Researchers from the Medical Center at the University of Utrecht concluded that left-handed people are more likely to develop various mental illnesses. They often manifest in the form of psychoses, and first of all, they are schizophrenia or schizoaffective disorders, and not mood disorders, such as depression or bipolar disorder, which confirms the previously discovered genetic relationship between schizophrenia and left-handedness.
Dutch scientists decided to calculate how many of the victims of various mental disorders are right-handed and left-handed. It turned out that lefties make up 11% among patients who suffer from mood disorders, and as much as 40% among patients with schizophrenia. Comparing the general ratio of right-handed and left-handed people all over the world, the conclusion suggests itself that the latter more often suffer from major psychoses.
According to statistics, the number of left-handed people on the planet is 11%. Thus, their percentage among victims of mood disorders will not raise questions for anyone, which cannot be said about the incidence of more serious mental illnesses. Researchers studied patients from state psychiatric clinics that are not located in the most prestigious and wealthy areas. It turned out that left-handedness to a greater extent increases the risk of severe mental disorders, in contrast to skin color, level of material wealth and other factors. True, the reason for this tendency of left-handed people to diseases of the psyche could not be established.
By the way, earlier, scientists from the Netherlands also found that left-handed women were more likely than right-handed women to have breast cancer before menopause. But there is at least a version that explains this imbalance. According to scientists, the left-handedness itself is laid in the mother’s womb due to exposure to the fetus too high levels of sex hormones. Which subsequently can lead to changes in the soft tissues of the breast.