Suicidality in Adults with Autism Spectrum Disorder: The Role of Depression and Alexithymia

Background: Individuals with autism spectrum disorder (ASD) have a higher risk of depression and suicidality than individuals without ASD. Alexithymia, a personality construct characterized by a lack of emotional awareness, that is highly linked to depression, is also more prevalent among people with ASD than in the general population. Few studies have so far examined the increased risk of suicidality in people with ASD and none have looked into how alexithymia could be a significant risk factor for suicidality in ASD.

Objectives: The aim of the present study is to explore more closely the relationship between alexithymia, depression, and suicidality in ASD. It is hypothesized that there are higher rates of depression, suicidality, and alexithymia in people with ASD compared to neurotypical adults. Because the risk of suicidality can be explained by high levels of depression and alexithymia in the general population, this is also hypothesized for the group of people with ASD.

Methods: In the present study, 53 adults diagnosed with ASD and a control group of 132 adults without ASD were compared on their self-reported scores on autistic traits (AQ-short), depression (CES-D), suicidality (SBQ-R), and alexithymia (TAS-20). Participants were aged between 18 and 60 years. The ASD group was significantly older (M = 33.75; SD = 11.02) than the control group (M = 29.08; SD = 8.74), t(183) = -3.04, p < .01 and there were significantly more men than women in the ASD group (21 men, 31 women, 1 other) than in the control group (31 men, 101 women), χ²(2) = 7.72, p < .05.

Results: The results revealed that the ASD group had significantly higher levels of autistic traits [F(1, 181) = 394.61, p < .001, ɳ_p² = .69], depression [F(1, 181) = 51.86, p < .001, ɳ_p² = .22], suicidality [F(1, 181) = 71.51, p < .001, ɳ_p² = .28], and alexithymia [F(1,181) = 143.44, p < .001, ɳ_p² = .44] than the control group. A hierarchical linear regression analysis including age, gender, autistic traits, depressive symptomatology, and alexithymia also revealed that the severity of autistic traits and depressive symptomatology were significant predictors of suicidality (autistic traits: β = 1.24, p <.001; depression: β = 1.30, p <.001). Furthermore, alexithymia played a moderating role in the relation between autistic traits and suicidality: a significant relation was found between autistic traits and suicidality on participants with high levels of alexithymia [b = 1.61, SE = 0.31, p < .001], but autistic traits were not related to suicidality on participants with low levels of alexithymia [b = -0.54, SE = .45, p = .24].

Conclusions: The present results show that individuals with ASD are vulnerable to suicidal ideation and that the severity of autistic traits, depression, and alexithymia are important factors in the occurrence of suicidal ideation in ASD. Because of the high risk of suicidality in ASD, interventions that take into consideration depression, and particularly alexithymia, could potentially benefit people with ASD.