Cut-off for depression is considered >8 HDRS-17 points | Session 1 and session 2 | 
| Change of Resting State EEG - Power in Session 1 | Changes in oscillatory power within an experimental session pre/post Esketamine application Power will be analyzed in canonical frequency bands (e.g. alpha, beta, gamma, delta, theta) | 5 minutes before Esketamine application, and 15, 35, 50, 75, 95, and130 minutes after Esketamine application | 
| Change of Resting State EEG - Power in Session 2 | Changes in oscillatory power within an experimental session pre/post Esketamine application Power will be analyzed in canonical frequency bands (e.g. alpha, beta, gamma, delta, theta) | 5 minutes before Esketamine application, and 15, 35, 50, 75, 95, and130 minutes after Esketamine application | 
| Change of Resting State EEG - Connectivity in Session 1 | - Changes in functional connectivity in canonical frequency band within an experimental session pre/post Esketamine application | 5 minutes before Esketamine application, and 15, 35, 50, 75, 95, and 130 minutes after Esketamine application | 
| Change of Resting State EEG - Connectivity in Session 2 | - Changes in functional connectivity in canonical frequency band within an experimental session pre/post Esketamine application | 5 minutes before Esketamine application, and 15, 35, 50, 75, 95, and 130 minutes after Esketamine application | 
| Change of Resting State EEG - Source in Session 1 | - Changes in spatial distribution and source of electric activity in canonical frequency band within an experimental session pre/post Esketamine application | 5 minutes before Esketamine application, and 15, 35, 50, 75, 95, and 130 minutes after Esketamine application | 
| Change of Resting State EEG - Source in Session 2 | - Changes in spatial distribution and source of electric activity in canonical frequency band within an experimental session pre/post Esketamine application | 5 minutes before Esketamine application, and 15, 35, 50, 75, 95, and 130 minutes after Esketamine application | 
| Change of Resting State EEG - Aperiodic Signal in Session 1 | - Changes in slope and offset of the aperiodic EEG signal within an experimental session pre/post Esketamine application | 5 minutes before Esketamine application, and 15, 35, 50, 75, 95, and 130 minutes after Esketamine application | 
| Change of Resting State EEG - Aperiodic Signal in Session 2 | - Changes in slope and offset of the aperiodic EEG signal within an experimental session pre/post Esketamine application | 5 minutes before Esketamine application, and 15, 35, 50, 75, 95, and 130 minutes after Esketamine application | 
| Change of Resting State EEG - Entropy in Session 1 | - Changes of entropy measured in Lempel-Ziv Complexity and mutual information within an experimental session pre/post Esketamine application | 5 minutes before Esketamine application, and 15, 35, 50, 75, 95, and 130 minutes in after Esketamine application | 
| Change of Resting State EEG - Entropy in Session 2 | - Changes of entropy measured in Lempel-Ziv Complexity and mutual information within an experimental session pre/post Esketamine application | 5 minutes before Esketamine application, and 15, 35, 50, 75, 95, and 130 minutes after Esketamine application | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Task EEG - Event Related Potential (ERP) in Session 1 | ERP after presentation of baseline will be calculated for trials with good/bad news, low/high estimation error and low/high confidence (-500 to 2000ms) We will analyze the amplitude and spatial distribution of canonical ERP such as N1,N2, P3 and late positive potential | 30 minutes before Esketamine application and 100 minutes after Esketamine application | 
| Change in Task EEG - Event Related Potential (ERP) in Session 2 | ERP after presentation of baseline will be calculated for trials with good/bad news, low/high estimation error and low/high confidence (-500 to 2000ms) We will analyze the amplitude and spatial distribution of canonical ERP such as N1,N2, P3 and late positive potential | 30 minutes before Esketamine application and 100 minutes after Esketamine application | 
| Change in Task EEG - Time Frequency Analysis in Session 1 | Using wavelet convolution we will conduct a time-frequency analysis for good/bad news, low/high estimation error and low/high confidence Time of interest -500 to 2000ms after base rate presentation Frequency of interest will be 2-40Hz | 30 minutes before Esketamine application and 100 minutes after Esketamine application | 
| Change in Task EEG - Time Frequency Analysis in Session 2 | Using wavelet convolution we will conduct a time-frequency analysis for good/bad news, low/high estimation error and low/high confidence Time of interest -500 to 2000ms after base rate presentation Frequency of interest will be 2-40 Hertz (Hz) | 30 minutes before Esketamine application and 100 minutes after Esketamine application | 
| Change in Pupillometry in Session 1 | Pupil size during good/bad news and high/low estimation error and low/high confidence trials in the belief updating task Time-locked around the presentation of the base rate (-500 to 2000ms) | 30 minutes before Esketamine application and 100 minutes after Esketamine application | 
| Change in Pupillometry in Session 2 | Pupil size during good/bad news and high/low estimation error and low/high confidence trials in the belief updating task Time-locked around the presentation of the base rate (-500 to 2000ms) | 30 minutes before Esketamine application and 100 minutes after Esketamine application | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Esketamine, Ketamine, Belief Updating, Pupillometry, EEG