New York, Oct 15 : Some restrictive and repetitive behaviours may help reduce anxiety for autistic individuals, finds a study that sheds new light on the relationship between autism traits and mental health in middle childhood. The paper, published in the journal Autism, finds that changes in core autism characteristics are related to whether children develop additional mental health challenges during their elementary school years. A key finding was that a reduction in restrictive and repetitive behaviours during elementary school was linked to the emergence of mental health challenges, lending support to the idea that these behaviours may benefit autistic individuals. An increase in social-communication difficulties during this time was also linked to anxiety and other mental health challenges. The study included 75 autistic children age 6 to 11, including 15 girls. About a fifth (21 per cent) of the youth had more severe social-communication difficulties, as well as an increase in anxiety, ADHD and behavioural challenges. In contrast, nearly 23 per cent had decreased restricted and repetitive behaviours but higher anxiety levels by age 11. Nearly all -- 94 per cent -- met the criteria for an anxiety disorder. About a third of the participants had both decreasing restricted and repetitive behaviours and increased social-communication difficulties. 'We were pleased to see that our results confirmed what has been suspected by other autism researchers and clinicians as well as autistic individuals, that some forms of restricted and repetitive behaviours can potentially help to self-soothe,' said David Amaral, Professor at the varsity's Department of Psychiatry and Behavioral Sciences The team noted that the findings question the wisdom of therapies that try to eliminate these behaviours. 'In light of this, when thinking about interventions, it might be that trying to eliminate repetitive behaviours without providing alternative self-soothing tools is not the ideal way to go,' said lead author Einat Waizbard-Bartov, a doctoral researcher in developmental psychology at the University of California-Davis. The study is the first, to the authors' knowledge, to demonstrate an association between mental health challenges and increases in the severity of social-communication difficulties for autistic children. 'This occurred in children who showed decreases in core autism traits during early childhood and whose cognitive functioning was in the typical range. We don't currently understand why this happened. One possibility is that due to their relatively high cognitive ability, they became aware of their social challenges, and this may have contributed to increasing anxiety,' Amaral explained. 'It's definitely an area where we need more research.' /IANS