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 More in Mental health Troubled childhood may boost bipolar risk 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 Sex US STIs hit all-time high in 2015 Medical Human right-handedness might go back almost 2 million years Mental health Troubled childhood may boost bipolar risk Diet and nutrition Our genes may soon advise our food and lifestyle choices Lifestyle Which skin products are better, ‘medical grade’ or ‘over-the-counter’? Medical Don't believe these asthma myths From our sponsors Keep an eye on your vision Which skin products are better, ‘medical grade’ or ‘over-the-counter’? Win 1 of 6 R5000 cash prizes Win Skin Renewal voucher Live healthier Exercise benefits for seniors » Working out in the concrete jungle Even a little exercise may help prevent dementia Here’s an unexpected way to boost your memory: running Seniors who exercise recover more quickly from injury or illness When sedentary older adults got into an exercise routine, it curbed their risk of suffering a disabling injury or illness and helped them recover if anything did happen to them. No relief for MS » Drug shows promise against MS in mouse study Vitamin D may slow multiple sclerosis Obesity in girls tied to higher MS risk Exercise may not lower women's risk of MS A Harvard study showed no evidence to support the idea that exercise lowers the risk of multiple sclerosis.