Schizophrenia risk factors

Schizophrenia affects 24 million people or 1 in 300 people worldwide, with a lifetime prevalence of approximately 1%. [Source: World Health Organisation, 2022]

Despite relatively low prevalence, schizophrenia is associated with significant disability as demonstrated in the Global Burden of Disease Study (GBD) whereby acute psychosis was found to have the highest disability weight of any cause. In 2019, the study found schizophrenia to be the 3rd leading cause of disability (measured as disability-adjusted life years) among the twelve mental disorders included in GBD.

Schizophrenia costs the Australian community approximately $2.6 billion per annum in both direct health costs and loss of productivity. [Source: Schizophrenia Research Institute 2013]

There is a strong contribution for genetic factors in determining risk for schizophrenia. Twin and family studies have historically reported significant heritability for schizophrenia, often summarized as 81%.

Large collaborative international studies have revealed that many common genetic variants, which are spread across the genome, can each contribute small increased risks. [Source: Schizophrenia Working Group of the Psychiatric Genomics Consortium 2014]

Many non-genetic and environmental risk factors have been implicated in schizophrenia risk, including season of birth, urbanicity, migrant status, paternal age, birth complications, infections, drug use, childhood adversity and traumatic life events.

QBI researchers have pioneered the study of developmental Vitamin D deficiency as a risk factor in schizophrenia.