Substance abuse problems were more prevalent among those with autism spectrum disorder (ASD) than among sex- and age-matched controls, according to a Taiwanese study.
A retrospective analysis of nearly 6,600 people found that those with autism had a significantly higher risk for substance use disorder (SUD) than those without autism (adjusted hazard ratio 2.33, 95% CI 1.89-2.87), reported Chih-Sung Liang, MD, of the National Defense Medical Center in Taipei, and colleagues.
As shown in their study online in JAMA Pediatrics, the risk was driven mainly by a three-fold increased risk for drug use disorder (aHR 3.00, 95% CI 2.15-4.58), followed by a two-fold higher risk for alcohol use disorder (aHR 2.07, 95% CI 1.60-2.63).
In addition, those with autism and co-morbid substance use disorder had a more than three-fold higher risk of death (aHR 3.17, 95% CI 2.69-3.89) during an average follow-up period of 8.1 years.
Interestingly, the researchers said, people who were taking psychotropic agents for the treatment of their autism had a reduced risk of developing SUD. Those receiving one agent saw a 40% reduced risk for SUD (HR 0.60, 95% CI 0.43-0.66), while those taking multiple agents had a 63% reduced risk (HR 0.37, 95% CI 0.28-0.49). And those on multiple agents with a cumulative defined daily dose above 365 saw the lowest risk for developing SUD (HR 0.28, 95% CI 0.21-0.40).
“In other words, the risk of SUD could be reduced if patients with ASD maintain a stable condition,” Liang’s group said. “This finding should remind psychiatrists and the families of patients with ASD of the importance of ASD treatment.”
Future research, the team said, could aim to see if there is a similar risk reduction with non-pharmacotherapies for autism such as behavioral therapy, family therapy, or psychotherapy.
Drawing upon data from both the inpatient and outpatient data from the Taiwan National Health Insurance Research Database, the researchers assessed 6,599 individuals with ASD who had at least three outpatient visits within 1 year for symptomatic autism, as defined by ICD-9 codes, between 2000 and 2015.
A total of 77% in the group were male patients with an average age of 12, who were then compared with 26,296 non-ASD controls with records in Taiwan’s Longitudinal Health Insurance Database. Cases and controls showed similar levels of education and income on average.
Several psychiatric comorbidities were more prevalent among individuals with ASD, including intellectual disability, attention deficit hyperactivity disorder, tic disorder, epilepsy, obsessive-compulsive disorder, mood disorder, anxiety disorder, and impulse control disorder.
But people with autism still had a higher risk of having SUD compared with matched controls with the same comorbidities.
The risk for substance abuse was also higher among those with autism and certain specific psychiatric comorbidities. Those not taking any psychotropic agents for autism with a comorbid tic disorder saw one of the highest risks for SUD (aHR 6.39, 95% CI 5.11-7.87). And those with comorbid impulse control disorder had over five-fold higher risks for alcohol and drug use disorders (aHR 5.48, 95% CI 5.12-5.70 for alcohol; aHR 5.42, 95% CI 5.12-5.80 for drug).
Calling these “critical findings,” the authors of an accompanying editorial said that while the study adds a “noteworthy body of evidence to the limited studies” on this association, the results are somewhat limited by use of the “umbrella term” of substance use disorder. It would therefore be beneficial to further clarify the specific type of drug abuse seen among people with autism in future studies, said Sarah Ann Anderson, MD, PhD, and Marina Catallozzi, MD, MSCE, both of Columbia University in New York City.
Nonetheless, the editorialists emphasized, screening for SUD among these patients is important, and this should be “a call to action” for healthcare providers and most specifically pediatricians, who are most often the ones who are treating patients with ASD.
The study was supported by grants from Taipei Veterans General Hospital, the Ministry of Science and Technology in Taiwan, and from the Tri-Service General Hospital Research Foundation.
Liang and co-authors reported no conflicts of interest.
Anderson and Catallozzi reported no conflicts of interest.