A Phase 2 interventional study of Mirtazapine and Placebo in Stimulant Use Disorder, sponsored by Washington State University. Recruiting at 1 site in United States. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-07-02.
Sponsored by Washington State University · Phase 2, Interventional, and Treatment
This project will evaluate the ability of Mirtazapine (MZP), a pharmacologically unique medication with a growing body of evidence to support its efficacy and safety for the treatment of methamphetamine (MA) use among medication for opioid use disorder (MOUD) patients, to significantly decrease MA use and related health-impairing behaviors. MZP has already successfully been used in the treatment of methamphetamine (detailed further below and in the Appendices).
The investigators hypothesize that those assigned to the MZP plus treatment as usual (TAU) MZP+TAU arm will demonstrate significantly increased rates of biochemically verified abstinence from MA and other substances of abuse and experience improvements in health impairing behaviors relative to the placebo (PLO)+TAU arm across the 10-week treatment and follow-up periods.
Washington State University is the lead sponsor of 83 studies on the registry; 16 are open to participants now.
Of its 7 completed or terminated interventional studies of FDA-regulated products, 4 (57%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
DSM diagnostic criteria
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Mirtazapine + Treatment as Usual
Drug: Mirtazapine
Placebo + Treatment as Usual
Drug: Placebo
This is a Phase 2, randomized, double-blind, placebo-controlled clinical trial (RCT) to evaluate the ability of mirtazapine (MZP) to increase methamphetamine (MA) abstinence among treatment-seeking medication for opioid use disorder (MOUD) adults.
Placebo to match.
Urinanalysis Verified Increased Days of MA Abstinence
Determine if participants randomized to the MZP+TAU arm use less MA compared to those assigned to the PLO+TAU arm. We hypothesize that those assigned to the MZP+TAU arm will demonstrate significantly increased rates of biochemically verified MA abstinence relative to those in the PLO+TAU arm across the 10-week treatment period and 3-month follow-up periods.
Time frame: Weeks 2 to Week 22
Actigraphy Verified Improved Sleep Patterns
Determine if participants randomized to the MZP+TAU arm demonstrate improvements in sleep compared to those assigned to the PLO+TAU arm. We hypothesize that those assigned to the MZP+TAU arm will demonstrate improvements in objectively verified sleep relative to the PLO+TAU arm across the 10-week treatment and 3-month follow-up periods.
Time frame: Week 2 to Week 22
Self Reported Quantity of Adverse Events
Determine if participants randomized to the MZP+TAU arm experience the same number of adverse events compared to those in the PLO+TAU arm. We hypothesize that those assigned to the MZP+TAU arm will demonstrate statistically equivalent numbers of adverse events relative to those in the PLO+TAU arm across the 10-week treatment and 3-month follow-up periods.
Time frame: Week 2 to Week 22
Urinanalysis Verified Increased Days of Abstinence from Other Substances
Determine if participants randomized to the MZP+TAU arm abstain from other substances of abuse (e.g. illicit opioids, cocaine) and demonstrate improvements in MA-associated health-impairing outcomes (e.g. cravings, sleep quality and HIV risk behavior) compared to those assigned to the PLO+TAU arm.
Time frame: Week 2 to Week 22
Started Jun 2024 (actual). Primary completion is estimated for Dec 2026, 29 months after the start.
How these figures are worked out, and which studies are left out of them.
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Studies of the drug tested here: Mirtazapine
Washington State University