Recent findings highlight a staggering rate of suicidal thoughts among adults with Asperger’s syndrome.

“Depression is an important potential risk factor for suicidal thoughts in people with this condition,” said psychologist and study author Dr. Sarah Cassidy, a researcher at the Autism Research Centre (ARC) at the University of Cambridge, U.K.

The research team states in the journal Lancet Psychiatry that Asperger’s syndrome in adulthood is often linked to depression. So they set out to explore the extent of suicidal thoughts and plans in this group.

Survey data was used on 256 men and 118 women who were diagnosed by a clinician with Asperger’s syndrome between 2004 and 2013 in England. Any depression, suicidal thoughts, or plans were recorded on a self-report questionnaire, along with self-reported autistic traits and empathy.

Two-thirds (66 percent) of the respondents reported suicidal thoughts, 35 percent reported plans or attempts at suicide, and 31 percent reported depression.

Compared with the general population, adults with Asperger’s syndrome were nearly 10 times more likely to report suicidal thoughts. They were also significantly more likely to have these thoughts than people with one, two, or more medical illnesses, or people with a psychotic illness.

Those with Asperger’s syndrome and depression were four times more likely to report suicidal thoughts and suicide plans or attempts than those with Asperger’s syndrome but without depression. Having a higher level of self-reported autistic traits was also linked to a greater risk.

In their paper, the team says it is “puzzling” that more people in this sample reported lifetime experience of suicidal thoughts (66 percent) than were depressed (31 percent). One explanation could be under-reporting of depression, perhaps because of the difficulties verbally describing subjective emotional experience often seen in Asperger’s.

“Our findings lend support to depression as an important potential risk factor for suicidality in adults with this condition,” write the authors.

“Because adults with Asperger’s syndrome often have many risk factors for secondary depression, our findings emphasize the need for appropriate service planning to reduce risk in this clinical group.”

Patients’ depression and risk of suicide are preventable with the appropriate support, the authors add.

Co-author and ARC Director Dr. Simon Baron-Cohen said, “Adults with Asperger’s syndrome often suffer with secondary depression due to social isolation, loneliness, social exclusion, lack of community services, underachievement, and unemployment.

“This study should be a wake-up call for the urgent need for high quality services, to prevent the tragic waste of even a single life. ”

More detailed studies are needed into the triggers and experience of suicidal thoughts, the risk-promoting and protective factors for suicide plans and attempts in adults with Asperger’s syndrome (such as age at diagnosis), and family history of suicide and aggression, he adds.

Commenting on the study, Michele Raja, M.D., of the University “La Sapienza” in Rome, Italy, said the findings “should encourage clinicians to be vigilant in assessment of the risk of suicide in these patients.”

Raja, an expert on suicide and psychiatric illness, said suicide has been neglected in research on autism and Asperger’s syndrome, perhaps due to the low rate of suicidal behavior in children and young people, and the underdiagnosis of the conditions in adults.

He said adults with Asperger’s syndrome or autism tend to only be seen by mental health professionals if they have severe mood changes or psychotic symptoms in addition to their Asperger’s syndrome or autism.

This means they may be given an incorrect diagnosis such as schizophrenia, and suicidal behavior in adults with Asperger’s syndrome or autism is often not linked to the unrecognized condition itself.

Raja also said this study included only patients who were not diagnosed with Asperger’s syndrome until adulthood. It may be that adults with Asperger’s syndrome who are correctly diagnosed and treated as children have a lower risk of suicidal thoughts, plans, and attempts.

On the finding that far more patients reported suicidal thoughts than reported depression, Dr. Raja says, “Suicidality is also distinct from depression in patients with mood or psychotic disorders, and is more closely related to variables such as impulsivity or physical aggressiveness.

“Some patients with mild or no depressive symptoms present serious suicidal behavior, whereas others with extremely severe depression show no suicidal behavior.”

Since suicidal thoughts were linked to greater Asperger’s traits, there may be a direct link between Asperger’s syndrome and suicidal behavior. “This study highlights the need to develop appropriate psychological and psychopharmacological therapies,” he writes.

“The rigid thinking style and lack of imagination (i.e. not being able to see any other way out) that is typical of Asperger’s syndrome might respond well to psychological interventions.”