A 60-cent antidepressant just produced the first credible pharmacotherapy signal for methamphetamine use disorder

For two decades, the gap between methamphetamine and the rest of the addiction-medicine field has been embarrassing. There is no FDA-approved medication for methamphetamine use disorder — none for amphetamines, none for cocaine, none for any stimulant. Buprenorphine for opioids. Naltrexone, acamprosate, disulfiram for alcohol. For stimulants, prescribers improvise, and the people they treat carry the cost of that improvisation. So when a generic antidepressant shows up in a randomized trial published in JAMA Psychiatry and modestly but meaningfully reduces use, the right reaction is not “a small effect.” The right reaction is “we finally have a real pharmacotherapy signal to build on.”

What the trial actually found

The drug is mirtazapine. It has been around since the 1990s, prescribed widely for depression and insomnia, generic, costing under a dollar a day. In the new trial, people with methamphetamine use disorder who took mirtazapine reduced their use by an average of 2.2 days per 28-day period compared with placebo. That is not a cure. It is also not nothing. In a category where every prior pharmacotherapy candidate has either failed cleanly or required complex combinations, a single, take-home, widely available drug producing a measurable reduction is genuine progress.

Two practical features matter as much as the effect size. First, mirtazapine is dosed at home — no daily clinic visits, no observed-dosing requirements, no DEA scheduling overhead. Second, it is already in the formulary every prescriber knows. That changes the implementation question. The question is no longer “how do we get a new drug approved and stocked.” It is “do we want to start using a drug we already have.”

Why this fits a longer arc the FDA itself has been pushing

This trial does not arrive in a vacuum. In November 2023, the FDA issued formal guidance for industry on developing therapies for stimulant use disorders, signaling regulatory openness to medication-based treatment and explicitly inviting endpoints beyond abstinence — reduced use, fewer use-days, reduced craving. Earlier NIH-funded work combining bupropion and naltrexone had shown promise but never crossed into routine practice, in part because of the complexity of two drugs and one of them being injectable. Mirtazapine has neither problem. It is the drug a primary-care provider in Yuma can write for a 32-year-old with stimulant use disorder on Monday afternoon.

Where this still falls short

We are not pretending this is the answer. The effect size is modest. The study population was clinical-trial selected, not the polysubstance-using population that now defines most stimulant overdose mortality — recall that in the most recent surveillance, roughly 70% of stimulant overdose deaths involve fentanyl. A medication that reduces meth-using days by two per month does not, by itself, address the fentanyl-laced supply that is the proximate cause of death. Behavioral interventions — particularly contingency management, which we covered last week — remain the single most evidence-supported intervention for methamphetamine, and CM has stronger effect sizes than this drug. The serious version of “we have a stimulant pharmacotherapy” is “we have a stack — pharmacotherapy plus CM plus harm reduction plus safer-supply work.” Mirtazapine is one square in that stack, not the whole grid.

It also does not erase the access gap. Most outpatient programs do not have a prescriber co-located with their counselors. Many people who use stimulants are not in any treatment program at all. The drug being cheap and take-home is a structural advantage exactly because it can be prescribed in primary care, in jail-release clinics, in mobile units. Whether it actually gets prescribed in those settings is a separate, and harder, question.

What changes today, in practice

For prescribers: this is a real off-label option to discuss with a patient who has methamphetamine use disorder, particularly one with comorbid depression or insomnia, where mirtazapine has long-standing evidence. For families: it is reasonable, today, to ask a treating clinician whether mirtazapine is an option for a loved one. For payers and state Medicaid programs (looking at you, AHCCCS): there is no reimbursement obstacle. The drug is on every formulary. The only thing in the way of using it more is the inertia of “no FDA-approved meds for meth,” and that frame is now incomplete.

For payers and state Medicaid programs (looking at you, AHCCCS): there is no reimbursement obstacle.

Why this matters for people in recovery

For more than a decade, the message a person with stimulant use disorder heard from medicine was, in effect, “there is no pill for this — go to a meeting, get a counselor, hope it sticks.” That message produced predictable outcomes: people staying out of treatment because there was nothing to take, providers feeling helpless because there was nothing to offer, and an overdose surveillance picture in which stimulant-involved deaths now rival opioid-involved deaths. A pharmacotherapy signal — even a modest one — changes that conversation. It does not replace counseling, contingency management, or peer support. It adds to them. If you or someone you love is navigating methamphetamine use, you can ask about this. That is new.

If you want help thinking through what a comprehensive stimulant treatment plan looks like — pharmacotherapy options, contingency management, harm reduction supplies, peer recovery — start with the Rize stimulants resource hub, or use Rize’s free guided assessment to find programs near you that combine medication options with behavioral treatment.