Research suggests that schizophrenia may have several possible causes:

• Genetics. Schizophrenia isn’t caused by just one genetic variation, but a complex interplay of genetics and environmental influences. Heredity does play a strong role—your likelihood of developing schizophrenia is more than six times higher if you have a close relative, such as a parent or sibling, with 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. Recent research also suggests a relationship between autoimmune disorders and the development of psychosis.
• 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.

With any condition, it's essential to get a comprehensive medical evaluation in order to obtain the best diagnosis. For a diagnosis of schizophrenia, some of the following symptoms are present in the context of reduced functioning for a least 6 months:

Hallucinations. These include a person hearing voices, seeing things, or smelling things others can’t perceive. The hallucination is very real to the person experiencing it, and it may be very confusing for a loved one to witness. The voices in the hallucination can be critical or threatening. Voices may involve people that are known or unknown to the person hearing them.

Delusions. These are false beliefs that don’t change even when the person who holds them is presented with new ideas or facts. People who have delusions often also have problems concentrating, confused thinking, or the sense that their thoughts are blocked.

Negative symptoms are ones that diminish a person’s abilities. Negative symptoms often include being emotionally flat or speaking in a dull, disconnected way. People with the negative symptoms may be unable to start or follow through with activities, show little interest in life, or sustain relationships. Negative symptoms are sometimes confused with clinical depression.

Cognitive issues/disorganized thinking. People with the cognitive symptoms of schizophrenia often struggle to remember things, organize their thoughts or complete tasks. Commonly, people with schizophrenia have anosognosia or “lack of insight.” This means the person is unaware that he has the illness, which can make treating or working with him much more challenging.

Schizophrenia means you have a split personality, you're violent, and you can't hold onto a job

Schizophrenia is a thought disorder. Patients diagnosed with schizophrenia do not present with a split personality, nor is it common for someone with the disorder to be violent, says Simon Rego, PsyD, chief psychologist at Montefiore Medical Center and Associate Professor of Psychiatry and Behavioral Sciences at Albert Einstein College of Medicine in New York City. And many individuals with schizophrenia are able to work. The National Alliance on Mental Illness estimates that as many as half of the two million Americans with schizophrenia can improve significantly or even recover completely if they get treatment.

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