2.3 | Statistical analyses
We calculated the total count and proportion of participants in each age
group who had been dispensed an antipsychotic antidepressants,
anxiolytic, or hypnotic between 2013 to 2022 during each of these years.
We evaluated the effect of time, age, and sex on the dispensing of these
medications using logit models for the analysis of panel data. The
results of these analyses were summarised by the odds ratio (OR) and
respective 99.9% confidence interval (99.9%CI). Reference groups were
2013, age 0-9 years, and male sex. Because of the very large sample and
the risk of type I error, we set alpha at 0.1% (p≤0.001). All tests
were two-tailed.
3 | RESULTS
The PBS file included 16,389,245 records (Table 1). Of all records,
54.10% were for females. Figure 1 shows the proportion of participants
dispensed antipsychotics, antidepressants, anxiolytics, and hypnotics
between 2013 and 2022. There was a decline in the proportion of people
dispensed antipsychotic medications over time, most noticeably amongst
those aged ≥ 80 years. The dispensing of antipsychotics was highest
among those aged 80-89 and 90 years or over. There was minimal
difference between the age groups 30 to 69 years in the dispensing of
antipsychotics. About 1 in every 6 people in the PBS database were
dispensed an antidepressant. The 80-89 and ≥90-year age-groups were the
most frequently dispensed antidepressants. There was a progressive rise
in the proportion of people dispensed antidepressants over time, with a
noticeable sharp increase after 2019 among people aged 10-19 (8.36%
from 2013 to 2022), 20-29 (9.87% from 2013 to 2022) and 30-39 years
(4.44% from 2013 to 2022). The dispensing of anxiolytics was highest
among the older age groups, although the proportion of people aged 60
years or over dispensed anxiolytics declined with time, particularly
after 2014. A similar pattern of dispensing was observed for hypnotics.
The odds of females being dispensed an antipsychotic were lower compared
with males (OR=0.74, 99.9%CI=0.72-0.76), but higher for the dispensing
of antidepressants (OR=2.71, 99.9%CI=2.66-2.77), anxiolytics (OR=1.58,
99.9%CI=1.55-1.61), and hypnotics (OR=1.60, 99.9%CI=1.57-1.64).
As the proportion of the population issued medication scripts is
relatively low among young people, we adjusted our calculations for the
estimated likely denominator for the relevant
age-group.7 The results of these analyses are
displayed in Figure 1. The proportion of Australians aged 10-19, 20-29
and 30-39 years dispensed antidepressants increased from 2.92% to
5.93%, 7.74% to 12.44%, and from 10.13% to 12.65% between 2013 and
2022.
4 | DISCUSSION
Our results show that a large proportion of Australians accessing
community pharmacies are dispensed psychotropic medications,
antidepressants being the most frequent among them. We found that older
adults, most noticeably those aged 80 years or over, were the most
frequent recipients of antipsychotics, antidepressants, anxiolytics, and
hypnotics, although the proportion of older adults dispensed
antipsychotics, anxiolytics and hypnotics has declined over the past 10
years, particularly after 2015. We also found that an increasing
proportion of participants were dispensed antidepressants between 2013
and 2022, with the most marked rise occurring amongst those aged 10-19
and 20-29 years. A larger proportion of females than males were
dispensed antidepressants, anxiolytics, and hypnotics, but a greater
proportion of males than females were dispensed antipsychotics, albeit
not in later life.
Access to the large PBS database allowed us to examine the dispensing
patterns of medications in Australia between 2013 and 2022, with
evidence from other sources suggesting that the agreement between
dispensing and medication use is high.8 One important
caveat of this dataset is that the numbers reflect only the people who
have been dispensed a medication during the relevant time-period (not
necessarily a psychotropic drug). This is the case for about 54% of
people aged 0-17 years, but only 2% of those aged 80 years or
over.7 As a result, prevalence estimates are likely to
be inflated for the population of young and middle-aged people, but
should be relatively accurate for older people. Hence, the observed
discrepancy in the use of psychotropic medications between older and
younger people could be even more pronounced than our calculations using
the crude PBS data suggest. Our additional analyses yielded results that
are consistent with this hypothesis (Figure 1).
The proportion of people dispensed antipsychotics, anxiolytics and
hypnotics declined over the 10 years of the study, but the proportion of
those receiving antidepressants increased. This rise in the proportion
of people dispensed antidepressants has been observed in
some,9 but not all, countries,10 and
has recently been portrayed as a consequence of the COVID-19 pandemic
or, alternatively, of stockpiling of medications triggered by
uncertainty surrounding the medium and long term consequences of
lockdowns.11 Our analyses suggest that stockpiling is
an unlikely explanation for our findings, as rises in the dispensing of
psychotropics were not apparent for other medication classes. They also
suggest that the pandemic may have affected the mood of adolescents and
young adults more markedly, although upwards trends in the dispensing of
antidepressants had been apparent for at least five to six years
earlier. Such a change may reflect an increase in the prevalence of mood
disorders in the community (particularly among adolescents and young
adults),12 changes in diagnostic
practice,13 or a shift in prescription habits that
have led to progressively greater use of antidepressants for the
management of conditions other than depression (such as anxiety
disorders).14 The concurrent decline in the use of
other psychotropic medications could further be viewed as an indication
that the dispensing of antidepressants may be increasingly used for the
management of conditions other than depressive disorders. In addition,
sex differences in the dispensing of psychotropics may have been due to
real discrepancies in the prevalence of mental health disorders treated
by these medications, or may represent differing gender-mediated
help-seeking behaviours.15
In conclusion, our results indicate that older adults and females have
been, and continue to be, the most frequent recipients of psychotropic
medications dispensed in Australia over the past decade. The
organisation and resourcing of health services should reflect this
reality.
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FIGURE LEGEND
Figure 1. The figure shows the proportion (%) of people
included in the 10% PBS database who were dispensed antipsychotics (top
left), antidepressants (bottom left), anxiolytics (top right), and
hypnotics (bottom right) between 2012 and 2021 according to their age
groups (coloured lines). The estimates depicted in the figure were
adjusted for the proportion of people expected to have been missed in
each age-group because they were not included in the PBS
database.7