Left-handedness linked to autism, schizophrenia in major neurological study

Left-handedness and certain neurological disorders could be linked, according to a recent study that analyzed data from over 200,000 individuals. While approximately 10% of the global population is left-handed, individuals with conditions like autism are 3.5 times more likely to exhibit this trait.

The study, published in the journal Psychological Bulletin, revealed that left- and mixed-handedness are more prevalent in individuals diagnosed with schizophrenia, autism, and intellectual disabilities. Mixed-handedness differs from ambidexterity, as it involves using the left hand for some tasks and the right hand for others.

Lead author Dr. Julian Packheiser from Ruhr University Bochum in Germany emphasized that while atypical handedness is associated with certain psychiatric and psychological conditions affecting language systems, it does not imply causation. Not all neurological conditions showed a correlation with dominant hand preference, as depression and dyscalculia exhibited no significant differences.

Neurologist Dr. Earnest Lee Murray explained that individuals with atypical handedness may have a more evenly distributed language system in their brains, as opposed to a dominant side for speech and logical processing. The study also highlighted a potential connection between left- and mixed-handedness and long-term linguistic issues like stuttering and dyslexia.

The researchers noted that disorders with early onset symptoms were more likely to be associated with atypical handedness. Thumb-sucking patterns in the womb at 10 weeks gestation were linked to the preferred hand later in life, suggesting that handedness is determined at an early age.

Despite the findings, experts cautioned against drawing definitive conclusions, emphasizing the need for further research to understand the relationship between handedness and mental health. While the study provides valuable insights, it is crucial to interpret the results with caution to avoid unnecessary alarm or stigma.

Overall, the study sheds light on the potential connection between handedness and neurological disorders, offering valuable insights for future research and potential implications for neurorehabilitation strategies. As our understanding of brain organization and development continues to evolve, further studies in this area could provide valuable insights into the complexities of the human brain.