Trends in the utilisation of psychotropic medications in Australia from 2000 to 2011

Abstract

Objective: This study examined longitudinal trends in the dispensing of psychotropic medications in Australia from January 2000 to December 2011. Method: Dispensing data for the major classes of psychotropic medications (antidepressants, anxiolytics, sedatives, antipsychotics, mood stabilisers and attention-deficit hyperactivity disorder (ADHD) medications) were obtained from the Drug Utilisation Sub-Committee of the Australian Department of Health and Ageing. Results were expressed in terms of defined daily doses/1000 population/day (DDDs/1000/day). Results: There was a 58.2% increase in the dispensing of psychotropic drugs in Australia from 2000 to 2011, driven by major increases in antidepressants (95.3% increase in DDDs/1000/day), atypical antipsychotics (217.7% increase) and ADHD medications (72.9% increase). Dispensing of anxiolytics remained largely unchanged, while sedatives and typical antipsychotics decreased by 26.4% and 61.2%, respectively. Lithium dispensing remained static while valproate and lamotrigine increased markedly. In 2011, antidepressants accounted for 66.9% of total psychotropic DDDs/1000/day totals, far greater than anxiolytics (11.4%), antipsychotics (7.3%), mood stabilisers (5.8%), sedatives (5.5%), or ADHD medications (3.0%). Sertraline, olanzapine, valproate and methylphenidate were the most frequently dispensed antidepressant, antipsychotic, mood stabiliser and ADHD medication, respectively, while diazepam and temazepam were the most commonly dispensed anxiolytic and sedative. Conclusions: Psychotropic utilisation markedly increased in Australia between 2000 and 2011. Some potential concerns include: (1) the continuing high use of benzodiazepines, particularly alprazolam, despite their problematic effects; (2) the rapid increase in serotonin noradrenaline reuptake inhibitor (SNRI) use, given their more complex side-effect profile relative to selective serotonin reuptake inhibitors (SSRIs); and (3) the dramatic increase in antidepressant prescriptions despite questions about the efficacy of these drugs in mild to moderate depression. Finally, some limitations are identified regarding use of the DDDs/1000/day metric, which can distort estimates of utilisation of specific drugs when the defined daily dose is higher or lower than the formulation most commonly dispensed by pharmacies.