Trends in calls to a state poisons centre and presentation to emergency departments for intentional antidepressant overdose in Victoria, Australia

Objective: To describe the rates and trends of emergency department presentations and calls to a state poisons centre for antidepressant overdose. Methods: A retrospective cohort study utilising the Victorian Emergency Minimum Dataset and Victorian Poisons Information Centre call registry between January 2009 and December 2018 was conducted. This captured all presentations to Victorian emergency departments and calls to the Victorian Poisons Information Centre. Any intentional overdose involving an antidepressant was included. Annual rates of emergency department presentations and calls per 100,000 persons and 100,000 prescriptions for antidepressants overall and individual antidepressant classes, in addition to age-group-specific rates, were reported. Results: A total of 3650 presentations to emergency department and 7096 calls to the poisons centre were included. No changes were seen in overall emergency department presentation rates when controlled for population or prescription numbers, but large and significant increases were seen for younger age groups. The 10–14- and 15–19-year age groups had average annual increases of 13.1% (95% CI = [6.5%, 19.7%], p < 0.001) and 7.2% (95% CI = [2.8%, 11.5%], p < 0.001) per 100,000 persons, respectively. Increases were seen in overall annual call rates of 6.7% (95% CI = [5.2%, 8.1%], p < 0.001) per 100,000 persons and 7.5% (95% CI = [4.9%, 10.1%], p < 0.001) per 100,000 prescriptions. Conclusion: Overall, emergency department presentation rates remained stable during the study period. Overall poisons centre call rates increased moderately. However, when examining younger persons, large increases were seen in both emergency department presentations and poison centre call rates. These findings highlight the need for future interventions to mitigate against intentional overdose in younger populations.