The Malaria Pill That Broke Veterans

For much of the 1990s and early 2000s, the U.S. military issued mefloquine (Lariam) as a standard prophylactic against malaria for deployed service members. It was cheap, required only weekly dosing, and seemed convenient for large-scale use. But the true cost became clear later. Instead of simply preventing disease, mefloquine left thousands of veterans with lasting psychiatric and neurological injuries.

Problems that were often dismissed, misdiagnosed, or ignored by the very institutions tasked with their care.

Mounting Warnings

By the late 1990s, reports were already surfacing that mefloquine carried serious neuropsychiatric risks. Clinical case series documented hallucinations, paranoia, anxiety, and depression linked to the drug (Nevin & Croft, 2016). The FDA ultimately issued a black-box warning in 2013, explicitly stating that mefloquine can cause “neuropsychiatric adverse reactions that may persist or become permanent” (FDA Drug Safety Communication, 2013).

A 2020 National Academies of Sciences report concluded that there is sufficient evidence linking mefloquine to long-term vestibular damage, depression, and psychosis in some users (National Academies, 2020). These findings directly undermined the earlier assumption that any side effects were “short-lived” or resolved after discontinuation.

Lasting Impact on Veterans

One of the most troubling features of mefloquine is that its effects often did not resolve once service members stopped taking it. A case report published in Military Medical Research described a veteran with persistent paranoia, anxiety, and sleep disturbance years after exposure, initially misdiagnosed as PTSD (Springer, 2016).

A 2019 VA study noted that chronic psychiatric illness among some veterans may actually represent undiagnosed mefloquine toxicity, not PTSD or TBI, and warned that misdiagnosis leaves veterans without proper care (PMC, 2019). This diagnostic confusion has cost veterans years of benefits, treatment, and recognition.

Laboratory research has confirmed the biological plausibility of these outcomes. Studies show that mefloquine causes direct neurotoxicity at the cellular level, disrupting calcium homeostasis in neurons and damaging brain function (MDPI, 2024). These mechanisms align with the psychiatric and vestibular symptoms documented clinically.

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Psychiatric Risks and Forensic Scrutiny

Because of its psychiatric effects, mefloquine has even been examined in forensic psychiatry. The Journal of the American Academy of Psychiatry and the Law reported cases where paranoia, aggression, and suicidal ideation were traced back to mefloquine use, raising concerns about accountability and legal responsibility (J Am Acad Psychiatry Law, 2013).

Other militaries responded earlier than the U.S. in curtailing its use. The Canadian Forces, for example, significantly restricted mefloquine prescriptions after widespread veteran complaints and an official review (ScienceDirect, 2021). The Australian Defence Force later acknowledged improper screening and surveillance of mefloquine trials on its soldiers (ScienceDirect, 2021).

Institutional Silence

Despite the evidence, recognition in the U.S. has been slow. Even today, many veterans who present with psychiatric or vestibular symptoms after deployments to Africa, Afghanistan, or Iraq struggle to get providers to even ask whether mefloquine was prescribed. The drug has faded from standard military use, but its legacy remains etched into the lives of those who took it.

One veteran only secured VA service connection for mefloquine-related disability after years of appeals, demonstrating how rare acknowledgment remains (PMC Case Study, 2019).

Why This Matters

Veterans who were ordered to take mefloquine deserve recognition, screening, and treatment tailored to their unique injuries. Too many were told their symptoms were “all in their head” or misclassified under blanket PTSD labels. That not only fails them medically, but also deepens the stigma of the so-called “broken veteran.”

At Combat Veterans of America (CVA), we believe part of fixing that stigma is telling the truth about what actually broke some of us. For years, society has been told a single story — that every veteran who struggles is broken by combat. The reality is far more complicated. Sometimes it wasn’t the firefight or the roadside bomb. Sometimes it wasn’t the deployment itself. Sometimes it was the pill we were given before combat even began.

Mefloquine was handed out like it was harmless, a simple weekly dose to keep malaria away. We called it Malaria Monday. What wasn’t explained were the side effects that could last a lifetime with hallucinations, paranoia, depression, balance disorders, nightmares that never stopped. Many veterans came home with wounds nobody could see, and when they spoke up, they were told it was just PTSD, or worse, that it was all in their head. That dismissal has done as much damage as the drug itself.

By speaking openly about mefloquine and similar issues, CVA is pushing back against the “broken veteran” label. Veterans aren’t broken. They were too often, failed. Failed by systems that cut corners, ignored warnings, and refused to listen when soldiers came back with symptoms they couldn’t explain. Fixing that means starting with honesty. Naming the cause. Owning the mistakes. And making sure the next generation of service members doesn’t carry the same burden.

If you or someone you know took mefloquine during deployment and still struggle with unexplained psychiatric or neurological symptoms, take three steps today:

1. Document your exposure — note where and when you were prescribed the drug.

2. Request a full neurological and psychiatric evaluation, and ask your provider to review mefloquine literature.

3. Connect with advocacy organizations and peers who understand the issue.

   
   

Recognition starts with truth. Veterans harmed by mefloquine deserve nothing less.