Schizophrenia is a serious mental disorder in which people interpret reality abnormally. Schizophrenia may result in some combination of hallucinations, delusions, and extremely disordered thinking and behavior that impairs daily functioning, and can be disabling.
Worldwide, about 1 percent of the population is diagnosed with schizophrenia, and approximately 1.2% of Americans (3.2 million) have the disorder. About 1.5 million people will be diagnosed with schizophrenia this year around the world. In the United States, this means about 100,000 people will be diagnosed, which translates to 7.2 people per 1,000 or about 21,000 people within a city of 3 million who are likely to be suffering from schizophrenia.
People with schizophrenia require lifelong treatment. Early treatment may help get symptoms under control before serious complications develop and may help improve the long-term outlook.
Schizophrenia involves a range of problems with thinking (cognition), behavior and emotions. Signs and symptoms may vary, but usually involve delusions, hallucinations or disorganized speech, and reflect an impaired ability to function. Symptoms may include:
- Delusions. These are false beliefs that are not based in reality. For example, you think that you’re being harmed or harassed; certain gestures or comments are directed at you; you have exceptional ability or fame; another person is in love with you; or a major catastrophe is about to occur. Delusions occur in most people with schizophrenia.
- Hallucinations. These usually involve seeing or hearing things that don’t exist. Yet for the person with schizophrenia, they have the full force and impact of a normal experience. Hallucinations can be in any of the senses, but hearing voices is the most common hallucination.
- Disorganized thinking (speech). Disorganized thinking is inferred from disorganized speech. Effective communication can be impaired, and answers to questions may be partially or completely unrelated. Rarely, speech may include putting together meaningless words that can’t be understood, sometimes known as word salad.
- Extremely disorganized or abnormal motor behavior. This may show in a number of ways, from childlike silliness to unpredictable agitation. Behavior isn’t focused on a goal, so it’s hard to do tasks. Behavior can include resistance to instructions, inappropriate or bizarre posture, a complete lack of response, or useless and excessive movement.
- Negative symptoms. This refers to reduced or lack of ability to function normally. For example, the person may neglect personal hygiene or appear to lack emotion (doesn’t make eye contact, doesn’t change facial expressions or speaks in a monotone). Also, the person may lose interest in everyday activities, socially withdraw or lack the ability to experience pleasure.
Symptoms can vary in type and severity over time, with periods of worsening and remission of symptoms. Some symptoms may always be present.
In men, schizophrenia symptoms typically start in the early to mid-20s. In women, symptoms typically begin in the late 20s. It’s uncommon for children to be diagnosed with schizophrenia and rare for those older than age 45.
Can you develop schizophrenia through drugs?
Generally, drugs do not directly cause schizophrenia, but studies have shown drug misuse increases the risk of developing schizophrenia or a similar illness. Certain drugs, particularly cannabis, cocaine, LSD or amphetamines, may trigger symptoms of schizophrenia in people who are susceptible.
Many people with substance-induced psychoses will later transition to a diagnosis of schizophrenia, but estimates vary widely between early psychosis services and population-based registers. A recent review found that 21% of people with first-episode substance-induced psychosis later received a diagnosis of schizophrenia or schizoaffective disorder.