Participants meeting any of the following criteria were determined as having major depressive disorder symptom re-emergence: 1) a Montgomery-Asberg Depression Rating Scale (MADRS) total score greater ≥14 or a Clinical Global Impressions of Severity (CGI-S) increase of 2 or more points from Week 18 at 2 consecutive visits or 2) discontinuation due to lack of efficacy/worsening of depression/suicidality. Time from randomization to the first visit at which the participant met the reemergence criteria was calculated. The percentage of participants who meet criteria was estimated using the Kaplan-Meier product limit method. The MADRS is a rating scale for severity of depressive mood symptoms and has a 10-item checklist with items rated on a scale of 0-6, for a total score range of 0 (low severity) to 60 (high severity). CGI-S measures severity of depression at the time of assessment compared with the start of treatment. Scores range from 1 (normal, not at all ill) to 7 (extremely ill).

All randomized participants.

Participants meeting any of the following criteria were determined as having major depressive disorder symptom re-emergence: 1) a Montgomery-Asberg Depression Rating Scale (MADRS) total score greater ≥14 or a Clinical Global Impressions of Severity (CGI-S) increase of 2 or more points from Week 18 at 2 consecutive visits or 2) discontinuation due to lack of efficacy/worsening of depression/suicidality. The percentage of participants with re-emergence of depressive symptoms was calculated by dividing the number of participants who meet any of the criteria by the total number of participants analyzed, multiplied by 100. The MADRS is a rating scale for severity of depressive mood symptoms and has a 10-item checklist with items rated on a scale of 0-6, for a total score range of 0 (low severity) to 60 (high severity). CGI-S measures severity of depression at the time of assessment compared with the start of treatment. Scores range from 1 (normal, not at all ill) to 7 (extremely ill).

All randomized participants.

Montgomery-Asberg Depression Rating Scale (MADRS) is a rating scale for severity of depressive mood symptoms. The MADRS has a 10-item checklist (sadness [apparent], sadness [reported], inner tension, reduced sleep, reduced appetite, concentration difficulties, lassitude, inability to feel, pessimistic thoughts, and suicidal thoughts). Items are rated on a scale of 0-6, for a total score range of 0 (low severity of depressive symptoms) to 60 (high severity of depressive symptoms). Least Squares (LS) means were calculated using a mixed model repeated measures (MMRM) analysis which includes terms for the fixed categorical effects of treatment, country, visit, and treatment-by-visit interaction, as well as the continuous, fixed covariates of baseline MADRS total score (individual item score) and baseline MADRS total score (individual item score)-by-visit interaction.

All randomized participants who have non-missing values at the time of randomization and at least one post-randomization value.

The Hospital Anxiety and Depression Scale (HADS) is a 14-item questionnaire with 2 subscales: anxiety and depression. Each item is rated on a 4-point scale (0-3), giving maximum scores of 21 for anxiety and depression. Scores of 11 or more on either subscale are considered to be a 'significant' case of psychological morbidity, while scores of 8-10 represent 'borderline' and 0-7 represent 'normal'. Least Squares (LS) means were calculated using a mixed model repeated measures (MMRM) analysis which included terms for the fixed categorical effects of treatment, country, visit, and treatment-by-visit interaction, as well as the continuous, fixed covariates of baseline subscale score and baseline subscale score-by-visit interaction.

All randomized participants who have non-missing values at the time of randomization and at least one post-randomization value.

The Clinical Global Impression of Severity (CGI-S) instrument is used to record the severity of mental illness at the time of assessment. Scores range from 1 (normal, not at all ill) to 7 (among the most extremely ill participants). Least Squares (LS) means were calculated using a mixed model repeated measures (MMRM) analysis which included terms for the fixed categorical effects of treatment, country, visit, and treatment-by-visit interaction, as well as the continuous, fixed covariates of baseline CGI-S score and baseline CGI-S score-by-visit interaction.

All randomized participants who have non-missing values at the time of randomization and at least one post-randomization value.

The FAsD is a 13-item participant-rated scale. Items 1-6 ask how often participants experience different aspects of fatigue with responses from 1 (never) to 5 (always). Items 7-13 ask how often fatigue impacts various aspects of the participant's lives with responses from 1 (not at all) to 5 (very much). The experience subscale score is derived by taking the mean of Items 1-6. The impact subscale score is derived by taking the mean of applicable Items 7-13. The average score is the mean of applicable Items 1-13. Item 12 applies only to participants with a spouse or significant other and Item 13 applies to participants who had a job or who went to school. Least Squares (LS) means were calculated using a mixed model repeated measures (MMRM) analysis which included terms for the fixed categorical effects of treatment, country, visit, and treatment-by-visit interaction, as well as the continuous, fixed covariates of baseline score and baseline score-by-visit interaction.

All randomized participants who have non-missing values at the time of randomization and at least one post-randomization value.

The Sheehan Disability Scale (SDS) is completed by the participant and used to assess the effect of the participant's symptoms on their work (work/school impairment score), social life (social life/leisure activities impairment score), and family life (family life/home responsibilities impairment score). Each item is measured on a 0 (not at all) to 10 (extremely) point scale with higher values indicating greater disruption. Least Squares (LS) means were calculated using a mixed model repeated measures (MMRM) analysis which included terms for the fixed categorical effects of treatment, country, visit, and treatment-by-visit interaction, as well as the continuous, fixed covariates of baseline score and baseline score-by-visit interaction

All randomized participants who have non-missing values at the time of randomization and at least one post-randomization value.

The EQ-5D, a health-related, quality-of-life instrument, contains 2 parts: a health status profile and a visual analog scale (VAS). The profile allows participants to rate their health state in 5 health domains: mobility, self-care, usual activities, pain/discomfort, and mood using a 3-level scale (no problem, some problems, and major problems). These dimensions are converted into weighted health-state index scores according to United States (US) and United Kingdom (UK) population-based algorithms. The US and UK based index scores range from -0.11 to 1.0 (where a score of 1.0 indicates perfect health) and from -0.59 (severe problems in all 5 dimensions) to 1.0 (no problem in any dimension), respectively. The VAS consists of participants rating their current health state from 0 (worst imaginable health state) to 100 (best imaginable health). Least Squares (LS) means were calculated using analysis of covariance (ANCOVA) model with main effects of treatment, country, and baseline score.

All randomized participants who have non-missing values at the time of randomization and at least one post-randomization value. Last observation carried forward (LOCF) methodology was used.

The Columbia-Suicide Severity Rating Scale (C-SSRS) captures occurrence, severity, and frequency of suicide-related thoughts and behaviors. Suicidal ideation is defined as a "yes" answer to any 1 of 5 suicidal ideation questions, which includes a wish to be dead and 4 different categories of active suicidal ideation. Suicidal behavior is defined as a "yes" answer to any of 5 suicidal behavior questions: preparatory acts or behavior, aborted attempt, interrupted attempt, actual attempt, and completed suicide. Suicidal ideation and behavior are defined as treatment-emergent (TE) if not present during the period up through randomization. A summary of serious and other non-serious adverse events regardless of causality is located in the Reported Adverse Event module.

All randomized participants who have non-missing values at the time of randomization and at least one post-randomization value.

Arizona Sexual Experiences (ASEX) Questionnaire is a 5-item rating scale that quantifies sex drive, arousal, vaginal lubrication/penile erection, ability to reach orgasm, and satisfaction from orgasm. Each item is rated from 1 (extremely) to 6 (no/never). Possible total scores ranged from 5 to 30, with the higher scores indicating more sexual dysfunction. Least Squares (LS) means were calculated using a mixed model repeated measures (MMRM) analysis which included terms for the fixed categorical effects of treatment, country, visit, treatment-by-visit interaction, as well as the continuous, fixed covariates of baseline ASEX total score and baseline ASEX total score-by-visit interaction.

All randomized participants who have non-missing values at the time of randomization and at least one post-randomization value.

Massachusetts General Hospital Cognitive and Physical Functioning Questionnaire (CPFQ) is a 7-item participant-rated questionnaire pertaining to a participant's cognitive and physical well-being. It assesses motivation, wakefulness, energy, focus, recall, word-finding difficulty, and mental acuity. Each item is scored on a 6-point scale ranging from 1 (greater than normal) to 6 (totally absent). Total score is reported and ranges from 7 to 42, with higher scores indicating greater impairment. Least Squares (LS) means were calculated using a mixed model repeated measures (MMRM) analysis which included terms for the fixed categorical effects of treatment, country, visit, and treatment-by-visit interaction, as well as the continuous, fixed covariates of baseline CPFQ total score and baseline CPFQ total score-by-visit interaction.

All randomized participants who have non-missing values at the time of randomization and at least one post-randomization value.

Montgomery-Asberg Depression Rating Scale (MADRS) is a rating scale for severity of depressive mood symptoms. The MADRS has a 10-item checklist (sadness [apparent], sadness [reported], inner tension, reduced sleep, reduced appetite, concentration difficulties, lassitude, inability to feel, pessimistic thoughts, and suicidal thoughts). Items are rated on a scale of 0-6, for a total score range of 0 (low severity of depressive symptoms) to 60 (high severity of depressive symptoms).

All participants who have non-missing values at baseline and at least one post-baseline value. Last observation carried forward (LOCF) methodology was used.

Montgomery-Asberg Depression Rating Scale (MADRS) is a rating scale for severity of depressive mood symptoms. The MADRS has a 10-item checklist (sadness [apparent], sadness [reported], inner tension, reduced sleep, reduced appetite, concentration difficulties, lassitude, inability to feel, pessimistic thoughts, and suicidal thoughts). Items are rated on a scale of 0-6, for a total score range of 0 (low severity of depressive symptoms) to 60 (high severity of depressive symptoms).

All participants who have non-missing values at Week 8 and at least one post-Week 8 value. Last observation carried forward (LOCF) methodology was used.

The Hospital Anxiety and Depression Scale (HADS) is a 14-item questionnaire with 2 subscales: anxiety and depression. Each item is rated on a 4-point scale (0-3), giving maximum scores of 21 for anxiety and depression. Scores of 11 or more on either subscale were considered to be a 'significant' case of psychological morbidity, while scores of 8-10 represent 'borderline' and 0-7 represent 'normal'.

All participants who have non-missing values at baseline and at least one post-baseline value. Last observation carried forward (LOCF) methodology was used.

The Hospital Anxiety and Depression Scale (HADS) is a 14-item questionnaire with 2 subscales: anxiety and depression. Each item is rated on a 4-point scale (0-3), giving maximum scores of 21 for anxiety and depression. Scores of 11 or more on either subscale are considered to be a 'significant' case of psychological morbidity, while scores of 8-10 represent 'borderline' and 0-7 represent 'normal'.

All participants who have non-missing values at Week 8 and at least one post-Week 8 value. Last observation carried forward (LOCF) methodology was used.

The Clinical Global Impression of Severity (CGI-S) instrument is used to record the severity of mental illness at the time of assessment. Scores range from 1 (normal, not at all ill) to 7 (among the most extremely ill participants).

All participants who have non-missing values at baseline and at least one post-baseline value. Last observation carried forward (LOCF) methodology was used.

The Clinical Global Impression of Severity (CGI-S) instrument is used to record the severity of mental illness at the time of assessment. Scores range from 1 (normal, not at all ill) to 7 (among the most extremely ill participants).

All participants who have non-missing values at Week 8 and at least one post-Week 8 value. Last observation carried forward (LOCF) methodology was used.

The Fatigue Associated With Depression (FAsD) is a 13-item participant-rated scale. Items 1-6 ask how often participants experience different aspects of fatigue with responses from 1 (never) to 5 (always). Items 7-13 ask how often fatigue impacts various aspects of the participant's lives with responses from 1 (not at all) to 5 (very much). The experience subscale score is derived by taking the mean of Items 1-6. The impact subscale score is derived by taking the mean of applicable Items 7-13. The average score is the mean of applicable Items 1-13. Item 12 applies only to participants with a spouse or significant other and Item 13 applies to participants who had a job or who went to school.

All participants who have non-missing values at baseline and at least one post-baseline value. Last observation carried forward (LOCF) methodology was used.

The Fatigue Associated with Depression (FAsD) is a 13-item participant-rated scale. Items 1-6 ask how often participants experience different aspects of fatigue with responses from 1 (never) to 5 (always). Items 7-13 ask how often fatigue impacts various aspects of the participant's lives with responses from 1 (not at all) to 5 (very much). The experience subscale score is derived by taking the mean of Items 1-6. The impact subscale score is derived by taking the mean of applicable Items 7-13. The average score is the mean of applicable Items 1-13. Item 12 applies only to participants with a spouse or significant other and Item 13 applies to participants who had a job or who went to school.

All participants who have non-missing values at Week 8 and at least one post-Week 8 value. Last observation carried forward (LOCF) methodology was used.

The Sheehan Disability Scale (SDS) is completed by the participant and used to assess the effect of the participant's symptoms on their work (work/school impairment score), social life (social life/leisure activities impairment score), and family life (family life/home responsibilities impairment score). Each item is measured on a 0 (not at all) to 10 (extremely) point scale with higher values indicating greater disruption.

All participants who have non-missing values at baseline and at least one post-baseline value. Last observation carried forward (LOCF) methodology was used.

The Sheehan Disability Scale (SDS) is completed by the participant and used to assess the effect of the participant's symptoms on their work (work/school impairment score), social life (social life/leisure activities impairment score), and family life (family life/home responsibilities impairment score). Each item is measured on a 0 (not at all) to 10 (extremely) point scale with higher values indicating greater disruption.

All participants who have non-missing values at Week 8 and at least one post-Week 8 value. Last observation carried forward (LOCF) methodology was used.

The EQ-5D, a health-related, quality-of-life instrument, contains 2 parts: a health status profile and a visual analog scale (VAS). The profile allows participants to rate their health state in 5 health domains: mobility, self-care, usual activities, pain/discomfort, and mood using a 3-level scale (no problem, some problems, and major problems). These dimensions are converted into weighted health-state index scores according to United States (US) and United Kingdom (UK) population-based algorithms. The US and UK based index scores range from -0.11 to 1.0 (where a score of 1.0 indicates perfect health) and from -0.59 (severe problems in all 5 dimensions) to 1.0 (no problem in any dimension), respectively. The VAS consists of participants rating their current health state from 0 (worst imaginable health state) to 100 (best imaginable health).

All participants who have non-missing values at baseline and at least one post-baseline value. Last observation carried forward (LOCF) methodology was used.

The Columbia-Suicide Severity Rating Scale (C-SSRS) captures occurrence, severity, and frequency of suicide-related thoughts and behaviors. Suicidal ideation is defined as a "yes" answer to any 1 of 5 suicidal ideation questions, which included a wish to be dead and 4 different categories of active suicidal ideation. Suicidal behavior is defined as a "yes" answer to any of 5 suicidal behavior questions: preparatory acts or behavior, aborted attempt, interrupted attempt, actual attempt, and completed suicide. Suicidal ideation and behavior are defined as treatment-emergent (TE) if not present at baseline. A summary of serious and other non-serious adverse events regardless of causality is located in the Reported Adverse Event module.

All participants who have non-missing values at baseline and at least one post-baseline value.

Arizona Sexual Experiences (ASEX) Questionnaire is a 5-item rating scale that quantifies sex drive, arousal, vaginal lubrication/penile erection, ability to reach orgasm, and satisfaction from orgasm. Each item is rated from 1 (extremely) to 6 (no/never). Possible total scores ranged from 5 to 30, with the higher scores indicating more sexual dysfunction.

All participants who have non-missing values at baseline and at least one post-baseline value. Last observation carried forward (LOCF) methodology was used.

Massachusetts General Hospital Cognitive and Physical Functioning Questionnaire (CPFQ) is a 7-item participant-rated questionnaire pertaining to a participant's cognitive and physical well-being. It assesses motivation, wakefulness, energy, focus, recall, word-finding difficulty, and mental acuity. Each item is scored on a 6-point scale ranging from 1 (greater than normal) to 6 (totally absent). Total score is reported and ranges from 7 to 42, with higher scores indicating greater impairment.

All participants who have non-missing values at baseline and at least one post-baseline value. Last observation carried forward (LOCF) methodology was used.

Blood pressure measurements were taken 3 times at each visit in a sitting position. The average of the 3 values was used for analysis. Least Squares (LS) means were calculated using a mixed model repeated measures (MMRM) analysis which included terms for the fixed categorical effects of treatment, country, visit, and treatment-by-visit interaction, as well as the continuous, fixed covariates of baseline and baseline-by-visit interaction.

All randomized participants who have non-missing values at the time of randomization and at least one post-randomization value.

Blood pressure measurements were taken 3 times at each visit in a sitting position. The average of the 3 values was used for analysis.

All participants who have non-missing values at baseline and at least one post-baseline value. Last observation carried forward (LOCF) methodology was used.

Pulse rate measurements were collected when the participant was in a sitting position. Least Squares (LS) means were calculated using a mixed model repeated measures (MMRM) analysis which included terms for the fixed categorical effects of treatment, country, visit, and treatment-by-visit interaction, as well as the continuous, fixed covariates of baseline and baseline-by-visit interaction.

All randomized participants who have non-missing values at the time of randomization and at least one post-randomization value.

Pulse measurements were collected when the participant was in a sitting position.

All participants who have non-missing values at baseline and at least one post-baseline value. Last observation carried forward (LOCF) methodology was used.