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Age at onset

How is age at illness onset important to people with schizophrenia? 

Differences are observed in the age at onset of psychotic symptoms, which may be influenced by genetic or environmental risk factors, or sex. Understanding the factors that impact on age at the onset of symptoms could lead to better understanding of the risk factors for the disorder and earlier and improved intervention strategies.

What is the evidence relating to age of illness onset?

Moderate to high quality evidence finds the incidence (i.e. new cases) of schizophrenia is higher in males up until around 40 years of age, then higher in females after around 50 years of age.

Substance use, in particular cannabis, is associated with an earlier age at onset of psychosis, with no effect of tobacco use. There was also a small effect of an earlier age at onset in people with a family history of psychosis.

Moderate quality evidence finds small associations between an earlier age at onset and more hospitalisations, more negative, but not positive symptoms, more relapses, poorer overall functioning and poorer overall clinical outcomes (in males only).

Moderate to low quality evidence finds an earlier age at first contact with services in males compared to females in Western countries (small effect).

 

February 2019

Page last updated: 2:10  6 February 2019

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