Schizophrenia causes changes in a person’s thinking and behavior. Symptoms usually appear when people are in their 20s, though the average age of onset can vary.

One 2020 study found an average schizophrenia age of onset to be between 13.78 and 29.28 years old. Environmental, genetic, and other factors may affect the age of onset.

Additionally, the age of onset for schizophrenia may affect the condition’s course. Most studies show, for example, that people who develop schizophrenia in childhood or adolescence have more symptoms.

In addition to the onset of schizophrenia symptoms, many people with schizophrenia experience a prodrome. This is a group of mental health symptoms, such as depression, mood swings, and irritability, that may be present for months or even years before full-blown schizophrenia appears.

A 2014 study suggests that the schizophrenia prodrome may appear up to 9 years prior to the onset of the condition.

Knowing the average age of schizophrenia onset reveals little about whether or when an individual might develop this condition.

Keep reading to learn more about the average age of onset for schizophrenia, including early onset, late onset, and some early symptoms of the condition.

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Symptoms of schizophrenia usually appear late in adolescence or early in adulthood.

However, less noticeable symptoms of schizophrenia, such as erratic moods or depression, may occur many years prior to diagnosis. Doctors call this a prodrome. Prodromal symptoms may indicate that a person has a higher risk of developing schizophrenia.

Adults of all ages may have symptoms of schizophrenia. However, it is rare for symptoms to appear for the first time after the age of 40. Schizophrenia in children under the age of 12 is rare.

The typical age of onset for schizophrenia symptoms is in the 20s, though people may develop other symptoms as early as 9 years before diagnosis. A 2020 study found the average age of onset for schizophrenia to be between 13.78 and 29.28 years.

Early onset of schizophrenia occurs before a person’s 20s. It is very uncommon for children under the age of 12 to have symptoms of schizophrenia. Doctors call this very early-onset schizophrenia.

Early-onset schizophrenia occurs in teenagers ages 13–18. It is more common than childhood schizophrenia, but it is still fairly uncommon.

Numerous studies on early-onset schizophrenia have reached mixed conclusions about the course of the condition. However, more recent research suggests that symptoms tend to be more severe when they appear early in life.

A 2017 systematic review and meta-analysis correlated early-onset schizophrenia with:

  • more hospitalizations
  • more relapses
  • more negative symptoms
  • less social functioning
  • less employment functioning
  • less overall functioning

A 2014 study suggests that exposure to more environmental risk factors for schizophrenia in people with a genetic predisposition to the disease might cause symptoms to appear earlier in life.

As much as 20% of people with schizophrenia develop symptoms after the age of 40, usually between the ages of 40 and 60. This is late-onset schizophrenia.

There is ongoing debate about whether this is the same disease, with the same risk factors, as schizophrenia that occurs prior to midlife or early-onset schizophrenia. A 2014 study highlights research suggesting that later onset of schizophrenia could be a unique disease subtype.

Very late-onset schizophrenia appears for the first time after age 60.

A 2018 study emphasizes the link between late-onset schizophrenia and other neurological disorders, such as dementia. People with late-onset schizophrenia are three times more likely to have dementia than their same-age peers.

Therefore, late-onset schizophrenia could be a risk factor for dementia.

Late-onset schizophrenia could also be a prodrome of other diseases. For example, it could be an early manifestation of certain types of dementia.

Schizophrenia affects a person’s ability to think clearly and to draw accurate conclusions about the world around them. The symptoms include:

  • hallucinations, or perceiving things others do not
  • delusions, or thinking things that appear to be untrue
  • changes in the expression of emotions
  • cognitive issues
  • difficulties in relationships with others
  • atypical or socially unacceptable behaviors

Some, but not all, people who develop schizophrenia have other mental health symptoms before schizophrenia symptoms appear. These may include:

Learn more about the stages of schizophrenia here.

Like other mental illnesses, schizophrenia has complex biological, social, psychological, and developmental roots.

Genetics play an important role. A 2021 article reports that if both parents have schizophrenia, a person has a 40% chance of developing the condition. When one identical twin has schizophrenia, their twin also has the condition in 46% of cases.

While a person cannot change their genes and this data points to the important role of genetics, it also shows that genes are not the only — or even necessarily, the most important — factor.

Recent research increasingly treats schizophrenia as a developmental condition, which means that factors that occur during development can increase the odds of schizophrenia, especially in people who are already at a genetically high risk.

A 2014 study found a correlation between environmental risk factors in people at a higher genetic risk for schizophrenia and the later development of schizophrenia symptoms.

Some early developmental risk factors include:

  • inadequate prenatal nutrition
  • infection in the gestational parent during pregnancy
  • oxygen deprivation at birth
  • trauma
  • cannabis use

Minimizing these risk factors may reduce the risk of developing schizophrenia. Quality prenatal care, access to healthy food and support during pregnancy, and support to ensure people only become pregnant when they are ready to care for themselves and the pregnancy may all reduce the risk of schizophrenia.

Similarly, measures that reduce the risk of childhood trauma, such as by reducing childhood poverty and supporting at-risk families, may help.

The correlation between cannabis use and schizophrenia is not clear, but people with a family history of the condition may wish to avoid cannabis, even medical cannabis.

Schizophrenia is a chronic illness that usually lasts a lifetime, though treatment can manage symptoms. Some people find full relief with treatment, while others may relapse or have to try several different treatments before getting any relief.

While the average age of schizophrenia onset can help with deciding how likely it is that a person’s symptoms stem from schizophrenia, people of any age can have schizophrenia.

Age is not a good predictor of schizophrenia risk, since many factors influence individual schizophrenia risk. There is no age at which the risk of developing schizophrenia disappears.

Many people with schizophrenia do not realize they have symptoms. This is because disconnection from reality and false beliefs are hallmarks of schizophrenia. Helping a person with schizophrenia seek treatment may be difficult.

People who think they might have schizophrenia, or whose loved ones have expressed concern, should contact a mental health professional or doctor for guidance.