The different aspects of the human brain and the dominance of the hand have been of interest to researchers for a long time. A new study, published in the October 2013 issue of the magazine SAGE Open, suggests that among people with mental illnesses, left-handed people are more likely to suffer from psychotic disorders like schizophrenia, rather than mood disorders.
“The human brain develops asymmetrically, so that certain cognitive processes mainly occur on the left or right side. It has been suggested that variations in this laterality contribute to certain forms of mental illness, such as schizophrenia,” the authors write. of the study.
US researchers examined 107 patients at a public psychiatric clinic to determine the frequency of left-handed people in certain groups treated for different mental disorders. They found that 11% of people with bipolar or mood disorders like depression were left-handed, which approximates the percentage of the general population. This figure rises to 40% at people with schizophrenia or schizoaffective disorders.
Scientists took into account different factors that could influence these results, such as variation in brain lateralization, academic achievement or ethnicity. But “despite taking these variables into account, a big difference between psychotic patients and those with mood disorders remains intact,” they say, cited by the site Medical Xpress.
