What Is Schizophrenia? Symptoms, Causes, Diagnosis, and Treatment

Schizophrenia affects fewer than 1 percent of adults in the United States, according to the National Institute of Mental Health (NIMH). (1)

This serious psychiatric disorder is one of the most disabling mental health issues. It can cause disordered thinking, delusions, and hallucinations. It affects how a person feels, thinks, and behaves, per the NIMH. (2)

Nonetheless, it’s possible for people with schizophrenia to live relatively full and satisfying lives.

There are treatments available to help reduce the symptoms of schizophrenia, although coping with the disease can be a lifelong struggle, and it has no cure, notes the National Alliance on Mental Illness (NAMI). (3)

Schizophrenia symptoms usually first appear early in life, during a person’s late teen years through their early thirties. Some people go through a “prodromal period” during which they do not display symptoms of schizophrenia but may have mood symptoms, withdraw socially, or be irritable. People with schizophrenia may display unusual behaviors and symptoms that can be upsetting for friends and family. These symptoms include:

• Hallucinations (when a person sees, hears, smells, or feels things that aren’t there)
• Delusions (illogical or untrue beliefs)
• Disorganized thinking and speaking
• Unusual body movements
• Problems with memory, attention, and concentration

Learn More About Signs and Symptoms of Schizophrenia

Experts have long debated the causes of schizophrenia, including whether schizophrenia is hereditary. There doesn’t appear to be just one cause of schizophrenia.

Is Schizophrenia Genetic?

Researchers now believe several genetic changes and other factors can increase the risk of schizophrenia. (2)

Risk factors for schizophrenia may include the following:

Genetics Certain genes have been linked to an increased risk of schizophrenia, but no single gene appears to be responsible for the disease.

Defects in those genes may increase the risk of schizophrenia by causing disturbances in the connections between brain cells.

In 2014, more than 300 scientists from around the world compared the genomes of 37,000 people with schizophrenia with more than 113,000 people without the disease in the biggest-ever genetic schizophrenia study. They found 128 distinct gene variants that were associated with schizophrenia. They reported their findings in the journal Nature. (4)

Schizophrenia tends to run in families, though not everyone who has a parent with schizophrenia will get the disease. People who have a parent or sibling with schizophrenia have about a 6 times higher risk of developing schizophrenia than the general population. (2)

Among people with schizophrenia, most of the risk of developing the disorder (80 percent) seems to be related to genetic factors (which include particular genotypes, variations in genomes, and family history), according to a study of Danish twins published in the March 2018 issue of Biological Psychiatry. (5)

The family link is most evident in identical twins. If one twin is diagnosed with schizophrenia, the other has as much as a 46 percent chance of developing the disease, per Stat Pearls. (6)

Brain Chemicals Problems with certain chemicals in the brain may increase your risk of developing schizophrenia. (3) These chemicals, called neurotransmitters, help brain cells in different parts of the brain communicate with one another.

Uterine Environment Researchers have linked exposure to certain viruses or malnutrition in the womb to schizophrenia. (3)

Drug Use Some scientific studies suggest that using mind-altering drugs like marijuana or methamphetamine, especially during the teenage years and early adulthood, can increase the risk of schizophrenia. (3)

While many of the symptoms can be controlled over time with proper treatment, symptoms of schizophrenia may be severe, and schizophrenia can be difficult to diagnose. That’s partially because people with schizophrenia symptoms may not realize they have it and may not take themselves to a doctor for treatment. (4)

Schizophrenia Testing and Diagnosis

No single, definitive test exists for schizophrenia. Thorough clinical interviews are used to diagnose the disease. A doctor will test for — or diagnose — schizophrenia by ruling out other medical conditions that may be causing symptoms.

Other conditions that can be associated with psychotic symptoms include:

• Legal or illegal drug use, including marijuana; substance use
• Bipolar disorder
• Depression
• Schizoaffective disorder
• Medication interactions (combining certain drugs that causes hallucinations and other symptoms similar to schizophrenia)
• Vitamin deficiencies, most notably B12
• Infectious disease, such as HIV and syphilis
• Autoimmune disease, like lupus, hypo- or hyperthyroidism, or autoimmune encephalitis
• Liver disease
• Neurological disorders, including seizures, strokes, and neurocognitive illness
• Brain tumors or other cancers

The process of testing and diagnosis will include:

Psychological Evaluation A doctor or mental health worker will ask you a range of questions about your thoughts, moods, delusions, hallucinations, and substance use. (7) This evaluation is considered the most important part of the diagnostic assessment.

Medical Tests A health worker may draw your blood for tests that can help rule out other conditions.

These tests will also screen for any alcohol or drugs in your system that may be contributing to your symptoms.

Your doctor may also recommend imaging studies of your head, such as a computerized tomography (CT) scan or magnetic resonance imaging (MRI).

A diagnosis of schizophrenia requires that some symptoms persist for six months or longer, with two or more of the symptoms occurring most of the time over a one-month period.

At least one of these symptoms must be delusions, hallucinations, or disorganized speech. (7)

First Episode Psychosis

Psychosis is defined as a break with reality. It can involve hearing voices, experiencing hallucinations, or having paranoia and other delusional thoughts. (5)

About 3 in 100 people will experience an episode of psychosis in their lifetime, according to the NIMH. (8)

Not everyone who experiences a psychotic episode has a mental illness. But schizophrenia is the most common cause of early psychosis — especially in teens and young adults. (3)

Psychosis can make it difficult for someone to tell what’s real and what isn’t. The changes in thoughts and perceptions can be gradual. People experiencing psychotic symptoms for the first time may not understand what’s happening. They may feel confused or distressed.

In these cases, friends, family members, or others in the community, including police officers, may be the first to spot psychotic behaviors.

It’s best to seek medical treatment immediately if you or someone you know might be experiencing signs of psychosis or schizophrenia. Such signs may not be cause for alarm, though it’s best to get assessed by a medical doctor. (3)

Early diagnosis — and prompt treatment — can greatly increase the chances that medication and other schizophrenia treatments will work effectively. (3)

While many of the symptoms can be controlled over time with proper treatment, there is no cure for schizophrenia.

Most people with schizophrenia will require medication, psychotherapy, and social services long term. In most cases, schizophrenia requires ongoing treatment, even after symptoms subside. (7)

Over the past 30 years, along with identifying the more than 125 genes that may increase the risk of schizophrenia, researchers have also begun finding novel pathways and making other discoveries that may help identify new targets for drug therapy.

There is no cure for schizophrenia, and as with many diseases that can be managed but not cured, early detection and treatment are important.

Seek medical treatment if you or someone you know might be experiencing signs of psychosis or schizophrenia. Early treatment can improve a person’s chance for a successful recovery. What’s more, proper treatment helps minimize symptoms and improve quality of life. Yet even after symptoms have ceased and schizophrenia is managed, most people with schizophrenia require ongoing drug and nondrug treatment.

Medication Options

Antipsychotic drugs help relieve hallucinations, delusions, and thinking problems. They’re often used to treat schizophrenia.

The drugs change the way that certain brain chemicals, or neurotransmitters, act.

Alternative and Complementary Therapies

A team approach called coordinated specialty care, involving early intervention after the onset of a first episode of psychosis with a coordinated, team-based approach and low doses of antipsychotic medication, has shown to be effective.

A coordinated specialty care approach may involve support from people trained in psychotherapy, family support, medication management, as well as work or education support.

Other therapies for schizophrenia include cognitive behavioral therapy, peer support groups, and rehabilitation programs that stress skills that can help patients function in their communities.

Learn More About Schizophrenia Treatment and Medication

People with schizophrenia have higher rates of some psychiatric disorders too.

Some psychiatric disorders that are more common in people with schizophrenia include the following:

• Depression
• Anxiety
• Alcohol and other substance abuse disorders

The rate of suicide is higher among people with schizophrenia than in the general population. People with known schizophrenia accounted for 5.4 percent of suicides in the United States in 2015, according to the Centers for Disease Control and Prevention. (9)

Studies suggest that those with schizophrenia are at higher risk of developing cardiometabolic diseases, particularly diabetes. Part of the increased risk is related to medication, research shows, but some is related to the disease itself.

Schizoaffective disorder is closely related to schizophrenia. It acts like a combination of schizophrenia and either depression or bipolar disorder.

What Is Schizoaffective Disorder?

People with schizoaffective disorder typically show symptoms of a mood disorder, such as mania or depression, alongside schizophrenia symptoms.

In the past, the process of diagnosing schizoaffective disorder may have been imprecise. Today, there is a distinction between having schizophrenia and mood episodes and having schizoaffective disorder.

Because the symptoms can overlap, it is not always clear whether a person has bipolar disorder or depression with psychotic features, or a schizophrenia-like illness, such as schizophrenia or schizoaffective disorder.

Overuse of stimulants — including methamphetamine (meth) and amphetamine and dextroamphetamine (Adderall, used to treat ADHD) — can cause drug-induced psychosis and schizophrenia-like symptoms.

Learn More About Schizoaffective Disorder

Different Types of Schizophrenia

You may have heard of someone with paranoid schizophrenia or disorganized schizophrenia.

People with schizophrenia may show a number of symptoms, including delusions, hallucinations, and disorganized speech and behavior.

In the past, doctors split schizophrenia patients into five subtypes depending on their dominant symptoms. Guidelines published by the American Psychiatric Association in 2013 eliminated schizophrenia subtypes, because they weren’t helpful to doctors. (10) That’s because schizophrenia symptoms can change over time, and symptoms may overlap. The new guidelines opted instead for a broader schizophrenia definition.

Some schizophrenia symptoms include the following:

• Auditory or visual hallucinations (hearing or seeing things that aren’t there)
• Delusions or false beliefs
• Disorganized thoughts or behaviors
• Disorganized speech or “word salad” (words thrown together without sensible meaning)
• Social withdrawal
• Absent or inappropriate reactions or emotional responses
• Neglecting personal appearance or hygiene
• Profound lack of energy

Paranoid Schizophrenia

People with paranoid delusions are often said to have paranoid schizophrenia. Paranoid delusions may make it difficult for a person with schizophrenia to cooperate with treatment and can increase the likelihood of problems such as homelessness, notes the NAMI. (11)

Schizophrenia in Children

When schizophrenia develops in children younger than 13, it’s called childhood-onset or pediatric schizophrenia.

Pediatric schizophrenia is a very rare — and often very severe — form of the disorder. It’s estimated to affect about 1 in 40,000 people. (12)

Schizophrenia is difficult to diagnose in young children. Many of its typical symptoms resemble those of more common childhood disorders, including autism and attention deficit hyperactivity disorder (ADHD). (12) Another key difficulty in making the diagnosis in kids is distinguishing between true hallucinations or delusions and normal childhood imaginative play — having an imaginary friend, for instance, according to an article published in January 2014 in Health Psychology and Behavioral Medicine. (13)

RELATED: Early Schizophrenia Treatment Programs Multiply

The exact prevalence of schizophrenia is hard to measures, but the NIMH estimates that schizophrenia affects between 0.25 and 0.64 percent of U.S. adults, while the NAMI has put it closer to 1 percent. (3)

Men typically start to show symptoms of schizophrenia in their late teens or early twenties. Women tend to show symptoms a bit later, usually in their late twenties or early thirties. (3)

Men are about 1.4 times more likely to be diagnosed with schizophrenia than women. (7)

Research has found that Black men are up to 2.4 times more likely to be diagnosed with schizophrenia, but more research is needed to determine if their incidence of disease is actually higher or if other factors, such as racial or testing biases, are contributing to the disparity.

Schizophrenia can occur at any age, but it’s less commonly diagnosed for the first time in a person older than 40 or younger than 12.

Myth: People with schizophrenia have more than one personality.

One of the biggest myths about schizophrenia is that people with schizophrenia have split, or multiple, personalities.

Fact: Having multiple personalities, or split personalities, is a symptom of a different mental illness called dissociative identity disorder.

Experts say that the media is partially responsible for some public misconceptions about schizophrenia.

Myth: People who have schizophrenia are dangerous.

Movies and television shows often perpetuate the myth that all people with schizophrenia are dangerous. This type of misunderstanding can be harmful for people with schizophrenia.

Fact: Most people with schizophrenia are not dangerous to others.

Some people with schizophrenia may have violent outbursts, and there’s a small subset of people with schizophrenia who can be dangerous.

The risk of harm to others is increased in people who are not currently in treatment, as well as people who are acutely psychotic, often with paranoid or other delusions involving others potentially harming them in some way.

Overall, the rate of violence committed by people with schizophrenia is very small; in fact, people with schizophrenia are more likely to be victims of violence as opposed to perpetrators.

As with everyone, when a person with schizophrenia uses drugs or alcohol, the risk of violence directed toward others increases.

However, most people with schizophrenia pose no danger to others. The vast majority of people with schizophrenia tend to withdraw from society when they are experiencing symptoms.

Learn More About Schizophrenia Myths and Facts

Myths, false information, and misunderstandings about a serious disease such as schizophrenia can be especially troubling for newly diagnosed people and their support network. Take advantage of credible medical resources, such as the National Alliance on Mental Illness and the National Institute of Mental Health. Both are excellent resources for those looking to find treatment and support for schizophrenia in their local area.

Learn More About Additional Resources and Support for Schizophrenia