In Australian general practice, psychotropic prescribing for patients with dementia fell over a decade—especially antipsychotics. But by 2020, almost one in five still received multiple psychotropic medicines. The study starts with a gap: little research had evaluated trends in psychotropic prescribing and polypharmacy in primary-care patients, especially those with dementia.

It examined Australia from 2011 to 2020 using MedicineInsight. The analysis included patients aged sixty-five years or more with a recorded dementia diagnosis, and measured psychotropic prescriptions within the first six months of each year. Their results were compared with propensity-score-matched controls without dementia.

Before matching, the study included twenty-four thousand seven hundred one patients with dementia and seventy-two thousand one hundred five without a recorded dementia diagnosis. The scale of the problem is substantial: more than fifty-five million people live with dementia globally, and more than four hundred thirty-six thousand live with dementia in Australia.

Two-thirds of people with dementia in Australia live in the community. Behavioural and psychological symptoms of dementia can include agitation, aggression, depression, anxiety, delusions, and hallucinations. These symptoms are associated with decreased quality of life, hospitalisations, and increased healthcare costs.

The evidence for psychotropic medicines in behavioural and psychological symptoms of dementia is inconsistent. Antipsychotics are effective in only approximately one in five people with dementia for short-term management of significant agitation, aggression, and psychosis.

Antipsychotics and benzodiazepines are associated with a decline in cognition and increased risks of falls, stroke, and all-cause death. Patients with dementia with Lewy bodies may experience severe adverse reactions when taking antipsychotics. Earlier Australian research focused mainly on long-term or residential aged-care facilities.

One study reported that nearly two-thirds—sixty-one percent—of people in Australian residential aged care regularly took psychotropic drugs. That study found psychotropic polypharmacy in twenty-five point six percent of residents, but it could not examine prescribing specifically in patients with dementia because diagnoses were not recorded.

MedicineInsight is a dataset extracted from electronic health records maintained by general practitioners during usual clinical care. It contains sociodemographic information, diagnoses, prescriptions, clinical encounters, observations, and laboratory tests. The study included data from four hundred twenty-three general practices that met standard data-quality criteria, and the dataset represents the Australian population in terms of sex and age.

The dataset contained forty-seven thousand one hundred fifty-eight patients with a documented dementia diagnosis and one hundred thirty-seven thousand one hundred twenty controls. Patients needed at least three recorded encounters at the same practice between January first, 2011, and December thirty-first, 2020.

For each year, the analysis included regular patients aged sixty-five years or more, defined as having at least three practice visits in the previous two years. Patients with dementia also needed at least one year of data after their recorded diagnosis.

Figure one traces how the study population was assembled from MedicineInsight records. On the dementia side, forty-seven thousand one hundred fifty-eight recorded cases were narrowed to twenty-four thousand seven hundred one with at least three clinical visits and a dementia diagnosis dated between twenty-eleven and twenty-nineteen, while later diagnoses were excluded.

The control pathway similarly yielded seventy-two thousand one hundred five patients with at least three recorded visits, making the eligibility process and its exclusions transparent before matching. For each year, the study constructed a dementia group and a matched control group using one-to-one propensity-score matching.

Matching used sex, age, rurality, socioeconomic status, and a broad list of medical conditions. The conditions included those with a compelling indication for psychotropic medicines, so differences between groups would reflect use associated with dementia.

Socioeconomic status was ranked from one, most disadvantaged, to five, most advantaged. Psychotropic polypharmacy was defined as at least two recorded prescriptions of unique medicines within the first six months of the year.

The study counted medicines from six classes: antipsychotics, anxiolytics, hypnotics, antidepressants, opioids, and antiepileptics. The researchers performed ten consecutive serial cross-sectional analyses, calculating the proportion of patients aged sixty-five years or more prescribed psychotropic polypharmacy from 2011 through 2020.

Each proportion included a ninety-five percent confidence interval. The proportions were compared with propensity-score-matched controls without dementia. Temporal trends were shown in graphs, and a Cochran-Armitage test assessed statistical significance.

Before matching, the study included twenty-four thousand seven hundred one patients with recorded dementia and seventy-two thousand one hundred five controls. In both groups, fifty-nine point two percent were female. The number of patients aged sixty-five years or more in the dementia groups increased from four thousand four hundred in 2011 to nine thousand eight hundred twenty-five in 2020.

One-to-one matching made the matched control total the same as the dementia total in each index year. Table one describes the dementia groups and their one-to-one matched controls in twenty eleven, twenty fourteen, twenty seventeen, and twenty twenty.

Each group has equal sample sizes, increasing from four thousand four hundred to nine thousand eight hundred twenty-five, while the table reports age, sex, rurality, socioeconomic quintile, state, and comorbidities. It matters because these characteristics show how the matched comparison groups were structured across the study period.

Antipsychotic use in the dementia groups was at least double that of matched controls between 2011 and 2020. In the dementia group, it declined from fifteen point nine percent to eight point eight percent. Antipsychotic use also declined among matched controls, from six point two percent to four point five percent.

Among people aged eighty-five years or older with dementia, prescribing remained highest, although it fell from nineteen point eight percent in 2011 to twelve point eight percent in 2020. Figure two tracks antipsychotic prescribing from 2011 to 2020, comparing dementia groups with matched controls overall and across age, sex, and rurality.

Overall use declined from fifteen point nine percent to eight point eight percent in the dementia group, and from six point two percent to four point five percent in controls. The subgroup panels show that this pattern appears across demographic and geographic categories, while prescribing remains consistently more common among people with dementia.

In 2011, forty-two percent of patients in the dementia group had at least one recorded psychotropic prescription. That proportion declined to thirty-four point two percent by 2020. Among dementia patients with at least one psychotropic medicine, the mean number of individual psychotropic medicines was one point nine in 2011 and two point zero in 2020.

In matched controls, it was one point seven in 2011 and one point eight in 2020. Figure three tracks the percentage of primary-care patients prescribed at least one, two, or three psychotropic medications within six months, comparing dementia patients with matched controls from 2011 to 2020.

In the dementia group, at least one prescription declined from forty-two percent in 2011 to thirty-four point two percent in 2020, while prescribing three or more medications also generally decreased. The figure matters because it shows both overall exposure and psychotropic polypharmacy over time, highlighting continued prescribing in dementia care.

Psychotropic polypharmacy was higher in the dementia groups than in matched controls. In the dementia groups, it decreased from twenty-one point seven percent in 2011 to eighteen point one percent in 2020. Prescribing three or more psychotropic medicines fell slightly in dementia groups, from nine point six percent to eight point five percent.

In matched controls, it increased from five point seven percent to seven percent. A sensitivity analysis using unmatched dementia and control groups found a similar polypharmacy trend to the matched-group analysis. Figure 4 tracks psychotropic polypharmacy from 2011 to 2020 by sex, age, and rurality, comparing dementia groups with matched controls.

The authors show higher levels among females and particularly persistent levels in dementia patients aged eighty-five years or older. By rurality, prevalence was highest outside major cities: among dementia patients in outer regional, remote, and very remote areas, it fell from 30.3 percent in 2012 to 21.5 percent in 2020, while inner regional areas declined from 25.5 percent in 2011 to 20.4 percent in 2020.

Psychotropic polypharmacy in the dementia groups declined from twenty-one point seven percent in 2011 to eighteen point one percent in 2020. This was lower than the twenty-five point six percent reported by a previous Australian study.

It was also lower than the thirty-three percent reported by an international meta-analysis involving twenty-five studies from twelve countries in residential aged care dementia patients. The study used recorded prescriptions, so it could not confirm whether medicines were dispensed or taken.

Prescriptions written by non-GP specialists were not recorded in MedicineInsight. A strength was that controls and patients were matched using an extensive list of comorbidities. Another strength was the finding that among people aged eighty-five years or older, dementia patients had approximately twenty-five percent psychotropic polypharmacy compared with approximately fifteen percent in controls.

From 2011 to 2020, prescribing and polypharmacy declined among Australian primary-care patients with dementia, but multiple psychotropic use remained common, particularly outside major cities and among the oldest patients.