<P> As defined by experts with a biomedical background, a mental disorder is "a clinically significant behavioral or psychological syndrome or psychological pattern that occurs in an individual and that is associated with present disability or with a significantly increased risk of suffering, death, pain, disability, or an important loss of freedom ." The causes of mental disorders are generally complex and vary depending on the particular disorder and the individual . </P> <P> Although the causes of most mental disorders are unknown, it has been found that different biological, psychological, and environmental factors can all contribute to the development or progression of mental disorders . Most mental disorders are a result of a combination of several different factors rather than just a single factor . </P> <P> Risk factors for mental illness include genetic inheritance, such as parents having depression, repeating generational patterns, and dispositions like personality . Correlations of mental disorders with drug use include cannabis, alcohol and caffeine . </P>

The most likely theories for the cause of mental disorders involve