Autism and Premature Death: The Connection

A recent government survey of parents suggests that 1 in 45 children, ages 3 through 17, have been diagnosed with autism spectrum disorder (ASD). And now, a registry study conducted at Karolinska Institutet and published in The British Journal of Psychiatry shows that the risk of premature death is about 2.5 times higher for people with ASD than for the rest of the population.

ASD comprises neurodevelopmental conditions that affect social interaction and communication, as well as behavioral flexibility. Researchers at Karolinska Institutet have now been able to demonstrate that the risk of premature death for the first group applies to both women and men, many different causes of death, and individuals with and without concomitant intellectual disability.

“We can now see that the ASD group has a higher mortality risk in almost all cause-of-death categories, which means that knowledge of autism is essential for all medical specialties,” says Professor Sven Bölte, head of the Centre of Neurodevelopmental Disorders at Karolinska Institutet (KIND).

The first series of analyses in the study concerned overall mortality, regardless of cause of death. During the follow-up period, 2.6 percent of the ASD group had died, compared to almost 1 per cent of the controls.

“We see an association between ASD and an increased risk of premature death,” says Tatja Hirvikoski, researcher at Karolinska Institutet and head of research and development for the Stockholm County Council’s Habilitation Services. “A particularly at-risk group is women with ASD and intellectual disability.”

The group of people with ASD but no intellectual disability, however, had a higher risk of death from one specific cause: suicide.

“There’s a very clear connection between ASD without intellectual disability and a raised suicide risk,” says Dr Hirvikoski. “Clinical guidelines for suicidal patients must be followed when dealing with people with ASD.”

Data for the participants with ASD was extracted from the Swedish patient registry, while that for the control group came from the population registry; both sets were then linked to the causes of death registry. The study included over 27,000 individuals with ASD, of whom 6,400 also had an intellectual disability, and some 2.5 million individuals from the general population. The individuals in the comparison group were matched to those in the ASD group as regards county of residence, sex and age.

This large registry study – the largest of its kind – was a joint project between three departments at Karolinska Institutet: The Department of Clinical Neuroscience, the Department of Women’s and Children’s Health and the Department of Medical Epidemiology and Biostatistics.