Suicide attempts by self-poisoning in the United States among 10–25 year olds from 2000 to 2018: substances used, temporal changes and demographics

Objective: To evaluate the substances used, outcomes, temporal and demographics associated with suicide attempts by self-poisoning in children and young adults aged 10–25 years old from 2000 to 2018.Methods: This is a retrospective review of suspected-suicide self-poisoning cases reported to the National Poison Data System (NPDS) from US Poison Centers from 2000 to 2018 for patients 10–25 years old. For comparison of annual rates, we obtained population data by year of age from the US Census Bureau. We evaluated changes in: monthly and annual incidence/rate per 100,000 population, substances used and outcome by patient age and demographics.Results: There were 1,677,435 cases of suicide attempt by self-poisoning among individuals 10–25 years old reported to US PCCs from 2000 to 2018. There were 410,940 self-poisoning cases (24.5%) with a serious medical outcome, and the proportion of exposures that resulted in a serious medical outcome increased with increasing age group. For the age groups of 10–12, 13–15 and 16–18 years of age, there was a significant increase after 2011, which was influenced primarily by females. The substance groups with the greatest number of serious medical outcomes were OTC analgesics, antidepressants, antihistamines and antipsychotics. ADHD medications were common in the younger age groups of 10–15 years, while the sedative/hypnotics occurred more commonly in the older age groups. The groups with the greatest increase in serious medical outcomes after 2011 were antidepressants, OTC analgesics, antihistamines and ADHD medications. Opiates were less commonly involved (7.4%) in cases with serious medical outcomes and decreased significantly in the 19–25 year-old age groups after 2012. States with a lower population per square mile had a greater number of reported cases with serious medical outcomes. There was a significant decrease in the number of cases in the age groups of 10–18 years during the traditional non-school months of June–August compared with September–May. This seasonal trend occurred among cases with all outcomes and among cases with serious medical outcomes. This decrease did not occur in the age group of 19–21 years, and there was an increase during summer months in the age group 22–25 years.Conclusions: The substances used during self-poisoning varies by age group but appears to include substances available to that age group, with a significant increase after 2011, increased rates in more rural states, and a seasonal variation of increased rates during school months among adolescents but not among young adults. Two of the top substances, OTC analgesics and antihistamines, in all age groups, comprising more than a third of all substances used, are widely available over-the-counter with no restrictions regarding access. Of additional concern, ADHD medications had the highest risk of a serious medical outcome.