Understanding the interplay of autistic traits, depression and suicidal ideation in adolescents with major depressive disorder

Adolescents with autistic traits (ATs) experience higher rates of depression and suicidal behavior. This study aims to investigate the relationship between ATs, depressive symptoms, and suicidal ideation (SI) in adolescents with major depressive disorder (MDD). Seventy adolescents, aged 11-18 and diagnosed with MDD, were included. Participants were evaluated with the ColumbiaSuicide Severity Rating Scale (CSSR-S), Beck Depression Inventory (BDI), and ATs using the Autism Spectrum Quotient (AQ). Three groups were compared: those without suicidal thoughts (ST-), suicidal thoughts (ST+), and suicide attempts (SA). While the SA group scored significantly higher on the C-SSRS, BDI, and AQ compared to the ST- group; ST + and SA groups didn't differ. The mediating role of depression was investigated via a Bayesian mediator analysis for CSSR-S subheaders of current and lifetime suicidal ideation and ideation intensity. The effect of BDI scores on current suicidal ideation was β = 0.08 (CI[0.04-0.13]), which was consistent with lifetime suicidal ideation with the same effect size β = 0.08 (CI[0.03-0.13]). For current suicidal ideation and its intensity, autistic traits had an indirect effect through BDI scores, with an indirect mean of 0.050 (CI[0.02-0.10]). For lifetime suicidal ideation, autistic traits exhibited both a direct (β = 0.09, (CI[0.01-0.16]) and an indirect effect through depression scores, with a mean of 0.052 (CI [0.015-0.102]). The complex interplay between ATs, depressive symptoms, and SI in adolescents diagnosed with MDD suggests that interventions targeting autistic traits may be a useful component of comprehensive mental health strategies for adolescents with MDD and elevated suicidal risk.