The Relationship Among Changes in Brain Network Activation in Adult Outpatients With Major Depressive Disorder

Inclusion Criteria

• The subject has single episode or recurrent MDD (acute onset of recurrence of recurrent MDD with poor inter-episode recovery) (inter-episode periods cannot meet full MDD criteria) as the primary diagnosis according to DSM-IV-TR criteria. The current major depressive episode (MDE) will be confirmed using the Mini International Neuropsychiatric Interview (MINI V6.0.0).
• The subject has a MADRS total score ≥26.
• Subject reports subjective cognitive dysfunction (such as difficulty concentrating, slow thinking, and difficulty in learning new things or remembering things).
• The reported duration of the current MDE is at least 3 months and no longer than 24 months.
• The subject is a man or woman between 18 and 65 years old, inclusive.
• Right-handed, normal (corrected) vision, and normal hearing.

Exclusion Criteria

• The subject has a score of ≥70 on the Digit Symbol Substitution Test (DSST) at the Baseline Visit.
• Failure to respond to or inability to tolerate an adequate trial of vortioxetine in the past.
• Exposure to an investigational compound 30 days prior to enrollment
• Exposure to any psychoactive or otherwise excluded medication within five half-lives of the baseline visit or during the study. Excluded medications include: antidepressants, anxiolytics, anticonvulsants, barbiturates, chloral hydrate, lithium, antipsychotics, benzodiazepines, hypnotics, monoamine oxidase inhibitors (MAOIs), muscle relaxers, triptans, centrally-acting antihistamines, central alpha-2 agonists, decongestants, psychostimulants, dopamine agonists, opioid pain medications, oral corticosteroids, L-methylfolate, S-adenosyl methionine (SAMe), 5-HTP (hydroxytryptophan), St. John's Wort,
• The subject has 1 or more of the following:
• Primary psychiatric disorder other than MDD as defined in the Diagnostic and Statistical Manual of Mental Disorders 4 Text Revision (DSM-IV-TR) (as assessed by the MINI, Version 6.0.0).
• Current or history of attention deficit hyperactivity disorder (ADHD), pervasive developmental disorder, manic or hypomanic episode, schizophrenia, or any other psychotic disorder, including major depression with psychotic features, mental retardation, organic mental disorders, or mental disorders due to a general medical condition as defined in the DSM-IV-TR.
• Current diagnosis of alcohol or other substance abuse or dependence (excluding nicotine or caffeine) as defined in the DSM-IV-TR that has not been in sustained full remission for at least 6 months (for abuse) and 12 months (for dependence) prior to Screening.
• Positive urine drug screen prior to Baseline.
• Presence or history of a clinically significant neurological disorder (including epilepsy).
• Neurodegenerative disorder (Alzheimer Disease, Parkinson Disease, multiple sclerosis, Huntington Disease, etc).
• Any unstable medical condition as determined by the principal investigator (PI).
• Any DSM-IV Axis II disorder that might compromise the study as determined by the PI.
• The subject has any other disorder for which the treatment takes priority over treatment of MDD or is likely to interfere with study treatment or impair treatment compliance.
• The subject has physical, cognitive, or language impairment of such severity as to adversely affect the validity of the data derived from the neuropsychological tests.
• The subject has a significant risk of suicide according to the PI's clinical judgment.
• The subject, in the opinion of the PI, poses a risk of harm to others.
• The subject has initiated formal cognitive or behavioral therapy, systemic psychotherapy within less than 6 months of study screening, or has plans to initiate such therapy during the study.
• The subject has received electroconvulsive therapy, vagus nerve stimulation, or repetitive transcranial magnetic stimulation within 12 months prior to Screening.
• The current MDE is considered by the PI to have been resistant to 2 adequate antidepressant treatments of at least 6 weeks