Insistence on sameness, repetitive negative thinking and mental health in autistic and non-autistic adults
Authors: Cooper Kate , Russell Ailsa 
Published: September 2024

Autistic people experience high rates of mental health problems. A tendency towards behavioural repetition in autistic individuals could contribute to repetitive negative thinking, which is a transdiagnostic risk factor for mental health problems. Our research aimed to add to the literature by using transdiagnostic measures of both mental health symptoms and repetitive negative thinking. We explored the relationships between insistence on sameness and depression-anxiety, via the mediating role of repetitive negative thinking, operationalised as rumination and obsessing. Three groups of adults were recruited; autistic clinical cohort participants ( n = 67); autistic community participants ( n = 54) and non-autistic community participants ( n = 66). All participants completed measures of Insistence on sameness; Anxiety and Depression; Obsessing; Rumination. Autistic community participants had significantly higher insistence on sameness, rumination and obsessing scores than non-autistic community participants. The mediation analysis found support for the hypothesis that the relationship between insistence on sameness and depression-anxiety would be mediated by rumination and obsessing in all participants. The higher rates of repetitive negative thinking found in autistic individuals may contribute to elevated rates of mental health problems in this group. Mental health assessments and interventions for autistic people should consider transdiagnostic factors including multiple forms of repetitive negative cognition and behaviour. Lay abstract Autistic people are more likely to have mental health problems than non-autistic people. We know that having repetitive and negative thoughts can contribute to multiple mental health problems such as depression and obsessive-compulsive disorder. Autistic people often do the same behaviours repetitively, and they may also have more repetitive thinking styles. This could contribute to higher rates of mental health problems in autistic people. In this research, we wanted to find out if higher rates of repetitive behaviours contributed to depression and anxiety, and whether this relationship was because of repetitive negative thinking. We asked three groups of autistic adults to take part in the research. Sixty-seven autistic clinical participants were recruited from clinical settings and had moderate depression. Fifty-four autistic community participants and 66 non-autistic community participants were recruited from community settings. All participants completed measures of repetitive behaviours; a measure of anxiety and depression; and two measures of repetitive negative thinking (ruminating and obsessing). Autistic community participants had significantly higher repetitive behaviours, rumination and obsessing scores than non-autistic community participants. We found that higher rates of repetitive behaviours contributed to more repetitive thinking (obsessing and ruminating), which contributed to higher rates of depression and anxiety. The higher rates of repetitive negative thinking found in autistic individuals may contribute to higher rates of mental health problems in this group. Mental health assessments and interventions for autistic people should therefore consider the role of multiple forms of repetitive negative cognition and behaviour, which cut across diagnostic categories such as anxiety, depression and obsessive-compulsive disorder. These should be considered when aiming to understand why individuals develop mental health conditions and why these conditions persist.