Trends in self-poisoning and psychotropic drug use in people aged 5-19 years: a population-based retrospective cohort study in Australia

Abstract

Objectives: To characterise trends in self-poisoning and psychotropic medicine use in young Australians.

Design: Population-based retrospective cohort study.

Setting: Calls taken by the New South Wales and Victorian Poisons Information Centres (2006-2016, accounting for 70% of Australian poisoning calls); medicine dispensings in the 10% sample of Australian Pharmaceutical Benefits Scheme data (July 2012 to June 2016).

Participants: People aged 5-19 years.

Main outcome measures: Yearly trends in intentional poisoning exposure calls, substances taken in intentional poisonings, a prevalence of psychotropic use (dispensing of antidepressants, antipsychotics, benzodiazepines and medicines for attention deficit hyperactivity disorder (ADHD)).

Results: There were 33 501 intentional poisonings in people aged 5-19 years, with an increase of 8.39% per year (95% CI 6.08% to 10.74%, p<0.0001), with a 98% increase overall, 2006-2016. This effect was driven by increased poisonings in those born after 1997, suggesting a birth cohort effect. Females outnumbered males 3:1. Substances most commonly taken in self-poisonings were paracetamol, ibuprofen, fluoxetine, ethanol, quetiapine, paracetamol/opioid combinations, sertraline and escitalopram. Psychotropic dispensing also increased, with selective serotonin reuptake inhibitors (SSRIs) increasing 40% and 35% July 2012 to June 2016 in those aged 5-14 and 15-19, respectively. Fluoxetine was the most dispensed SSRI. Antipsychotics increased by 13% and 10%, while ADHD medication dispensing increased by 16% and 10%, in those aged 5-14 and 15-19, respectively. Conversely, dispensing of benzodiazepines to these age groups decreased by 4% and 5%, respectively.

Conclusions: Our results signal a generation that is increasingly engaging in self-harm and is increasingly prescribed psychotropic medications. These findings indicate growing mental distress in this cohort. Since people who self-harm are at increased risk of suicide later in life, these results may foretell future increases in suicide rates in Australia.

Keywords: clinical pharmacology; public health; toxicology.

Figure 1

Trends in intentional poisonings in children and adolescents reported to the NSWPIC and VPIC, 2006–2016. NSWPIC, New South Wales Poisons Information Centre; VPIC, Victorian Poisons Information Centre.

Figure 2

Number of intentional poisonings by birth year cohort at ages 5–19 years, 2006–2016.

Figure 3

Rolling average of SSRI prevalence (persons/10 000 population/month), in females and males aged 5–14 years (A and B, respectively), and females and males aged 15–19 years (C and D, respectively), July 2012 to June 2016. Data were not shown for medicines where there were <30 persons in 10% sample on that class in at least 1 month examined. SSRI, selective serotonin reuptake inhibitor.