Is schizophrenia more common in men than in women? Does it usually start around a certain age? And do things like your race or location raise your chances of getting it?
The field of epidemiology can help answer these questions. It’s a branch of science that looks at how often conditions and diseases affect different groups of people and why. Medical experts can then use this information to plan and figure out ways to prevent or manage diseases.
An estimated 1% of people around the world live with schizophrenia, a mental illness that affects how you think, feel, and act. The number of new cases per year is about 1.5 per 10,000 people. Here’s more on the epidemiology of schizophrenia.
When Do Schizophrenia Symptoms Usually Start?
Symptoms tend to start in your late teens, 20s, or early to mid 30s. Men may be more likely to get their first symptoms or their first bout of psychosis earlier than women do.
It’s rare for someone to start showing symptoms as a child or when they’re over 45 years old.
Is Schizophrenia More Common in Women or Men?
Women and men get this brain disorder in about the same numbers. Slightly more men get diagnosed with the condition. Women often get diagnosed later in life than men.
In general, the clinical signs of schizophrenia are less severe for women. Some research suggests that the course of the disease tends to be worse in men.
Does Race Play a Role?
Researchers haven’t yet identified racial differences where schizophrenia is concerned.
Is Schizophrenia More Common In Immigrants?
Many studies in several countries have observed that the disorder happens more often among people who’ve immigrated, compared to native-born people. The higher risk seems to apply to second-generation immigrants, too. The exact reasons for this link aren’t clear, but researchers have some theories about it. One is that schizophrenia may be overdiagnosed in immigrants.
Another theory involves stress. Stress can play a role in the development of schizophrenia in people who have a genetic or biological risk for the disorder. And moving to a new country can be very stressful.
Some research suggests that groups of immigrants who face more discrimination may have higher rates of schizophrenia than those who face less discrimination. Researchers have observed this link in Ethiopian people who moved to Israel, Moroccan people who moved to the Netherlands, and Caribbean people who moved to the United Kingdom.
A third theory suggests that immigrants may have a higher risk for schizophrenia partly due to being low on vitamin D, especially among people who move to latitudes farther north. Your skin makes a lot less vitamin D from the sun if you live in northern latitudes (like the New England region of the U.S.). A lack of the “sunshine vitamin” is linked with schizophrenia.
What Else Might Up Your Risk?
Some of the risk factors for schizophrenia are:
Genetics. Your genes and your environment both play a role. But your chances of getting schizophrenia may be more than six times higher if one of your parents, siblings, or another close relative has it.
Environment. Your risk could also go up if you’re exposed to certain viruses or to malnutrition before you’re born, especially during the first and second trimesters in the womb. Some research also suggests a link between autoimmune disorders and people developing psychosis. An autoimmune disorder is a condition in which your immune system goes haywire and attacks healthy cells by mistake.
Some research ties living in a city or town to a higher risk for schizophrenia. Researchers aren’t sure what things in an urban environment might raise someone’s odds of getting the disorder. But they think the higher risk applies to people whose genes already raise their odds of developing schizophrenia.
Brain chemicals. Problems with some of the chemicals your brain makes, including certain neurotransmitters, may play a role in schizophrenia. Neurotransmitters are chemicals that let your brain cells communicate with each other. Networks of neurons are probably involved, too.
Drug use. Some research suggests that taking mind-altering drugs when you’re a teen or a young adult can make you more likely to get schizophrenia. For example, smoking marijuana at these ages may raise your chances for psychotic episodes later.
The link between schizophrenia and pot use is stronger the earlier in life someone starts smoking marijuana, the more heavily they use it, and the higher the amount of THC (the mind-altering ingredient that gets you high).
Smoking cigarettes. This habit has also been linked with schizophrenia. Smoking may play a role in raising the risk for the disorder, or there might be a shared, underlying risk factor for both developing schizophrenia and for lighting up.
