Treatment-Resistant Schizophrenia: What It Means and How It’s Treated

Schizophrenia can be challenging to treat. About one-third of people with the condition have what’s called treatment-resistant schizophrenia (TRS). This means they don’t respond well to antipsychotic medication, and their schizophrenia symptoms remain largely uncontrolled.

Although there’s no cure for schizophrenia, long-term treatment of the condition can help manage symptoms, reduce relapses, and improve quality of life.

Fortunately, TRS can improve for many people when treatment barriers are addressed. These barriers may include medication side effects or trouble taking medication as prescribed. Finding the right medication plan can also help.

What Is Treatment-Resistant Schizophrenia?

Treatment-resistant schizophrenia is generally defined as schizophrenia that doesn’t respond adequately to two courses of antipsychotic medications. Specifically, people with TRS need to have had treatment with two different antipsychotic drugs for at least six weeks each with proper dosage.

Schizophrenia may be considered treatment-resistant if symptoms continue to cause distress or interfere with daily life despite these medication trials.

The condition is best diagnosed by a psychiatrist using a clinical assessment, which may include symptom-rating scales that measure schizophrenia symptoms over time.

TRS can occur at any time in the course of schizophrenia. Some people have TRS when they first experience psychosis (a loss of contact with reality, which may involve hallucinations or delusions). Others may develop TRS later if medication stops working.

TRS that appears at the beginning of schizophrenia may be linked with a more severe illness course and can indicate problems with neurodevelopment (brain development).

Some researchers are studying whether TRS could be a subtype of schizophrenia that has distinct biological characteristics. For instance, people with TRS have been found to have less gray matter in the brain, which controls functions such as speech, reasoning, and emotions, and more white matter, which helps different parts of the brain communicate.

Why Standard Antipsychotic Medication May Not Work

There are several reasons why a person with schizophrenia may not improve enough with standard antipsychotic medication.

Sometimes, symptoms continue despite an adequate trial of medication. In other cases, schizophrenia may only appear treatment-resistant because of factors that can be identified and addressed.

Chemical Imbalances

Researchers have linked schizophrenia with chemical imbalances in the brain, including the neurotransmitter dopamine (a chemical messenger that helps brain cells communicate). Many standard antipsychotic medications work by affecting dopamine activity in the brain.

Dopamine helps regulate several functions, including:

• Motivation
• Decision-making
• Mood
• Motor control (muscle movement)

Higher dopamine activity in certain parts of the brain has been linked with “positive” symptoms of schizophrenia, such as delusions and hallucinations. Positive symptoms are experiences that are added, such as seeing or hearing things that aren’t there or believing things that aren’t true.

Lower dopamine levels may be linked to cognitive and “negative” symptoms of schizophrenia. These may include low motivation, social withdrawal, and problems with memory or attention. However, these symptoms are complex and may involve more than dopamine.

Second-generation antipsychotic medications may help reduce symptoms by changing how dopamine and other brain chemicals work.

Some research suggests that people with treatment-resistant schizophrenia may not have the same dopamine-related challenges seen in other forms of schizophrenia. This may explain why medication that blocks certain dopamine receptors may not work in people with TRS.

Dopamine Hypersensitivity

After long-term use of antipsychotic medication, some people’s brains may become more sensitive to dopamine. This is called dopamine hypersensitivity. Some researchers think dopamine hypersensitivity may be different from TRS.

Some people with dopamine hypersensitivity may need a change in their treatment plan, such as a dose adjustment or a different medication. Medication changes should only be made with guidance from a psychiatrist or another healthcare professional.

Other Neurotransmitters

There’s some evidence that other neurotransmitters, such as glutamate and gamma-aminobutyric acid (GABA), may play a role in dopamine imbalances in people with TRS.

For instance, some people with TRS have shown higher levels of glutamate, a neurotransmitter that helps regulate various brain functions, including memory and learning. As a result, they may not respond to standard antipsychotic medications.

Some research has indicated that people with treatment-resistant schizophrenia may have genetic variations that affect neurotransmitters such as glutamate and dopamine.

Chronic Inflammation

Some research has shown that chronic inflammation and oxidative stress may also be associated with treatment resistance. Chronic inflammation develops when the immune system stays active for a long time, which may harm healthy cells.

Oxidative stress also damages cells and may be affected by environmental factors such as smoking tobacco, excessive alcohol consumption, or psychological stress.

False Treatment-Resistant Schizophrenia

In some cases, other factors may cause schizophrenia to look treatment-resistant when it’s not true TRS. This is sometimes called “pseudo-resistance.”

Some situations that can cause schizophrenia to look like TRS include:

• Not taking medication as prescribed, which may happen for many reasons, including side effects or trouble remembering doses
• Having symptoms that may not be caused by schizophrenia
• Being treated with a dose that is too low or not taken long enough to work
• Having other physical or mental health conditions that can interfere with treatment

What Are the Treatment Options for Treatment-Resistant Schizophrenia?

Researchers still don’t fully understand TRS. As of June 2026, clozapine is the only antipsychotic medication approved by the U.S. Food and Drug Administration (FDA) specifically for treatment-resistant schizophrenia. This medication has been shown to improve positive, negative, and cognitive symptoms of schizophrenia in some people with TRS.

Clozapine has also been found to reduce suicide, mortality (death), and hospitalizations among people living with TRS. Delayed treatment of TRS can lead to a poorer outcome.

Note: If you or someone you know needs help, you can contact the 988 Suicide & Crisis Lifeline by calling or texting 988 or chatting online.

Although clozapine can be an effective treatment for TRS in many cases, research shows that it’s not widely prescribed. The main reasons the drug is underused for TRS are:

• Limited training or experience among some doctors in diagnosing TRS and prescribing clozapine
• Concerns about side effects and the need for regular monitoring
• Challenges with taking medication consistently

If your schizophrenia symptoms aren’t well managed with standard antipsychotics, talk with your psychiatrist or another mental health professional about whether you should be evaluated for TRS and clozapine eligibility.

Clozapine requires careful prescribing, regular monitoring, and a plan for managing possible side effects.

Side Effects of Clozapine

All medications have a risk of side effects. One key reason clozapine is underused is the risk of serious side effects and the need for regular monitoring, including blood tests.

Common side effects may include:

• Drowsiness
• Tachycardia (fast heartbeat)
• Dizziness
• Constipation
• Nausea and vomiting
• Weight gain
• Insomnia

Less common and more serious side effects may include:

• Low white blood cell counts, including leukopenia, neutropenia, or agranulocytosis (very low levels of certain infection-fighting white blood cells)
• Seizures
• Pneumonia
• Severe constipation or slowed movement in the digestive tract, which can rarely become life-threatening
• Heart problems, including myocarditis (heart muscle inflammation), cardiomyopathy (weakening of the heart muscle), heart failure (when the heart can’t pump blood as well as the body needs), cardiac arrest (when the heart suddenly stops beating), or sudden death
• Arrhythmias (abnormal heart rhythms)
• Syncope (fainting), which may be related to low blood pressure

Many common side effects of clozapine may be reduced by starting with a low dose and increasing it slowly, as directed by a doctor. Noticing and treating common clozapine side effects early may help lower the risk of some serious complications.

If your doctor has recommended clozapine for TRS, talk with them about the possible benefits, side effects, and monitoring plan. It’s also important to ask what symptoms should prompt a call to the doctor or urgent medical care.

In one study, 87 percent of people taking clozapine for TRS felt the benefits outweighed the risks of the medication, despite having to undergo frequent blood tests to monitor white blood cell counts.

Other Treatment Options

Approximately 40 percent to 70 percent of people with TRS don’t have enough improvement with clozapine, even when it is taken as prescribed and at an adequate dose. These cases are known as ultra-treatment-resistant schizophrenia (UTRS).

In cases of UTRS, treatment with clozapine may be combined with additional treatment. Other treatment options that may be added to a treatment plan for UTRS include:

• Another antipsychotic medication or electroconvulsive therapy (ECT, a treatment that uses small electrical currents to affect brain activity) for ongoing positive symptoms
• An antidepressant for depression or certain negative symptoms
• Another antipsychotic or mood-stabilizing medication if aggression continues

Despite these treatment options, UTRS can be very difficult to treat, and evidence is still limited on the best approach.

Nonmedication Treatment of TRS

Other nonmedication treatment options may be helpful as part of a broader treatment plan for people with treatment-resistant schizophrenia. These options do not replace antipsychotic medication but may help with symptoms, functioning, or quality of life.

Nonmedication interventions include:

• Psychotherapy, such as cognitive behavioral therapy (CBT) or acceptance and commitment therapy (ACT), which may help people manage distressing thoughts, symptoms, and daily challenges
• Noninvasive stimulation, which uses electrical current or magnets to stimulate the brain without surgery
• Healthy lifestyle changes, such as a well-balanced diet and regular physical activity, to help manage metabolic issues (such as weight gain, blood sugar changes, or cholesterol changes) that can occur with schizophrenia or some antipsychotic medications
• Peer-led support groups, which may help people feel less alone and share coping tips for living with schizophrenia and TRS

Always seek advice from your healthcare provider or psychiatry team before taking any dietary supplements, because supplements can interact with medications or cause unwanted side effects.

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