Examination of the Potential Moderating Role of Psychological Wellbeing in the Relationship Between Depression and Thoughts of Self-harm in Autistic Adolescents and Adults: A Two-year Longitudinal Study

Purpose. Autistic people have a significantly increased risk of death by suicide relative to the general population. In non-autistic samples, psychological wellbeing has been shown to moderate the relationship between depression and suicidal ideation, but this model has not been tested in an autistic sample. In this longitudinal study we examined (a) the potential role for psychological wellbeing to moderate the relationship between depressive symptoms and thoughts of self-harm (used as a proxy for suicidal ideation) and (b) the contribution of autistic traits to thoughts of self-harm. Methods. Participants were 209 autistic adolescents and adults aged 15 to 80 years (Mage = 34.20, SD = 15.38 years). Results. At both baseline and 2-year follow-up, 35% of participants reported recent thoughts of self-harm. Wellbeing was associated with autistic traits (r = –0.350 to –0.404) and depression (r = –0.480 to –0.759). Thoughts of self-harm were positively associated with autistic traits and depression (r = 0.242 to 0.659), and negatively associated with wellbeing (r = –0.287 to –0.609). Controlling for baseline thoughts of self-harm, depression (β = 0.254, p = .001) and autistic traits (β = 0.162, p = .007) significantly predicted thoughts of self-harm at 2-year follow-up. Conclusion. Despite a lack of support for the hypothesis that wellbeing would moderate the relationship between depression and thoughts of self-harm, correlational data demonstrated significant associations between wellbeing and both depression and thoughts of self-harm. Future research considering psychological wellbeing as a potential protective factor for suicidality in autistic people is warranted.