We’ve all heard that mental illness is caused by chemical imbalances, genetics, or trauma. And sure, those factors play a role. But what if we’ve been missing something huge?
What if some cases of anxiety, depression, panic attacks, OCD, or even psychosis aren’t just “mental health disorders” but actually signs of an infection?
This isn’t just a wild theory—it’s something researchers are starting to take very seriously. And one infection, in particular, keeps showing up in patients with severe psychiatric symptoms: Bartonella.
If you’ve never heard of Bartonella, you’re not alone. It’s most famous for causing cat scratch disease (that thing kids get when they roughhouse with a kitten). But here’s the kicker—this sneaky bacteria isn’t just a mild infection.
It can burrow deep into blood vessels, nerves, and even the brain, triggering all sorts of bizarre and psychiatric symptoms that look just like classic mental illness.
What is Bartonella? And How Do You Get It?
Most people pick up Bartonella from:
🐱 Cats and Fleas – Cat scratches, flea bites, and even being licked by an infected cat.
🐜 Ticks and Lice – Bartonella has been found in ticks, but whether they can pass it to humans is still debated.
🦟 Other Biting Insects – Sandflies and mosquitoes may also be carriers.
Once inside the body, Bartonella doesn’t just hang out in the bloodstream—it finds hiding spots in blood vessel walls, nerves, and the brain, making it incredibly hard to detect and treat.
And here’s where things get really interesting: People with chronic Bartonella infections often develop severe neuropsychiatric symptoms that look exactly like traditional mental illnesses.
The Bartonella-Mental Health Connection: What the Research Says
💡 Psychosis & Bartonella
A 2024 study found that 43% of adults diagnosed with psychosis had Bartonella DNA in their bloodstream—compared to only 14% in the healthy control group. That’s a huge difference.
📖 Frontiers in Psychiatry, 2024
💡 Depression, Anxiety & Sleep Disorders
A study on patients with treatment-resistant depression, anxiety, and chronic sleep issues found that 88% tested positive for Bartonella. Many also had mysterious skin lesions, another telltale sign of the infection.
📖 NC State University, 2020
💡 Schizophrenia & Bartonella
A pilot study detected Bartonella DNA in the blood of 12 out of 17 people diagnosed with schizophrenia or schizoaffective disorder—while only one out of 13 healthy controls tested positive.
📖 UNC Healthcare, 2021
💡 Case Studies of Psychiatric Symptoms Improving with Antibiotics
Patients with agitation, panic attacks, and depression who weren’t responding to standard psychiatric medications showed major improvement when treated with antibiotics targeting Bartonella.
📖 PMC Case Study, 2007
Why This Matters: The Mental Health-Infection Blind Spot
The idea that an infection could cause psychiatric symptoms is not new.
🦠 Strep infections can trigger OCD in kids (PANDAS syndrome).
🦠 Syphilis (another spirochete like Lyme) can lead to psychosis and mania if untreated.
🦠 Chronic viruses like Epstein-Barr have been linked to bipolar disorder and depression.
Yet, for some reason, doctors rarely check for infections when people show up with psychiatric symptoms.
Instead, patients get prescribed medications for life without anyone asking:
❓ Why is this happening?
❓ Could something deeper be triggering these symptoms?
If infections like Bartonella can cause or worsen mental illness, we need to start testing for them—and treating them.
How Do You Know If You Might Have Bartonella?
Since Bartonella is hard to detect, it’s often diagnosed clinically (based on symptoms), not just blood tests.
Common signs of Bartonella:
✔ Sudden-onset anxiety, panic, or depression
✔ Severe sleep disturbances (nightmares, insomnia)
✔ Brain fog, memory issues, or difficulty concentrating
✔ Irritability, rage, or mood swings
✔ Skin lesions or strange stretch mark-like rashes
✔ Neurological symptoms like numbness, tingling, or dizziness
If you have a combination of psychiatric AND physical symptoms—especially if you’ve had flea, tick, or animal exposure—it’s worth exploring Bartonella testing with a knowledgeable doctor.
The Big Picture: Rethinking Mental Health
We can’t afford to keep ignoring infections when it comes to mental health. If Bartonella and other pathogens can trigger psychiatric symptoms, then the standard model of mental illness is incomplete.
If you (or someone you love) are struggling with treatment-resistant mental health symptoms, and nothing is working—maybe it’s time to ask:
🦠 Could an infection be part of the problem?
🦠 Would testing for Bartonella, Borrelia, or Babesia make sense?
🦠 What if the right treatment could actually help?
Mental illness isn’t just about emotions or brain chemistry—it can be a sign of deeper physiological dysfunction. When the body is inflamed, infected, or out of balance, the brain suffers too. It’s time to treat the whole system, not just the symptoms.