People suffering from mental disorders such as schizophrenia have a higher rate of left-handedness than the general population, according to a new study CBS News reported.
According to CBS News, about 10 percent of people are left-handed. However, the prevalence of left-handedness was 40 percent in patients diagnosed with psychotic disorders such as schizophrenia, according to the study.
"Our results show a strikingly higher prevalence of left-handedness among patients presenting with psychotic disorders such as schizophrenia and schizoaffective disorder, compared to patients presenting for mood symptoms such as depression or bipolar disorder," the researchers wrote.
Researchers surveyed only 107 people who were being treated for psychological problems.
According to Science 2.0, scientists and psychologists have long been interested in handedness "because the brain develops asymmetrically and some cognitive processes develop from the left or right side."
Researchers also found left-handedness was prevalent in 11 percent of those diagnosed with mood disorders such as depression and bipolar disorder, which is about the same rate in the general population.
Since hand dominance is a convenient measure, it's been a focus for decades, with some research finding a great prevalence of psychosis in left-handed people. A recent meta-analysis of over 40 studies concluded that left-handedness is more prevalent in psychiatric illness, according to the report.
The authors also discuss additional factors that might be tied to the connection between schizophrenia and left-handedness such the variation of brain lateralization, scholastic achievement or race.
"Our own data showed that whites with psychotic illness were more likely to be left-handed than black patients. Even after controlling for this, however, a large difference between psychotic and mood disorder patients remained," researchers wrote.
Scientists say there is still much about the differences between righties and lefties they do not understand.
The study, "Left-Handedness Among a Community Sample of Psychiatric Outpatients Suffering From Mood and Psychotic Disorders," was published in the journal, SAGE Open.
