The greatest risk factor for developing schizophrenia is having a first-degree relative with the disease (risk is 6.5%); more than 40% of identical twins of those with schizophrenia are also affected. If one parent is affected the risk is about 13% and if both are affected the risk is nearly 50%. However, the DSM-5 indicates that most people with schizophrenia have no family history of psychosis. Results of candidate gene studies of schizophrenia have generally failed to find consistent associations, and the genetic loci identified by genome-wide association studies explain only a small fraction of the variation in the disease.Many genes are known to be involved in schizophrenia, each with small effect and unknown transmission and expression. The summation of these effect sizes into a polygenic risk score can explain at least 7% of the variability in liability for schizophrenia. Around 5% of cases of schizophrenia are understood to be at least partially attributable to rare copy number variations (CNVs); these structural variations are associated with known genomic disorders involving deletions at 22q11.2 (DiGeorge syndrome) and 17q12 (17q12 microdeletion syndrome), duplications at 16p11.2 (most frequently found) and deletions at 15q11.2 (Burnside–Butler syndrome). Some of these CNVs increase the risk of developing schizophrenia by as much as 20-fold, and are frequently comorbid with autism and intellectual disabilities.The genes CRHR1 and CRHBP are associated with the severity of suicidal behavior. These genes code for stress response proteins needed in the control of the HPA axis, and their interaction can affect this axis.
The new name, also interpreted as "integration disorder", was inspired by the biopsychosocial model. A similar change was made in South Korea in 2012 to attunement disorder.In the United States, the annual cost of schizophrenia – including direct costs (outpatient, inpatient, drugs, and long-term care) and non-healthcare costs (law enforcement, reduced workplace productivity, and unemployment) – was estimated at $62.7 billion for the year 2002. In the UK the cost in 2016 was put at £11.8 billion per year with a third of that figure directly attributable to the cost of hospital, social care and treatment. Cultural depictions
The book A Beautiful Mind chronicled the life of John Forbes Nash who had been diagnosed with schizophrenia and won the Nobel Memorial Prize in Economic Sciences. The book was made into a film with the same name; an earlier documentary film was A Brilliant Madness. In 1964 a case study of three males diagnosed with schizophrenia who each had the delusional belief that they were Jesus Christ was published as The Three Christs of Ypsilanti; a film with the title Three Christs was released in 2020.Media coverage reinforces public perception of an association between schizophrenia and violence; in film, people with schizophrenia are highly likely to be portrayed as a danger to others. In the UK guidelines for reporting conditions and award campaigns have shown a reduction in negative reporting since 2013.