Inclusion Criteria:

• have provided voluntary written informed consent for trial participation after the scope and nature of the investigation were explained to them, and before starting any trial-related activities (before Screening);
• be able to speak, read, understand, respond to questions, and follow instructions in English or their native language;
• have DSM-IV severe depressive episode with psychotic features, as diagnosed by the MINI for single or recurrent episodes (296.24 or 296.34); have a score on PANSS item "Delusions" AND/OR "Hallucinatory behavior" of at least 4 at Screening and Baseline;
• have a PANSS Positive Scale score of at least 16 at Screening and Baseline;
• have a total score of at least 18 on the HAMD 17-item scale at Screening and Baseline;
• be on a stable dose of "usual treatment", which had to consist of an antidepressant, an antipsychotic, a mood stabilizer or any combination of these 3 drug classes;
• be between 18 and 75 years of age (inclusive) at Screening;
• be willing to be hospitalized for at least 11 days from Screening onwards.

Exclusion Criteria:

• have any other current psychiatric diagnosis (according to the MINI) except MDD, such as organic mental syndromes and disorders, delirium or anxiety disorders;
• have a lifetime psychiatric diagnosis of psychotic disorders (according to the MINI), or a MINI diagnosis of past manic episode;
• be at significant risk of committing suicide, as indicated by a score greater than 9 on the revised InterSePT Scale for Suicidal Thinking (ISST);
• be currently treated with carbamazepine or valproate;
• be currently treated with midazolam;
• be treated with electroconvulsive therapy in the current episode;
• be currently treated with more than one antidepressant;
• be currently treated with more than one antipsychotic;
• be currently treated with more than one mood stabilizer;
• have a "usual treatment" started or discontinued in the 2 weeks before Randomization;
• have a "usual treatment" dose change within the week prior to Randomization;
• have any clinically unstable or uncontrollable renal, hepatic, respiratory, hematological, cardiovascular or cerebrovascular disease that would put the patient at risk of safety or bias assessment of efficacy; have known hypersensitivity reactions to glucocorticoid antagonists;
• have any clinically significant abnormal laboratory data (e.g. aspartate amino transferase (ASAT) and/or alanine amino transferase (ALAT) values > 2x normal range upper limit) or ECG results, or a clinically significant abnormal outcome at the physical examination at the screening visit;
• have any untreated or uncompensated clinically significant endocrine disorder;
• have a MINI diagnosis of alcohol and/or drug dependence;
• have a confirmed positive result on the drug screening test for any illicit drug, except cannabis, at Screening;
• be using hormone replacement therapy at Screening;
• have required concomitant treatment with corticosteroids, like dexamethasone, prednisone or cortisol (topical use is allowed);
• be diagnosed with Cushing's disease;
• be women of childbearing potential without adequate contraception;
• be women with a positive pregnancy test at Screening or Baseline, or breastfeeding mothers;
• be males with a current diagnosis of prostate hypertrophia or past history (less than 3 months) of symptoms of prostate hypertrophia.
• be currently treated with clozapine (per Amendment III);
• be currently treated with systemic or topical ketaconazole.