Schizophrenia

Symptoms of schizophrenia

Doctors group symptoms into three categories.

Positive symptoms (psychosis)

• Hallucinations: hearing voices others cannot hear is most common; seeing, feeling or smelling things that are not there also occurs. See hallucinations.
• Delusions: fixed false beliefs not shared by others, such as being followed, watched or plotted against (paranoia), having special powers, or that thoughts are being inserted or broadcast.
• Disorganized thinking and speech: jumping between unrelated topics, answers that do not fit the question, or incomprehensible speech.
• Disorganized or abnormal behavior: unpredictable agitation, inappropriate responses, or catatonia (reduced movement and responsiveness).

Negative symptoms

• reduced motivation and ability to start activities
• reduced emotional expression and speech
• reduced pleasure and interest
• social withdrawal
• neglect of self-care

Negative symptoms are often the most disabling and the hardest to treat.

Cognitive symptoms

• poor attention and concentration
• problems with working memory
• difficulty planning and organizing

Early warning signs

Before a first episode, many people go through a "prodrome" lasting months to years:

• withdrawing from friends and family
• dropping grades or job performance
• trouble concentrating
• sleep changes
• irritability, suspiciousness or unusual ideas
• reduced self-care
• odd or flat emotional responses

These signs are not specific, but early assessment matters: shorter time from first psychosis to treatment is linked to better outcomes.

Causes and risk factors

There is no single cause. Schizophrenia arises from a combination of:

• Genetics: the risk is about 10% with an affected parent or sibling, and about 40 to 50% for an identical twin. Many genes each contribute a small effect.
• Brain development: differences in brain structure and dopamine and glutamate signaling.
• Prenatal and birth factors: maternal infection or malnutrition, birth complications.
• Cannabis use in adolescence, especially high-potency and frequent use, raises the risk.
• Childhood adversity and trauma, migration, and urban upbringing.

Schizophrenia is not caused by parenting, and it is not "split personality".

Diagnosis

There is no blood test or scan for schizophrenia. A psychiatrist makes the diagnosis using DSM-5-TR criteria:

• two or more core symptoms (at least one being delusions, hallucinations or disorganized speech) for a significant part of a month
• continuous signs of disturbance for at least 6 months
• significant decline in work, relationships or self-care
• other causes excluded

Ruling out other causes

Doctors check for:

• substance-induced psychosis from cannabis, stimulants, hallucinogens or alcohol withdrawal
• medical conditions: thyroid disease, brain tumors, epilepsy, autoimmune encephalitis, infections, delirium
• other psychiatric conditions: bipolar disorder with psychotic features, schizoaffective disorder, severe depression with psychosis, PTSD

Assessment may include blood tests, drug screening, and brain imaging or EEG in selected cases.

Treatment

Coordinated specialty care

For a first episode, NIMH recommends coordinated specialty care: a team approach combining medication, psychotherapy, family education, case management and support for work or school. It improves outcomes and engagement.

Antipsychotic medicines

• Second-generation antipsychotics (such as aripiprazole, risperidone, olanzapine, quetiapine, lurasidone, paliperidone) and first-generation ones (such as haloperidol) reduce positive symptoms and prevent relapse.
• Long-acting injectables given every 2 weeks to 6 months help people who find daily tablets hard.
• Clozapine is the most effective medicine for treatment-resistant schizophrenia and reduces suicide risk; it requires regular blood count monitoring.
• Xanomeline-trospium, approved in 2024, works through a different (muscarinic) mechanism.

Side effects vary and include weight gain, diabetes and cholesterol changes, sleepiness, restlessness, stiffness, raised prolactin and, with long-term use, tardive dyskinesia. Regular monitoring and finding the right medicine and dose are important. Stopping medicine suddenly raises relapse risk.

Psychosocial treatments

• cognitive behavioral therapy for psychosis
• family psychoeducation, which reduces relapse
• social skills training and cognitive remediation
• supported employment (individual placement and support)
• assertive community treatment for people with frequent crises
• peer support

Physical health

People with schizophrenia have higher rates of heart disease, diabetes and smoking. Regular checks, help to stop smoking, exercise and healthy eating are part of care.

Outlook

The course varies. Some people have one or a few episodes with good recovery; others have ongoing symptoms. With early and sustained treatment, many people work, study, have relationships and live independently. Suicide risk is elevated, particularly early in the illness, so ongoing support is vital.

How to help someone with schizophrenia

• learn about the illness and treatment
• listen calmly; do not argue about delusions, but do not pretend to agree
• encourage treatment and offer practical help with appointments
• watch for relapse signs and agree a crisis plan
• take care of yourself; NAMI and other groups offer family programs

Frequently asked questions

What are the first signs of schizophrenia?

Early signs often include social withdrawal, declining performance at school or work, trouble concentrating, sleep changes, suspiciousness and unusual thoughts. These may precede hallucinations and delusions by months or years. Early assessment by a mental health professional is important.

Is schizophrenia genetic?

Genes play a significant role: having a parent or sibling with schizophrenia raises the risk to about 10%, compared with under 1% in the general population. But most people with a family history never develop it, and environmental factors also matter.

Can schizophrenia be cured?

There is no cure, but it is treatable. Many people achieve long periods of remission and good functioning with medication, therapy and support. Early treatment and staying on effective treatment give the best outcomes.

Are people with schizophrenia dangerous?

Most people with schizophrenia are not violent and are more likely to be victims of violence than perpetrators. The risk of violence is higher with untreated psychosis and substance use, which is one reason treatment and support matter.

What is the difference between schizophrenia and bipolar disorder?

Schizophrenia is mainly a disorder of thinking and perception, with psychosis and negative symptoms. Bipolar disorder is mainly a mood disorder, with episodes of mania and depression; psychosis can occur but usually only during mood episodes.