NCT07284667 · ACADIA Pharmaceuticals Inc.
ACP-211 Monotherapy for Major Depressive Disorder With Inadequate Antidepressant Response
(NORLIGHT)
What this study is about
The goal of this clinical trial is to learn if ACP-211 can help treat adults with major depressive disorder (MDD) who have not improved with antidepressant therapy (ADT), including those with treatment resistant depression (TRD).
View original scientific description
The goal of this clinical trial is to learn if ACP-211 can help treat adults with major depressive disorder (MDD) who have not improved with antidepressant therapy (ADT), including those with treatment resistant depression (TRD).
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Adults ≥18 and ≤65 years of age
- Provides written informed consent
- Clinical diagnosis of MDD
- History of inadequate response to at least two antidepressants, with at least one inadequate response documented during the current episode
- Currently treated with an approved antidepressant at a stable dose prior to Screening
- MADRS total score ≥28, CGI-S score ≥4 , and QIDS-SR16 score ≥16 at Screening and Baseline
- Females of childbearing potential must have a negative pregnancy test and agree to use acceptable contraception; males must agree to use barrier protection and refrain from sperm donation
Exclusion criteria
- Current diagnosis of certain personality disorders or persistent depressive disorder
- Recent substance use disorders, excluding caffeine or nicotine
- Active suicidal risk or recent suicidal attempt
- History of schizophrenia, psychotic disorders, bipolar disorder, or MDD with psychotic features
- Current treatment requirement for PTSD, acute stress disorder, panic disorder, or OCD
- History of neuroleptic malignant syndrome, serotonin syndrome, or epilepsy (except single febrile seizure in infancy)
- Documented non-response to ADT, including ketamine or esketamine
- Allergy or sensitivity to ketamine or esketamine
- Significant cardiovascular disease
- Positive history of hepatitis B, hepatitis C, or HIV infection
- Unstable diabetes or uncontrolled medical conditions
- Positive urine drug test for an illicit drug or cannabis
- Received neuromodulation therapies (ECT,TMS, VNS, DBS) in the current depressive episode
- Recent initiation or change in psychotherapy Additional inclusion/exclusion criteria apply. Participants will be evaluated at Screening to ensure that all criteria for study participation are met.
Where
- Birmingham, Alabama
- Chino, California
- La Jolla, California
- Orange, California
- Denver, Colorado
- Hollywood, Florida
- Largo, Florida
- Orlando, Florida
- Tampa, Florida
- West Palm Beach, Florida
- Worcester, Massachusetts
- Saint Charles, Missouri
And 8 more locations — see the full list below.
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 8, 2026 · Source of record for eligibility and locations