Schizophrenia – Causes, Signs and Symptoms



Schizophrenia is a complex and disabling psychiatric disorder that affects a person’s ability to distinguish between real and unreal experiences, think logically, have normal emotional responses and behave appropriately.

Patients can be diagnosed with schizophrenia at any age, but the condition most often develops between the ages of 16 and 25 years. There are several types of schizophrenia, including paranoid, disorganized, catatonic, undifferentiated and residual. Depending on the type of schizophrenia, patients may report hearing voices that others cannot hear, believing their minds are being read or thinking that others are plotting to harm them.

The exact cause of schizophrenia is not known, but mental health experts believe the condition has some connection to genetic and environmental factors. Patients with schizophrenia usually first develop symptoms in adolescence or early adulthood. The condition occurs in about 1 percent of the U.S. population, according to the National Institute of Mental Health.

Schizophrenia can be difficult to diagnose because its symptoms are often similar to those of other mental illnesses and symptoms may start as mild and get worse over a long period of time. Physicians will usually rule out other disorders, such as bipolar disorder, psychotic depression, obsessive compulsive disorder, personality disorder or substance abuse, before making a definite diagnosis.

Schizophrenia can be difficult to diagnose because its symptoms are often similar to those of other mental illnesses. Physicians will usually rule out other disorders, such as bipolar disorder and substance abuse, before making a diagnosis. Diagnosing schizophrenia in children and adolescents can be especially difficult because hallucinations often occur in these age groups due to other causes. In addition, certain physiological diseases, such as brain tumors, can cause some symptoms that may be mistaken for a mental disorder.

People with schizophrenia are usually treated with antipsychotic medications. Psychosocial therapy may also be recommended to help people manage their illness and establish and maintain healthy relationships.

People with schizophrenia can usually control their symptoms with appropriate treatment, and should expect to recover sufficiently to work productively and have normal relationships. The idea that schizophrenia automatically means a person is disabled is not based in fact; however, it is frequently the case for those who refuse to work with their doctors and other treatment team members to develop a treatment plan and a medication plan that works for them.

About schizophrenia

Schizophrenia is a type of psychotic disorder (severe mental condition that causes the patient to lose touch with reality). People may develop schizophrenia alone, or it may occur in combination with other psychiatric or medical conditions.

This is only one of a number of illnesses that include psychotic symptoms. Losing touch with reality or having abnormal thoughts does not mean that someone has schizophrenia, and schizophrenia is not the same thing as a split personality, as some people believe because of the origin of the word “schizophrenia.”

Schizophrenia can be diagnosed at any age, but 75 percent of people with the disorder first develop symptoms between the ages of 16 and 25 years, according to the National Alliance on Mental Illness (NAMI). Schizophrenia rarely occurs before puberty, although cases in children as young as 5 years old have been reported. The illness is difficult to recognize in children and adolescents because hallucinations, the hallmark of schizophrenia, can be caused by a number of other unrelated conditions, and because its slow onset can lead to an assumption that it is a behavior problem.

About 1 percent of the U.S. population develops schizophrenia, according to NAMI. The illness affects men and women equally, although it often appears at an earlier age in males than females. Onset in males typically occurs between the late teens and early 20s. In females, onset usually occurs between the 20s or early 30s.

Schizophrenia may be related to development of a child’s brain during pregnancy. One theory is that changes before birth lead to faulty connections within the brain. These poor connections are dormant until puberty, when the brain undergoes dramatic changes, which can lead to the psychotic symptoms associated with the condition. There is, however, no direct scientific evidence that leads scientists and doctors to believe that there is a single cause for this illness.

The structure of the brain appears different in some patients as compared to the general population. Some of these differences include the following:

  • The fluid-filled cavities at the center of the brain (ventricles) are larger.

  • The volume of gray matter (which consists of the neurons, brain cells) is lower.

  • Some areas of the brain have abnormal metabolic activity.

It is important to note that not all patients with schizophrenia have these differences. Nor do all patients with these differences have schizophrenia.

Myths and misperceptions about schizophrenia

Patients are often stigmatized by lack of public understanding about schizophrenia. The disease is often confused with split personalities (dissociative identity disorder, DID), but they are different disorders. DID, which is rare, is characterized by the presence of two or more alternate personalities in one body, each having their own memories, behavior and relationships. Patients with schizophrenia may have strange and unpredictable behavior, but they do not have more than one personality.

Nor should schizophrenia be confused with two similarly named conditions: schizoid personality disorder (marked by withdrawn, solitary and emotionally detached behavior) or schizotypal personality disorder (marked by widespread social deficits and eccentric behaviors).

Another misperception about schizophrenia is that patients are violent. However, most people with schizophrenia are not prone to violence and often prefer to be left alone. Studies have demonstrated that if patients do not have a criminal record or substance abuse problem prior to developing schizophrenia, they are unlikely to commit crimes after becoming ill. Patients with paranoid schizophrenia are more likely to commit an act of violence, which is usually directed at a someone close to them or someone about whom they have delusions.

People with schizophrenia do abuse alcohol and drugs more frequently than the general population. However, most scientists do not believe that substance abuse causes schizophrenia. Also, some people who abuse drugs exhibit symptoms similar to those of schizophrenia, and patients are sometimes mistakenly thought to be under the influence of drugs. Drugs can also make the symptoms of schizophrenia worse, both directly because of the effect of the drug on the brain and secondarily because people who are using illegal drugs frequently do not take their medication as they should.

Nicotine is the most common form of substance abuse among patients with schizophrenia. Research has shown that people with schizophrenia are addicted to nicotine at three times the rate of the general population (75 to 90 percent versus 25 to 30 percent), according to National Institute of Mental Health (NIMH).

Types and differences of schizophrenia

There are five recognized types of schizophrenia:

  • Paranoid. Characterized by delusions (fixed false beliefs held by a person despite evidence to the contrary) in addition to other symptoms of schizophrenia, such as abnormal ways of thinking, and/or hallucinations. Typically, the onset of the disorder is later than with other types of schizophrenia, with some studies reporting an average age of 35 years. The complex of symptoms makes this paranoid schizophrenia — if the only symptom is delusions, it is a delusional disorder, not paranoid schizophrenia.

  • Disorganized. Characterized by disorganized behavior and speech. Expressions of emotion are often flat or inappropriate. Patients with this type of schizophrenia often deteriorate rapidly, talk gibberish and neglect personal hygiene and appearance. Frequently everything about their lives become disorganized.

  • Catatonic. Characterized by abnormal physical movements. Although some patients may exhibit motor (motion) activity that is speeded up, most patients exhibit slow motor activity, sometimes to the point of stupor. This type of schizophrenia may also be marked by negativism or peculiar behavior such as posturing (maintaining an unusual or awkward posture for a long period of time).

  • Undifferentiated. Patients who have been diagnosed with schizophrenia, but do not meet the characteristics of the paranoid, disorganized or catatonic types.

  • Residual. Patients who were previously diagnosed with schizophrenia but are no longer experiencing positive symptoms, such as catatonic behavior, delusions, hallucinations or disorganized speech or behavior. However, patients still experience some symptoms of mental illness, such as flat expressions of emotion, reduced speech output or lack of volition (capability of conscious choice, decision and intention).

There are also two conditions related to schizophrenia:

  • Schizophreniform disorder. This condition has similar symptoms except that they last from one to six months, compared to at least six months for schizophrenia, and it does not necessarily involve a decline in functioning. However, for many people the diagnosis of schizophreniform disorder represents a prodrome (beginning) stage of schizophrenia.

  • Schizoaffective disorder. Patients with this condition exhibit signs of schizophrenia as well as mood disorders such as depression or mania. Because the diagnosis is not clearly schizophrenia, but also does not have all the symptoms needed to diagnose a depression, anxiety disorder or bipolar disorder, it falls into this category.

Risk factors and potential causes of schizophrenia

The exact cause of schizophrenia is not known. Mental health experts believe that the condition results from a combination of genetic and environmental factors.

Schizophrenia tends to run in families. Although it occurs in about 1 percent of the general population, it occurs in 10 percent of people who have a first-degree relative (parent, brother or sister) with schizophrenia. People with a second-degree relative (aunt, uncle, grandparent or cousin) also develop schizophrenia at higher rates than the general population. People who have a twin with the disorder face the highest risk, with a 40 to 65 percent chance of developing schizophrenia, according to the National Institute of Mental Health (NIMH).

Genes have also been linked to an increased risk of schizophrenia. Genes are located on 23 pairs of chromosomes (rod-shaped structures found in the nucleus of a cell that contain hereditary material). People inherit two copies of each gene, one from each parent. However, scientists believe that each gene may play a small role in the development of the disorder and is not responsible for causing the disease by itself. Also, scientists are not able to predict who will develop the disorder simply by studying genes.

Recent research studies have also found an increased risk of schizophrenia, autism and certain other disorders in children born to a mother or father of advanced age. This risk is attributed to the declining genetic quality of aging eggs and sperm.

Environment has also been identified as playing a role. Possible environmental factors associated with the development of schizophrenia include:

  • Exposure to viruses or malnutrition in the womb.
  • Complications during birth, such as mild brain damage.
  • Toxoplasmosis, an infection with a common parasite carried by cats.
  • Psychosocial factors, such as stressful environmental conditions (e.g., malnutrition).

People with schizophrenia have an imbalance of the brain chemicals serotonin and dopamine. These chemicals are neurotransmitters, which allow nerve cells in the brain to send messages to each other. Everything we experience is the result of brain chemistry sending us messages. In schizophrenia, the input from other people and the environment does not result in the same messages that everyone else receives. An imbalance of brain chemicals can lead to hallucinations and paranoia, which respond to medication that corrects the imbalances.

Signs and symptoms of schizophrenia

Signs and symptoms of schizophrenia differ greatly among patients, but may be divided into three broad categories: positive, negative and cognitive.

Positive symptoms involve an excess or distortion of normal function. They usually involve a loss of contact with reality. They can be severe at times and hardly noticeable at other times. They include:

  • Hallucinations. A perception by the senses of something that is not actually there. They can involve any of the five major senses — vision, hearing, smell, touch or taste — although auditory (hearing) hallucinations are the most common. Many people with the disorder hear voices that may comment on their behavior, order them to do things, warn them of impending danger or talk to each other (usually about the patient).

  • Delusions. Fixed false beliefs of the person despite evidence to the contrary. Common types of delusions include:

    • Persecution. These are the most common. Patients believe they are being tormented, followed, tricked, spied on or ridiculed.

    • Referential. These are also common. Patients believe that references in books, song lyrics, newspapers or other areas are directed at them.

    • Grandeur. Patients believe they are persons of high status, such as a deity or a movie star.

    • Guilt. Patients believe they have committed a grave sin or mistake.

    • Ill health. Patients believe they have a bad disease.

    • Jealousy. Patients believe their spouses or partners have been unfaithful.

    • Passivity. Patients believe they are being controlled or manipulated by outside influences, such as radio waves.

    • Poverty. Patients believe they are facing destitution, even though they have a job or money in the bank.

    • Thought control. Patients believe ideas are being put into their minds by others.

  • Thought disorder. Patients often have unusual thought processes. They may have difficulty organizing thoughts or connecting them logically. Speech may be disorganized (sometimes called loose associations), or people may connect thoughts by rhymes or puns rather than logic. Thoughts also may be tangential, that is, the person may take the conversation in a totally different direction and have difficulty staying on any one topic.

  • Movement disorder. Patients with schizophrenia may be clumsy and uncoordinated. They may have involuntary movements or unusual mannerisms. These may occur as side effects of some antipsychotic medications, but as symptoms they occur even before someone takes any medication.

Negative symptoms involve a loss of normal emotional and behavioral functioning. Many of these symptoms are also symptoms of other medical disorders or may occur in healthy individuals. They include:

  • Flattened affect. Reduced range of emotion. This may include immobile facial expressions or monotonous voice.

  • Lack of pleasure in everyday activities (anhedonia).

  • Loss of ability to initiate and sustain planned activity (avolition).

  • Inability to sustain conversation, even when forced to speak (alogia).

Cognitive symptoms are often subtle and may be detected only when neuropsychological tests (specifically designed tasks used to measure a psychological function known to be linked to a particular brain structure or pathway) are conducted. Cognitive symptoms can greatly create big problems in a person’s ability to lead a normal life. They include:

  • Poor functioning. The ability to retain and interpret information and make decisions based on that information.

  • Inability to sustain attention.

  • Problems with memory. The ability to retain recently learned information and access it.

Patients with schizophrenia often neglect basic hygiene and need assistance with activities of daily living. Some patients’ ability to function in personal and job settings deteriorates over time. Other patients exhibit symptoms that come and go. Staying on medication and involved in treatment can help minimize symptoms.

Diagnosis methods for schizophrenia

The diagnosis of schizophrenia usually begins with a physical examination conducted by a physician, who will also review the patient’s medical history, including any family history of mental illness.

A physician may try to rule out other mental or physical illnesses that may be causing symptoms. Blood or urine tests may be conducted to determine whether medications, substance abuse or illness is contributing to symptoms. Some infections, cancers, nervous system disorders, thyroid disorders, immune system disorders, seizures and head trauma can produce psychotic symptoms. At times, imaging studies such as MRI may be ordered to rule out other conditions that can affect the brain.

A patient will be referred to a psychiatrist who can conduct a psychiatric evaluation, which should include a detailed description of signs and symptoms, a mental status examination and overview of social, family and psychiatric history. Patients with schizophrenia usually begin experiencing symptoms in late adolescence or early adulthood.

In general, a patient must be experiencing psychotic or “loss of reality” symptoms associated with schizophrenia for at least six months to be diagnosed with the disorder. The symptoms must be accompanied by a decreased ability to function in work, school, home and/or social settings.

Schizophrenia can sometimes be difficult to diagnose because many of its symptoms are also symptoms of other mental disorders, such as depression or bipolar disorder. Also, a person with schizophrenia may not be able to recognize the symptoms because they are not thinking straight. In some cases, patients are referred to medical professionals by family members or friends. With early diagnosis and treatment, however, the disorder can be managed more effectively, and some measure of recovery can occur.

Treatment options for schizophrenia

The cause of schizophrenia is largely unknown, and there is no known way to prevent or cure the disorder. The focus of treatment is often to control symptoms with minimal side effects from medication, and achieve the best recovery possible.

Patients are usually treated at home. However, they can be treated in a hospital if they experience acute symptoms, such as severe delusions or hallucinations, serious suicidal thoughts, an inability to care for themselves or if they are violent or threatening others as a result of their illness.

The most common treatment for schizophrenia is antipsychotic medication. Patients with schizophrenia sometimes stop taking medications because they feel better, forget to take them or dislike the side effects, or take them sporadically because they think regular use is not important. Following the physician’s directions for medications and communicating any problems to the physician is the most important thing to make sure there is adequate treatment.

In addition to medication, patients with schizophrenia may need psychosocial rehabilitation (therapy that involves addressing both social and psychological behavior). Research has shown that patients treated with rehabilitation and medication are best able to manage their illness.

Psychosocial treatment may include therapy to address substance abuse (common in people with schizophrenia), social and vocational training to help people work and live in the community, occupational therapy to increase independence with activities of daily living such as grooming and meal preparation and job skills, and illness management techniques to help patients understand their condition, identify signs of relapse and develop a plan in case relapse occurs.

It is very important that the therapy the person gets is appropriate for that individual’s needs. Some people are more disabled than others and need more basic therapy and vocational training. Others are well controlled on their medication and not only do not benefit from basic training and therapy, but can become very frustrated if they are “required” to participate and stop all of their treatments. Treatment should always be individualized to the needs of the person.

Cognitive behavior therapy may be helpful for patients whose symptoms continue even with medication. Cognitive therapists teach patients how to monitor the reality of their thoughts and perceptions, how to ignore auditory hallucinations and how to cope with apathy that can be immobilizing.

Self-help groups can provide comfort and support among members who share their experiences. Networking in groups can also generate social action when members unite and advocate for more research or treatment programs.

Studies show that after 10 years of treatment, 25 percent of patients recover completely, 25 percent improve a great deal and 25 percent experience some improvement. Fifteen percent of patients do not experience improvement and 10 percent die, usually by suicide or accident, according to National Alliance for the Mentally Ill (NAMI).

Schizophrenic people have a higher risk of suicide than the population at large. Threats of suicide or any activity that you think might be a suicide attempt or planning for suicide should be taken very seriously and evaluated by a professional.

People with schizophrenia often resist treatment because they believe that their hallucinations and delusions are real and that they do not need psychiatric help. Although laws differ from state to state, civil rights laws to protect patients with schizophrenia from being involuntarily committed into a mental health facility have become strict. If patients pose a danger to themselves or others and refuse to seek treatment, family members may have to call the police to transport the patient to the hospital. Once at the hospital, the patient will be evaluated by a mental health professional.

Patients with schizophrenia often need assistance from family members, friends and others to ensure that they continue to receive treatment and take their medications. Schizophrenia is a chronic disease. If patients stop taking medications, psychotic symptoms can reappear and may impair their ability to care for basic needs, such as food, clothing and shelter. Family and friends can also help patients set realistic goals for coping with their illness. It is important to show support and encouragement because patients who feel pressured or criticized often regress, making symptoms worse.

In very rare cases, electroconvulsive therapy (ECT) may be recommended by a psychiatrist to treat certain symptoms of schizophrenia. ECT is particularly useful for people with schizophrenia who have bad catatonic symptoms or hallucinations that do not respond to any medications and are life threatening. Most frequently, ECT is used for other psychiatric disorders.

Ongoing research for schizophrenia

The outlook for patients with schizophrenia has improved over the past 30 years because much knowledge has been gained in genetics, neuroscience and other related areas of science. Because of the variety of circumstances that may result in the disease developing, the underlying processes and the terms used to describe schizophrenia may evolve as research continues.

In addition, schizophrenia continues to be a major focus of research at the National Institute of Mental Health (NIMH). Research initiatives being undertaken at NIMH include:

  • Genes, Cognition and Psychosis Program. Uses animal models, molecular genetics, cell culture, postmortem studies and brain imaging techniques to investigate how genes can cause changes in the thought processes and influence the development of psychosis.

  • NIMH Genetic Study of Schizophrenia. Gathers genetic and environmental information from families with at least one member that has schizophrenia in an effort to determine what places family members at a higher or lower risk of developing the disorder.

  • NIMH Human Genetics Initiative and Genomic Resources Program. Collects data about families that have a history of mental illness in an attempt to learn more about the interaction between genetics and the environment, brain systems, neural circuits and other factors associated with mental illness.

  • Silvio O. Conte Centers for the Neuroscience of Mental Disorders. Supports six research teams dedicated to translating and integrating basic and clinical neuroscience on schizophrenia.

  • North American Prodromal Longitudinal Study. Follows teenagers at risk for developing schizophrenia. Some scientists believe that the development of schizophrenia can be slowed with early intervention.

  • Schizophrenia Research Forum. Web site developed by a group of science writers and web designers in collaboration with the Mental Health Research Association and the National Alliance for Research on Schizophrenia and Depression (NARSAD). The site will include new publications, a database of citations, research tools and live chats for scientists.

Questions for your doctor on schizophrenia

Preparing questions in advance can help patients have more meaningful discussions with physicians regarding their conditions. Patients may wish to ask their doctor the following questions about schizophrenia:

  1. Are my symptoms indicative of schizophrenia? Can they be caused by another health condition?

  2. How will you diagnose my suspected schizophrenia?

  3. If a family member has schizophrenia, how likely am I to get it too?

  4. What type of schizophrenia do I have?

  5. How is schizophrenia differentiated from other mental illnesses?

  6. Will I need medication to treat my schizophrenia?

  7. Are there any side effects with the type of medication prescribed?

  8. Should I receive therapy? What type of therapy would be best for me? For how long will I need to be in therapy?

  9. How soon after starting treatment will I see improvement in my symptoms?

  10. What are the chances that any of my children also will develop schizophrenia?

  11. I have a family member with schizophrenia. What are the best ways I can help?
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