By the end of their first year on GLP-1s, more than half of patients stop taking the medication.

There are a number of reasons for this, including high costs, unpleasant side effects and satisfaction with the weight they’ve already lost. The catch: stop taking GLP-1s, and the weight is likely to come back fast.

And that’s not all — your mind can suffer too after stopping the jab, according to new reports.

Research is just beginning to uncover the psychiatric impacts of stopping a drug that could be affecting how the brain processes mood and rewards.

New case reports published in The Primary Care Companion CNS Disorders detail the stories of two men who suffered psychiatric effects after stopping the weight loss drug.

Hallucinations

A 61-year-old man stopped tirzepatide (sold under the brand names Mounjaro and Zepbound) in August 2025 because of nausea.

Two months later, he was hospitalized for worsening confusion and erratic behavior.

Doctors noted he was experiencing paranoia, auditory and visual hallucinations and Cotard’s delusion, a condition when the patient believes they are dead or do not exist. These symptoms met the criteria for a psychotic disorder.

Although he’d had a history of depression, his condition worsened significantly in the month prior to hospitalization.

Tests on his cerebrospinal fluid, along with brain MRIs and electroencephalogram, all came back normal, ruling out several other causes. Doctors told him to continue his antidepressant (Zoloft) and put him on two other antipsychotics (Zyprexa and Haldol).

While his psychotic symptoms and depression initially improved enough for him to return home, he was readmitted weeks later for depression with catatonic features, becoming motionless and unresponsive.

Ultimately, he required inpatient care and was treated with electroconvulsive therapy.

Mania

A 52-year-old patient stopped the same medication (tirzepatide) abruptly in September 2025 after significant weight loss — he had shed 100 pounds over six months.

Just one month later, he was admitted to the hospital for erratic behavior and mood swings.

While he had a history of anxiety, his behavior after quitting the drug was far more concerning and met the criteria for a manic episode. His symptoms included fast, continuous, incoherent speech, impulsivity, irritability and grandiosity — an unrealistic sense of uniqueness, power or superiority.

Mania can be dangerous, especially because the patient may feel invincible and expose themselves to dangerous situations like reckless driving. Furthermore, the excessive energy combined with a neglect of sleep and food can put extreme strain on the body.

Once again, his test results came back normal, aside from a low vitamin B12 level. He was given the antipsychotic Risperdal and transferred to a psychiatric facility.

What’s going on?

GLP-1s act on more than just your digestive system — they also reach deep into the brain.

Research from the University of Virginia suggests the drugs affect a brain circuit involved in processing emotions, specifically how the brain rewards eating high-calorie foods with dopamine, the neurohormone that drives motivation, desire and pleasure.

“These medications impact neurotransmitters, and so they can have an impact on mood,” Amy Walters, a psychotherapist who works with people with metabolic disease, told the American Psychological Association.

The authors of the two case studies note that sudden mood or psychotic symptoms after stopping the medication could be “an underrecognized clinical phenomenon,” calling for more attention and research into how exactly GLP-1s affect our brain.

They suggest the drugs could be causing inflammation in the central nervous system, affecting dopamine production, and contributing to psychotic symptoms in at-risk patients.

The authors also point out that both patients had a history of mental health issues (depression and anxiety, respectively), which may play a role in whether these symptoms develop.

Ultimately, they urge doctors to be aware of this potential side effect when patients discontinue treatment.