Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Multi Center, Randomized, Double-blind, Placebo Controlled, Parallel-group Study to Investigate the Efficacy and Safety of RO4995819 Versus Placebo, as Adjunctive Therapy in Patients With Major Depressive Disorder Having Inadequate Response to Ongoing Antidepressant Treatment (ARTDeCo)
Brief Summary: This multi-center, randomized, double-blind, placebo-controlled, parallel-group study will investigate the efficacy and safety of RO4995819 as adjunctive therapy in patients with major depressive disorder having inadequate response to ongoing antidepressant treatment. Patients will be randomized to receive once daily doses of 5 mg, 15 or 30 mg of RO4995819 or matching placebo. The anticipated time on study treatment is 6 weeks.


Options:
A: Inclusion Criteria:

* At the time of signing the informed consent form (ICF), participant must be a man or woman 18 (or older if the minimum legal age of consent in the country in which the study is taking place is greater than \[\>\]18) to 64 years of age, inclusive
* At the start of the screening/prospective observational phase, participant must meet the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) diagnostic criteria for single-episode major depressive disorder (MDD) (if single-episode MDD, the duration must be greater than or equal to \[\>=\] 2 years) or recurrent MDD, without psychotic features, based upon clinical assessment and confirmed by the Mini-International Neuropsychiatric Interview (MINI)
* At the start of the screening/prospective observational phase, participant must have an Inventory of Depressive Symptomatology-Clinician rated ( IDS-C30) total score of greater than or equal to (\>=) 34
* At the start of the screening/prospective observational phase, participant must have had non-response (greater than or equal to \[\<=25\] percent \[%\] improvement) to ≥1 but less than or equal to (\<=) 5 (if current episode is \>2 years, upper limit is applicable to only the last 2 years) oral antidepressant treatments in the current episode of depression, assessed using the Massachusetts General Hospital - Antidepressant Treatment Response Questionnaire (MGH-ATRQ) and documented by medical history and pharmacy/prescription records, for the current episode of depression. In addition, the participant is taking a different oral antidepressant treatment (on the MGH-ATRQ) for at least the previous 2 weeks at or above the minimum therapeutic dose
* The participant's current major depressive episode, depression symptom severity (Week 1 MADRS total score \>=28 required), and antidepressant treatment response in the current depressive episode, must be confirmed using a Site Independent Qualification Assessment

Exclusion Criteria:

* Participants who have previously demonstrated nonresponse of depressive symptoms to esketamine or ketamine in the current major depressive episode, to all 4 of the oral antidepressant treatment options available for the double-blind induction phase (ie, duloxetine, escitalopram, sertraline, and venlafaxine extended release \[XR\]) in the current major depressive episode (based on MGH-ATRQ), or an adequate course of treatment with electroconvulsive therapy (ECT) in the current major depressive episode, defined as at least 7 treatments with unilateral/bilateral ECT
* Participant has received vagal nerve stimulation (VNS) or has received deep brain stimulation (DBS) in the current episode of depression
* Participant has a current or prior DSM-5 diagnosis of a psychotic disorder or MDD with psychosis, bipolar or related disorders (confirmed by the MINI), comorbid obsessive compulsive disorder, intellectual disability (DSM-5 diagnostic codes 317, 318.0, 318.1, 318.2, 315.8, and 319), borderline personality disorder, antisocial personality disorder, histrionic personality disorder, or narcissistic personality disorder
* Participant has homicidal ideation/intent, per the investigator's clinical judgment, or has suicidal ideation with some intent to act within 6 months prior to the start of the screening/prospective observational phase, per the investigator's clinical judgment or based on the Columbia Suicide Severity Rating Scale (C-SSRS)
* Participants with history of moderate or severe substance or alcohol use disorder according to DSM-5 criteria
B: Inclusion Criteria:

* Signed informed consent before any study-related procedures start.
* The patient is previously diagnosed with Major Depressive Disorder (MDD) and currently taking an antidepressant for at least 6 weeks.
* Patient has a history of poor response to 1 or more antidepressants (in addition to the antidepressant the patient is taking at enrollment) after exposure at adequate doses or maximum tolerated doses for ≥4 weeks.

Exclusion Criteria:

* Patient has a lifetime history of schizophrenia, bipolar, psychosis or psychotic depression.
* Patient has a lifetime history of failure to ECT therapy.
* Patient is pregnant or breast feeding.
* Length of current episode of depression exceeds ≥2 years.
C: * INCLUSION CRITERIA:

General patient inclusion criteria

1. Male or female subjects, 18 to 65 years of age.
2. Each subject must have a level of understanding sufficient to agree to all required tests and examinations and sign an informed consent document.
3. Subjects must fulfill DSM-IV criteria for Major Depressive Disorder (MDD) without psychotic features, based on clinical assessment and confirmed by a structured diagnostic interview, SCID-P.
4. Subjects must have an initial score of at least 20 on the MADRS at screen and at baseline of study phase I.
5. Subjects must have failed to respond in the past to an adequate dose and duration of at least one antidepressant (SSRI, bupropion, or venlafaxine) during a depressive episode
6. Current depressive episode of at least 4 weeks duration.

Additional inclusion criteria for substudy 4 (patients with MDD)

1. Age of onset less than 40 years of age.
2. Subjects with MDD must fulfill DSM-IV criteria for Major Depression single episode or recurrent without psychotic features based on clinical assessment and confirmed by a structured diagnostic interview (SCID-P).
3. A failed adequate trial of ECT would count as an adequate antidepressant trial.
4. In women of childbearing age, a negative pregnancy test within 24 hours of MRI.

Inclusion criteria for healthy control subjects (Substudy 4 only)

1. Age 18-65 years.
2. Written informed consent completed.

EXCLUSION CRITERIA:

General patient exclusion criteria

1. Current or past diagnosis of Schizophrenia or any other psychotic disorder as defined in the DSM-IV.
2. Subjects with a history of DSM-IV drug or alcohol dependency or abuse (except for nicotine or caffeine) within the preceding 3 months.
3. Female subjects who are either pregnant or nursing.
4. Serious, unstable illnesses including hepatic, renal, gastroenterologic, respiratory, cardiovascular (including ischemic heart disease), endocrinologic, neurologic, immunologic, or hematologic disease.
5. Subjects with uncorrected hypothyroidism or hyperthyroidism.
6. Subjects with one or more seizures without a clear and resolved etiology.
7. Treatment with a reversible MAOI within 4 weeks prior to study phase I.
8. Treatment with fluoxetine within 5 weeks prior to study phase I.
9. Treatment with any other concomitant medication not allowed (Appendix A for Substudy 2; Appendix G for Substudy 4) 14 days prior to study phase I.
10. No structured psychotherapy will be permitted during the study.
11. Current NIMH employee/staff or their immediate family member.

Additional Exclusion Criteria for substudy 2 (patients with MDD)

1. Previous treatment with ketamine or hypersensitivity to amantadine.

Additional Exclusion Criteria for Substudy 4 (patients with MDD)

1. Subjects who currently are using drugs (except for caffeine or nicotine), must not have used illicit substances in the 2 weeks prior to screen and must have a negative alcohol and drug urine test (except for prescribed benzodiazepines) urine test at screening.
2. Presence of any medical illness likely to alter brain morphology and/or physiology (e.g., hypertension, diabetes) even if controlled by medications.
3. Clinically significant abnormal laboratory tests.
4. For imaging procedures, Presence of metallic (ferromagnetic) implants (e.g, heart pacemaker, aneurysm clip).
5. Subjects who, in the investigator's judgment, pose a current serious suicidal or homicidal risk, or who have a MADRS item 10 score of \>4.

Exclusion Criteria for healthy control subjects (Substudy 4 only)

1. Current or past Axis I diagnosis
2. Presence of metallic (ferromagnetic) implants (e.g., heart pacemaker, aneurysm clips).
3. Presence of medical illness likely to alter brain morphology and/or physiology (e.g., hypertension, diabetes) even if controlled by medications.
4. Treatment with any of the exclusionary medications detailed in Appendix G 14 days prior to Phase 1 of the Substudy 4.
5. Current or past alcohol or substance abuse or dependence diagnosis (except for nicotine or caffeine).
6. Presence of psychiatric disorders in first-degree relatives.
7. Female subjects who are either pregnant or nursing.

7.8.Current NIMH employee/staff or their immediate family member.
D: Inclusion Criteria:

* Adult patients, 18-65 years of age
* Major depression disorder without psychotic features
* Inadequate response to current, ongoing antidepressant treatment as defined by protocol
* Having at least one but no more than 2 antidepressant treatment trial failures
* Body mass index (BMI) 18.0-35.0 kg/m2 inclusive

Exclusion Criteria:

* Patient currently receives treatment with a combination of 3 or more antidepressants
* Significant ongoing use of high doses of barbiturates, benzodiazepines or other anxiolytic drugs
* Patient previously received RO4995819
* Patient participated in an investigational drug or device trial within 6 months of screening
* History of non-response to, or current use of non-pharmacological treatment including Electroconvulsive Therapy (ECT), Vagus Nerve Stimulation (VNS), or Repetitive Transcranial Magnetic Stimulation (RTMS)
* Past or present psychotic symptoms

Answer: D