Approximately 2.5 million Americans are diagnosed with schizophrenia. An individual with schizophrenia may have difficulty distinguishing between what is real and what is imaginary. This often manifests in socially unresponsive and withdrawn behavior, including trouble with emotional expression in social settings. While the illness may develop over months or years, symptoms usually emerge between the ages of 15 and 25 and often earlier in males than females. Symptoms may come and go in cycles.


The "positive symptoms" of schizophrenia are things that are "extra," or present to those with schizophrenia but not present to everyone else. For example, someone with schizophrenia may see or smell things that other people do not see or smell, or hear voices or sounds that other people do not hear.

Positive symptoms also include fixed false beliefs (sometimes called delusions). Someone may believe that they are being followed by the FBI or have been chosen for a special role in their faith community or government. Because they are struggling with these positive symptoms of schizophrenia, individuals with schizophrenia who do not receive effective treatment often are unable to develop the skills needed to live independently or thrive in society.

Some of the most serious symptoms of schizophrenia may be hard to see. Known as "negative symptoms," these include "losses" such as the loss of motivation, emotional expression, logical communications, ability to experience pleasure and even cognitive abilities. Because the first episode of schizophrenia typically appears at a time when young people are learning how to be adults, the long-term effects of these negative symptoms can have the greatest impact.

Research suggests that schizophrenia may have several possible causes:


Combination of many factors may cause anxiety disorders: Genetics. Schizophrenia isn’t caused by just one genetic variation, but a complex interplay of genetics and environmental influences. While schizophrenia occurs in 1% of the general population, having a history of family psychosis greatly increases the risk. Schizophrenia occurs at roughly 10% of people who have a first-degree relative with the disorder, such as a parent or sibling. The highest risk occurs when an identical twin is diagnosed with schizophrenia. The unaffected twin has a roughly 50% chance of developing the disorder.

Environment. Exposure to viruses or malnutrition before birth, particularly in the first and second trimesters has been shown to increase the risk of schizophrenia. Inflammation or autoimmune diseases can also lead to increased immune system

Brain chemistry. Problems with certain brain chemicals, including neurotransmitters called dopamine and glutamate, may contribute to schizophrenia. Neurotransmitters allow brain cells to communicate with each other. Networks of neurons are likely involved as well.

Substance use. Some studies have suggested that taking mind-altering drugs during teen years and young adulthood can increase the risk of schizophrenia. A growing body of evidence indicates that smoking marijuana increases the risk of psychotic incidents and the risk of ongoing psychotic experiences. The younger and more frequent the use, the greater the risk. Another study has found that smoking marijuana led to earlier onset of schizophrenia and often preceded the manifestation of the illness. Diagnosis
Research suggests that schizophrenia may have several possible causes:

Diagnosing schizophrenia is not easy. And usage of some medications can cause a person to have schizophrenia-like symptoms. The difficulty of diagnosing this illness is compounded by the fact that many people who are diagnosed, do not believe they have it. Lack of awareness is a common symptom of people diagnosed with schizophrenia, and greatly complicates treatment. While there is no single physical or lab tests that can diagnosis schizophrenia, a health care provider who evaluates the symptoms and the course of a person's illness over six months can help ensure a correct diagnosis. The health care provider will rule out other medical conditions such as brain tumors, and other psychiatric diagnoses, such as bipolar disorder. To be diagnosed with schizophrenia, a person must have two or more of the following symptoms occurring persistently in the context of reduced functioning:

  • Delusions
  • Hallucinations
  • Disorganized speech
  • Disorganized or catatonic behavior
  • Negative symptoms


There is no cure for schizophrenia, but it can be treated and managed in several ways.

  • Antipsychotic medications
  • Psychotherapy, such as cognitive behavioral therapy and assertive community treatment and supportive therapy
  • Self-management strategies and education
Related Conditions People with schizophrenia may have additional illnesses. These may include:
  • Substance abuse
  • Posttraumatic stress disorder
  • Obsessive-compulsive disorder
  • Major depression

Successfully treating schizophrenia almost always improves these related illnesses. And successful treatment of substance abuse, PTSD or OCD usually improves the symptoms of schizophrenia.