Danish study finds link between ASD and suicidal behaviour

A study of the Danish population aged 10 years and over has found those diagnosed with autism spectrum disorder (ASD) were over three times more likely to attempt suicide and to die by suicide.

Published in JAMA Network Open, the study analysed whether people with ASD had higher rates of suicide attempt and suicide when compared to people with no ASD using national register data from 1995-2016 and risk factors of suicidal behaviours in those with ASD.

The results showed the incidence rates of suicide attempt were 266.8 per 100,000 people diagnosed with ASD and 63.4 for the rest of the population.

“Lack of social integration, unemployment, and psychiatric disorders are common in adults with ASD, the same factors are traditionally associated with suicidal behavior,” said lead author Dr Kairi Kolves from the Australian Institute for Suicide Research and Prevention.

“But there is scant evidence showing a link between ASD and suicidality from large-scale studies. Ours is the first to show an elevated rate of suicide attempt and suicide in persons diagnosed with ASD, after adjusting for sex, age and time period, in a nationwide cohort study.”

“Factors, which have been identified as protective against suicide attempt in the general population, such as older age and higher education were not found to have this effect in those with ASD, and some factors such as being married or cohabiting and employed were linked to less impact among those with ASD.”

The majority of factors associated with suicide in the general population such as being male or not in a relationship, were not associated with suicide among those with ASD.

Psychiatric comorbidity was found to be a major risk factor with over 90% of those with ASD, who attempted or died by suicide, having another comorbid condition, with anxiety and affective disorders being most common.

Dr Kolves said higher levels of cognitive functioning and education could imply a wider exposure to different risk factors.

“But also the self-realisation of rather limited social and problem-solving skills may increase self-imposed pressure to cope with and alter expectations of success.

“These factors are crucial for assessing suicide risk by practitioners working with people with ASD, particularly for those with other psychiatric comorbidities.”

She said the reason for linking ASD to suicidality, particularly in adults, might be a combination of social isolation and poor access to care.

While it is possible that an inability to establish and retain social and intimate relationships may severely affect adult women with ASD, they might also be diagnosed and treated later in the course of the disorder by being able to camouflage their autistic traits.

“This might explain their higher rates of suicidal behavior (4.6 times higher than males) which is supported by findings from Swedish linkage studies where higher risk of suicidal behavior was noted for females with ASD compared to males.

“A number of risk factors are different from those in the general population which suggests the need for tailored suicide prevention activities such as more robust screening procedures, early interventions to improve social skills of children and adolescents with ASD and the expanding of access to care.”