Home > Mental health > News Updated 04 November 2013 Lefties more likely to have psychotic disorders American researchers say 40% of patients being treated for schizophrenia or other mental disorders are left-handed. 1 iStock Related Genes determine if you're right- or left-handed Genes determine if you're right- or left-handed Ask CyberShrink » Talk Heart to heart forum » 13 hidden signs of stress Regenerative medicine: replacing brain cells lost from stroke Being left-handed has been linked to many mental disorders, but Yale researcher Jadon Webb and his colleagues have found that among those with mental illnesses, people with psychotic disorders like schizophrenia are much more likely to be left-handed than those with mood disorders like depression or bipolar syndrome.The new study is published in the October-December 2013 issue of the journal SAGE Open.About 10% of the US population is left-handed. When comparing all patients with mental disorders, the research team found that 11% of those diagnosed with mood disorders such as depression and bipolar disorder are left-handed, which is similar to the rate in the general population. False beliefsBut according to Webb, a child and adolescent psychiatry fellow at the Yale Child Study Centre with a particular interest in biomarkers of psychosis, "a striking 40% of those with schizophrenia or schizo-affective disorder are left-handed.""In general, people with psychosis are those who have lost touch with reality in some way, through hallucinations, delusions, or false beliefs and it is notable that this symptom constellation seems to correlate with being left-handed," said Webb. "Finding biomarkers such as this can hopefully enable us to identify and differentiate mental disorders earlier and perhaps one day tailor-made treatment in more effective ways."Left-handedness frequencyWebb and his colleagues studied 107 individuals from a public outpatient psychiatric clinic seeking treatment in an urban, low-income community.The research team determined the frequency of left-handedness within the group of patients identified with different types of mental disorders.The study showed that white patients 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," said Webb.Mental healthWhat sets this study apart from other research is the simplicity of the questionnaire and analysis, said Webb.Patients who were attending their usual check-ups at the mental health facility were simply asked "What hand do you write with?""This told us much of what we needed to know in a very simple, practical way," said Webb."Doing a simple analysis meant that there wasn’t any obstacles and we had a very high participation rate of 97%”. “Patients dealing with serious symptoms of psychosis might have had a harder time participating in a more complicated set of questions or tests."By keeping the survey simple, we were able to get an accurate snapshot of a hard-to-study subgroup of mentally ill people those who are often poverty-stricken with very poor family and community support." EurekAlert NEXT ON HEALTH24X When head injuries make life hard, suicide risk goes up 2018-08-28 11:00 More: Mental healthNews advertisement Read Health24’s Comments Policy Comment on this story 1 comment Comments have been closed for this article. Logout Comment 0 characters remaining Share on Facebook Loading comments... Other news Lifestyle Lung scans of smokers with COPD can reveal heart disease Lifestyle Here are the unexpected places where germs live Diet and nutrition For cod's sake, eat more seafood if you can Parenting Single father: 'I speak to my daughter about sex' Medical Drinking coffee might help with this skin condition Medical Exercising with allergies – what you should know From our sponsors Dementia and Incontinence: what you need to know Tell-tale signs you need a mattress upgrade Keen to win a R2 000 voucher? Good health begins in your gastrointestinal tract Live healthier Gut health » Can't lose weight? Blame it on your gut Our nutrition experts weigh in on why gut health is such an important factor in weight loss, on World Obesity Day. Sleep better » Yes, there is such a thing as too much sleep A new study confirms that too little sleep can impair your brain, but interestingly, too much sleep is also a problem.