Medication-Induced Psychosis: Recognizing Symptoms and What to Do in an Emergency

It’s not rare for someone to suddenly become paranoid, hear voices, or believe things that aren’t true-especially after starting a new medication. These aren’t just "bad side effects." They’re signs of medication-induced psychosis, a real and dangerous reaction that can happen with common drugs you might never suspect. Unlike schizophrenia or bipolar disorder, this isn’t a lifelong condition-it’s a medical emergency triggered by a drug, and it can flip a person’s reality in hours. The good news? If caught early, it usually goes away completely. The bad news? Many doctors miss it.

What Does Medication-Induced Psychosis Actually Look Like?

People experiencing this aren’t "going crazy." Their brain is reacting to a chemical change caused by a drug. The symptoms are unmistakable:

• Delusions-strong false beliefs, like thinking someone is spying on them or poisoning their food
• Hallucinations-seeing people who aren’t there, hearing voices whispering or yelling, feeling bugs crawling under the skin
• Disorganized speech-jumping between topics, saying things that don’t connect, using made-up words
• Severe confusion-forgetting where they are, not recognizing family members
• Extreme agitation or aggression-sudden outbursts, pacing, threatening behavior
• Mood swings-rapid shifts from panic to flat emotion

These aren’t vague feelings. They’re intense, persistent, and often terrifying-for the person experiencing them and everyone around them. Auditory hallucinations and paranoid delusions are the most common, especially with stimulants like cocaine or amphetamines. In fact, nearly 100% of heavy cocaine users who develop psychosis report hearing voices telling them they’re in danger.

Which Medications Can Cause This?

It’s not just illegal drugs. Many prescription and even over-the-counter medicines carry this risk. Here are the most common culprits:

• Corticosteroids (like prednisone)-used for asthma, arthritis, or autoimmune diseases. Up to 5.7% of people on high doses develop psychosis. Mood changes often come first-irritability, anxiety-before full hallucinations.
• Antimalarials (especially mefloquine)-used by travelers. The European Medicines Agency has logged over 1,200 psychosis cases since the 1980s. Nightmares and paranoia can start days after taking the first pill.
• Antiretrovirals (like efavirenz)-for HIV. About 2.3% of users report severe psychiatric side effects, including psychosis. The FDA requires warning labels.
• Antidepressants (SSRIs, SNRIs)-rare, but documented. Especially when starting or increasing the dose. Some people report sudden paranoia or delusions within days.
• Stimulants (methylphenidate, amphetamines)-used for ADHD. Psychosis occurs in over 11% of methamphetamine users and nearly 15% of amphetamine users.
• First-gen antihistamines (like diphenhydramine)-found in sleep aids and allergy pills. High doses can cause delirium and hallucinations, especially in older adults.
• Levodopa-for Parkinson’s. Can trigger hallucinations even at standard doses.
• Opioids and high-dose NSAIDs-less common, but possible, especially with long-term use or kidney problems.

And yes-even marijuana can do it. About 10% of regular cannabis users report psychotic symptoms, especially with high-THC strains. The key difference? If the hallucinations stop when the drug leaves the body, it’s likely medication-induced. If they stick around, it’s something else.

Who’s Most at Risk?

Not everyone who takes these drugs will develop psychosis. But certain people are far more vulnerable:

• People with a personal or family history of schizophrenia, bipolar disorder, or other psychotic illnesses
• Those with a history of substance use disorder-74% of first-time psychosis patients have had a past SUD
• Women-studies show higher rates of medication-induced psychosis in females, especially with steroids and antimalarials
• Older adults-slower metabolism means drugs stick around longer, increasing risk
• People with kidney or liver disease-can’t clear drugs properly

It’s also more likely if someone is taking multiple drugs at once. A person on prednisone for arthritis who also takes diphenhydramine for sleep? That combo can push someone over the edge.

Emergency Management: What to Do Right Now

If someone suddenly becomes psychotic after starting a new medication, don’t wait. Don’t assume it’s "just stress." Call emergency services or go to the nearest ER immediately.

Here’s what happens in the emergency room:

1. Stop the drug-The first and most important step. If it’s a prescription, the doctor will discontinue it. If it’s an OTC pill, they’ll confirm what was taken and how much.
2. Stabilize the patient-If they’re agitated or violent, they may be given a short-acting antipsychotic like olanzapine or quetiapine. Benzodiazepines (like lorazepam) are also used to calm extreme anxiety or seizures.
3. Rule out other causes-Doctors will check for infections, low blood sugar, electrolyte imbalances, or alcohol withdrawal-all can mimic psychosis.
4. Monitor closely-They’ll watch for heart issues, high body temperature (especially with stimulants), or muscle breakdown (rhabdomyolysis).

For alcohol or benzo withdrawal psychosis, treatment is different. They’ll give a controlled taper of benzodiazepines to prevent delirium tremens-a life-threatening condition.

And yes-sometimes hospitalization is necessary. If someone is a danger to themselves or others, involuntary holds under mental health laws are legal and often lifesaving.

How Long Does It Last?

Recovery time depends on the drug:

• Cocaine or amphetamines-Symptoms often clear in 24 to 72 hours after last use
• Steroids-Take 4 to 6 weeks to fully resolve after stopping
• Antimalarials like mefloquine-Can take weeks, sometimes months, for brain chemistry to reset
• Antidepressants-Usually improve within 1 to 2 weeks of discontinuation

Most people recover fully. But here’s the catch: up to 10% of first-episode psychosis cases in ERs are medication-induced. That means nearly 1 in 10 people admitted for "new psychosis" actually had a drug trigger. If symptoms linger beyond a month after stopping the drug, doctors must consider an underlying psychotic disorder like schizophrenia.

Why This Gets Missed So Often

Primary care doctors miss it all the time. A 2019 study found only 38% felt confident diagnosing it. Why?

• They assume psychosis = schizophrenia
• They don’t ask about recent medication changes
• Patients don’t volunteer that they took an OTC sleep aid or started a new steroid
• Doctors don’t know which drugs carry this risk

It’s not their fault. The information isn’t always clear in drug labels. But it’s critical to ask: "When did this start? What new meds or supplements did you begin taking?"

How to Prevent It

Prevention is simple, but often ignored:

• Always tell your doctor about all medications, including OTC pills, supplements, and herbal products
• If you’re prescribed a drug known to cause psychosis (like steroids or mefloquine), ask: "What mental side effects should I watch for?"
• Don’t start new drugs without knowing the risks-read the FDA patient guide if one exists
• Monitor for early warning signs: anxiety, sleeplessness, irritability, racing thoughts-these often come before full psychosis
• If you have a psychiatric history, tell your doctor before starting any new medication

And if you’re caring for someone on high-risk meds-keep a close eye. A sudden change in behavior isn’t "just them." It could be the drug.

What Happens After the Emergency?

Once the acute phase passes, follow-up is non-negotiable. You need psychiatric care for at least 3 months. Why?

• To confirm the psychosis was truly drug-induced
• To watch for delayed onset of schizophrenia or bipolar disorder
• To address any substance use issues that may have contributed
• To help the person rebuild trust in their own mind

Some people need therapy to process the trauma of experiencing psychosis. Others need help quitting drugs or adjusting to life after stopping a medication they thought was helping them.

The bottom line: medication-induced psychosis is treatable, reversible, and often preventable. But it demands urgency. Ignoring it can lead to hospitalization, lost jobs, broken relationships, or worse. If you or someone you know starts acting strangely after a new drug-act fast. It’s not paranoia. It’s a medical alert.