A Cheap Antidepressant May Be the Meth Treatment That's Been Under Our Noses

There are no FDA-approved medications for methamphetamine use disorder. There never have been. While opioid use disorder has buprenorphine, methadone, and naltrexone—three distinct approved medications with robust evidence bases—stimulant use disorder has been left with behavioral therapy alone. Contingency management, the evidence-based intervention that uses financial incentives to reward abstinence, has faced a $75 per incentive federal cap that guts its effectiveness. The medication bench for treating meth is empty.

A study published this week in Alcoholism & Drug Abuse Weekly, a peer-reviewed publication from Wiley, found that mirtazapine—a generic antidepressant that costs roughly $15 per month—was effective in reducing methamphetamine use and was safe for people with methamphetamine use disorder. Researchers described the finding as “safe and cheap,” which in a field accustomed to pharmacological dead ends is notable framing.

Mirtazapine works differently than typical antidepressants. It acts as a noradrenergic and specific serotonergic antidepressant (NaSSA), blocking specific receptors to increase norepinephrine and serotonin availability, while also acting on histamine receptors in a way that produces sedation and appetite stimulation. The latter effects have long been used clinically to treat the weight loss and sleep disruption that accompany methamphetamine withdrawal. The new finding suggests the drug may also reduce ongoing use, not just manage withdrawal symptoms.

This is not the first indication that mirtazapine has potential here—a small 2011 randomized controlled trial published in Drug and Alcohol Dependence found that mirtazapine-treated men who have sex with men significantly reduced methamphetamine use compared to placebo. The new study extends and strengthens that signal.

What the study does not provide is a clear mechanism for why mirtazapine helps. Methamphetamine releases massive amounts of dopamine and norepinephrine in the brain, producing its rewarding effects and, over time, depleting the systems that produce them naturally. Mirtazapine’s noradrenergic action may help stabilize a depleted system. The pharmacology is plausible, though unconfirmed.

The clinical implication is significant regardless of the mechanism. Mirtazapine is off-patent, generic, and prescribed by primary care physicians for depression and anxiety every day. It doesn’t require a special waiver to prescribe (unlike buprenorphine, which required a DEA X-waiver until 2023). It doesn’t require daily clinic visits (unlike methadone for opioid use disorder). A primary care physician in a rural Arizona town who has a patient with methamphetamine use disorder and no access to specialized addiction treatment currently has nothing pharmacological to offer. Mirtazapine might change that—if the evidence holds up in larger trials.

The study’s limitations are worth noting. Alcoholism & Drug Abuse Weekly publishes clinical reports and brief findings; the full methodology and sample size have not been reviewed here. Larger randomized controlled trials will be needed before mirtazapine can be considered for FDA review as a stimulant use disorder treatment. The path from a promising finding to an approved medication is long and expensive, and previous candidates for stimulant use disorder pharmacotherapy—bupropion, modafinil, topiramate, D-amphetamine—have all shown some signal in trials without producing a clear FDA approval.

But the bar is lower than it sounds. In a field with no approved treatments, a cheap, safe, widely available drug with a credible mechanism and a growing evidence base is not a minor finding. It’s a signal the addiction medicine community should be taking seriously—and a reminder that sometimes the compound that ends up mattering most is the one that’s been sitting on the pharmacy shelf for twenty years.

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Rize tracks stimulant use disorder treatment research as part of its two-dimensional coverage model. Arizona has some of the highest methamphetamine use rates in the country — find treatment that addresses stimulant use disorder here.