A Study of Esketamine Nasal Spray Versus Placebo Spray in Adult Participants With Treatment-resistant Depression

The MADRS is a clinician-rated scale designed to measure depression severity and detects changes due to antidepressant treatment. The scale consists of 10 items, each of which is scored from 0 (item not present or normal) to 6 (severe or continuous presence of the symptoms), for a total possible score of 60. Higher scores represent a more severe condition.

The MADRS is a clinician-rated scale designed to measure depression severity and detects changes due to antidepressant treatment. The scale consists of 10 items, each of which is scored from 0 (item not present or normal) to 6 (severe or continuous presence of the symptoms), for a total possible score of 60. Higher scores represent a more severe condition.

Percentage of responders (greater than or equal to [>=] 50 percent [%] reduction from baseline in MADRS total score) over time to the end of the 4-week DB treatment phase will be reported. The MADRS is a clinician-rated scale designed to measure depression severity and detects changes due to antidepressant treatment. The scale consists of 10 items, each of which is scored from 0 (item not present or normal) to 6 (severe or continuous presence of the symptoms), for a total possible score of 60. Higher scores represent a more severe condition.

Percentage of participants in remission (MADRS less than or equal to [<=] 10 and MADRS <= 12) over time to the end of the 4-week DB treatment phase will be reported. The MADRS is a clinician-rated scale designed to measure depression severity and detects changes due to antidepressant treatment. The scale consists of 10 items, each of which is scored from 0 (item not present or normal) to 6 (severe or continuous presence of the symptoms), for a total possible score of 60. Higher scores represent a more severe condition.

Change from baseline in CGI-S over time to the end of the 4-week DB treatment phase will be reported. The CGI-S is a clinician-rated scale that measures illness severity. The CGI has proved to be a robust measure of efficacy in many clinical drug trials and is easy and quick to administer. The CGI-S is rated on a 7-point scale, with the severity of illness scale using a range of responses from 1 (normal) through to 7 (among the most severely ill participants).

Change from baseline in MADRS total score over time to the end of the 4-week DB treatment phase will be reported. The MADRS is a clinician-rated scale designed to measure depression severity and detects changes due to antidepressant treatment. The scale consists of 10 items, each of which is scored from 0 (item not present or normal) to 6 (severe or continuous presence of the symptoms), for a total possible score of 60. Higher scores represent a more severe condition.

Change from baseline in individual MADRS item scores over time to the end of the 4-week DB treatment phase will be reported. The MADRS is a clinician-rated scale designed to measure depression severity and detects changes due to antidepressant treatment. The scale consists of 10 items, each of which is scored from 0 (item not present or normal) to 6 (severe or continuous presence of the symptoms), for a total possible score of 60. Higher scores represent a more severe condition.

Change from baseline in anhedonia symptoms over time to the end of the 4-week DB treatment phase as assessed by MADRS anhedonia factor score will be reported. The MADRS anhedonia factor is a widely used 5-item subscale of the MADRS used to specifically measure the lack of pleasure (anhedonia) in depression, combining items for apparent sadness, reported sadness, concentration difficulties, lassitude (tiredness), and inability to feel. The sum of these five items (each scored 0-6), resulting in a score from 0 to 30, with higher scores indicating more severe anhedonia. This score helps assess treatment effectiveness for anhedonia, correlates with functional improvement, and provides a deeper look beyond the total depression score, showing significant clinical relevance in major depressive disorder (MDD) trials.

Change from baseline in patient-reported anhedonia symptoms over time to the end of the 4-week DB treatment phase as assessed by PHQ-9 item 1 score (little interest/pleasure in things) will be reported. The PHQ-9 is a participant-reported outcome measure that will be used to assess depressive symptoms. The scale scores each of the 9 symptom domains of the diagnostic and statistical manual of mental disorders (5th edition) (DSM-5) MDD criteria and it has been used both as a screening tool and a measure of response to treatment for depression. Each item is rated on a 4-point scale (0=not at all, 1=several days, 2=more than half the days, and 3=nearly every day).

Change from baseline in PHQ-9 total score over time to the end of the 4-week DB treatment phase will be reported. The PHQ-9 is a participant-reported outcome measure that will be used to assess depressive symptoms. The scale scores each of the 9 symptom domains of the DSM-5 MDD criteria and it has been used both as a screening tool and a measure of response to treatment for depression. Each item is rated on a 4-point scale (0=not at all, 1=several days, 2=more than half the days, and 3=nearly every day). The participant's item responses are summed to provide a total score (range of 0 to 27) with higher scores indicating greater severity of depressive symptoms.

Percentage of responders (>= 50% reduction from baseline in PHQ-9 total score) over time to the end of the 4-week DB treatment phase will be reported. The PHQ-9 is a participant-reported outcome measure that will be used to assess depressive symptoms. The scale scores each of the 9 symptom domains of the DSM-5 MDD criteria and it has been used both as a screening tool and a measure of response to treatment for depression. Each item is rated on a 4-point scale (0=not at all, 1=several days, 2=more than half the days, and 3=nearly every day). The participant's item responses are summed to provide a total score (range of 0 to 27) with higher scores indicating greater severity of depressive symptoms.

Percentage of participants in remission (PHQ-9 total score < 5) over time to the end of the 4-week DB treatment phase will be reported. The PHQ-9 is a participant-reported outcome measure that will be used to assess depressive symptoms. The scale scores each of the 9 symptom domains of the DSM-5 MDD criteria and it has been used both as a screening tool and a measure of response to treatment for depression. Each item is rated on a 4-point scale (0=not at all, 1=several days, 2=more than half the days, and 3=nearly every day). The participant's item responses are summed to provide a total score (range of 0 to 27) with higher scores indicating greater severity of depressive symptoms.

Percentage of responders (>= 50% reduction from baseline in MADRS total score) over time to the end of the OL treatment phase will be reported. The MADRS is a clinician-rated scale designed to measure depression severity and detects changes due to antidepressant treatment. The scale consists of 10 items, each of which is scored from 0 (item not present or normal) to 6 (severe or continuous presence of the symptoms), for a total possible score of 60. Higher scores represent a more severe condition.

Percentage of participants in remission (MADRS <= 10 and MADRS <= 12) over time to the end of the OL treatment phase will be reported. The MADRS is a clinician-rated scale designed to measure depression severity and detects changes due to antidepressant treatment. The scale consists of 10 items, each of which is scored from 0 (item not present or normal) to 6 (severe or continuous presence of the symptoms), for a total possible score of 60. Higher scores represent a more severe condition.

Change from baseline in CGI-S over time to the end of the OL treatment phase will be reported. The CGI-S is a clinician-rated scale that measures illness severity. The CGI has proved to be a robust measure of efficacy in many clinical drug trials and is easy and quick to administer. The CGI-S is rated on a 7-point scale, with the severity of illness scale using a range of responses from 1 (normal) through to 7 (among the most severely ill participants).

Change from baseline in MADRS total score over time to the end of the OL treatment phase will be reported. The MADRS is a clinician-rated scale designed to measure depression severity and detects changes due to antidepressant treatment. The scale consists of 10 items, each of which is scored from 0 (item not present or normal) to 6 (severe or continuous presence of the symptoms), for a total possible score of 60. Higher scores represent a more severe condition.

Change from baseline in individual MADRS item scores over time to the end of the OL treatment phase will be reported. The MADRS is a clinician-rated scale designed to measure depression severity and detects changes due to antidepressant treatment. The scale consists of 10 items, each of which is scored from 0 (item not present or normal) to 6 (severe or continuous presence of the symptoms), for a total possible score of 60. Higher scores represent a more severe condition.

Change from baseline in anhedonia symptoms over time to the end of the OL treatment phase as assessed by MADRS anhedonia factor score will be reported. The MADRS is a clinician-rated scale designed to measure depression severity and detects changes due to antidepressant treatment. The scale consists of 10 items, each of which is scored from 0 (item not present or normal) to 6 (severe or continuous presence of the symptoms), for a total possible score of 60. Higher scores represent a more severe condition.

Change from baseline in patient-reported anhedonia symptoms over time to the end of the OL treatment phase as assessed by PHQ-9 item 1 score will be reported. The PHQ-9 is a participant-reported outcome measure that will be used to assess depressive symptoms. The scale scores each of the 9 symptom domains of the DSM-5 MDD criteria and it has been used both as a screening tool and a measure of response to treatment for depression. Each item is rated on a 4-point scale (0=not at all, 1=several days, 2=more than half the days, and 3=nearly every day). The participant's item responses are summed to provide a total score (range of 0 to 27) with higher scores indicating greater severity of depressive symptoms.

Change from baseline in PHQ-9 total score over time to the end of the OL treatment phase will be reported. The PHQ-9 is a participant-reported outcome measure that will be used to assess depressive symptoms. The scale scores each of the 9 symptom domains of the DSM-5 MDD criteria and it has been used both as a screening tool and a measure of response to treatment for depression. Each item is rated on a 4-point scale (0=not at all, 1=several days, 2=more than half the days, and 3=nearly every day). The participant's item responses are summed to provide a total score (range of 0 to 27) with higher scores indicating greater severity of depressive symptoms.

Percentage of responders (>= 50% reduction from baseline in PHQ-9 total score) over time to the end of the OL treatment phase will be reported. The PHQ-9 is a participant-reported outcome measure that will be used to assess depressive symptoms. The scale scores each of the 9 symptom domains of the DSM-5 MDD criteria and it has been used both as a screening tool and a measure of response to treatment for depression. Each item is rated on a 4-point scale (0=not at all, 1=several days, 2=more than half the days, and 3=nearly every day). The participant's item responses are summed to provide a total score (range of 0 to 27) with higher scores indicating greater severity of depressive symptoms.

Percentage of participants in remission (PHQ-9 total score < 5) over time to the end of the OL treatment phase will be reported. The PHQ-9 is a participant-reported outcome measure that will be used to assess depressive symptoms. The scale scores each of the 9 symptom domains of the DSM-5 MDD criteria and it has been used both as a screening tool and a measure of response to treatment for depression. Each item is rated on a 4-point scale (0=not at all, 1=several days, 2=more than half the days, and 3=nearly every day). The participant's item responses are summed to provide a total score (range of 0 to 27) with higher scores indicating greater severity of depressive symptoms.

Number of participants who experience abnormally low blood oxygen saturation will be reported.

An AE is any untoward medical occurrence in a clinical study participant administered a pharmaceutical (investigational or non-investigational) product. An AE does not necessarily have a causal relationship with the intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal finding), symptom, or disease temporally associated with the use of a medicinal (investigational or non-investigational) product, whether or not related to that medicinal (investigational or non-investigational) product. TEAEs are defined as any adverse event occurring at or after the administration of study intervention.

The C-SSRS is a clinical interview providing a summary of both ideation and behavior that can be administered during any evaluation or risk assessment to identify the level and type of suicidality present. The C-SSRS can also be used during treatment to monitor for clinical worsening.

The CADSS will be administered to assess treatment-emergent dissociative symptoms. It comprises 23 subjective items, divided into 3 components: depersonalization (items 3-7, 20, 23), derealization (items 1-2, 8-13, 16-19, 21) and amnesia (items 14-15, 22). Participant's responses are coded on a 5-point scale (0 = "Not at all" through to 4 = "Extremely"). A higher score indicates a more severe condition.

Number of participants with abnormalities in physical examination will be reported.

Number of participants with abnormalities in vital signs (blood pressure, pulse/heart rate measurements, and temperature) will be reported.

Number of participants reporting clinically meaningful changes in body weight will be reported.

Number of participants with abnormalities in 12-lead ECG will be reported.

Number of participants who experience abnormally low blood oxygen saturation will be reported.

An AE is any untoward medical occurrence in a clinical study participant administered a pharmaceutical (investigational or non-investigational) product. An AE does not necessarily have a causal relationship with the intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal finding), symptom, or disease temporally associated with the use of a medicinal (investigational or non-investigational) product, whether or not related to that medicinal (investigational or non-investigational) product. TEAEs are defined as any adverse event occurring at or after the administration of study intervention.

The C-SSRS is a clinical interview providing a summary of both ideation and behavior that can be administered during any evaluation or risk assessment to identify the level and type of suicidality present. The C-SSRS can also be used during treatment to monitor for clinical worsening.

Number of participants with abnormalities in vital signs (blood pressure, pulse/heart rate measurements, and temperature) will be reported.

Number of participants reporting clinically meaningful changes in body weight will be reported.

Number of participants with abnormalities in 12-lead ECG will be reported.

The PWC-20 is a 20-item simple and accurate method to assess potential development of discontinuation symptoms after stopping of study medication. The PWC-20 is a reliable and sensitive instrument for the assessment of discontinuation symptoms.