There are no proven single causes of Schizophrenia. Like all mental diseases it is not one hundred percent understood. There are many factor that can lead up or cause this mental disorder which scientists are very unaware of. It is not caused by bad diet or horrible upbringings. Stress can trigger and worsen many of the symptoms but is not the cause of the disorder. Schizophrenia is a disorder of the brain and it is likely there are a mix of factors that may cause it. Some of those involve a chemical disorder in the brain causing a lack of understanding and interacting appropriately, genetic makeup, and a defect in how the brain develops ones personality. Scientists strongly believe that there are really two factors that play apart in creating this disorder. Genes and the environment. Scientists believe that since genes are passed down there are more than one that create this, rather than one singular gene. If your mother, father, sister, brother, etc., have schizophrenia your chances of getting it genetically passed down are much higher.