Trend of antipsychotic monotherapy
The rate of antipsychotic monotherapy in 2001, 2006, 2011, 2016 and 2021 were 32.0%, 33.7%, 32.8%, 37.6% and 41.5%, respectively, and the rate of dual-agent antipsychotic use were 36.7%, 37.4%, 39.4%, 41.9% and 41.9%, respectively (Table 1). The rate of patients taking three or more drugs were 18.7%, 18.5%, 18.0%, 14.0% and 9.4%, respectively (Table 1).
The average number of antipsychotic medications taken trended downward from 2.0 to 1.7 (r = -0.938, p = 0.018) (Table 2). The percentage of patients receiving complete antipsychotic monotherapy without psychotropic medications other than antipsychotics in 2001, 2006, 2011, 2016 and 2021 were only 2.5%, 4.5%, 5.9%, 7.7% and 8.8%, but and increased significantly (χ2 = 32.3, df = 1, p = 1.3x10-8) (Fig 1). On the other hand, the rate of SGA use in 2001, 2006, 2011, 2016 and 2021 were 28.9%, 49.2%, 61.4%, 65.4% and 70.5%, respectively, and when analyzing the prescription rates of these drugs over the past 20 years, the trend over the past 20 years was an increasing trend (χ2 = 286.2, df = 1, p<2.2x10-16) (Table 2). The average number of SGAs used trended upward from 1.1 to 1.3 (Table 2). The rate of SGA monotherapy use was in 2001, 2006, 2011, 2016 and 2021 were only 9.1%, 16.3%, 18.9%, 23.2% and 29.3%, respectively, but there was an increasing trend over the past 20 years (χ2 = 32.3, df = 1, p = 1.3x10-8) was observed (Fig 1). The complete monotherapy rates for SGAs without other psychotropic medications in 2001, 2006, 2011, 2016 and 2021 were only 0.7%, 2.7%, 3.5%, 5.0% and 6.3%, respectively, but the rates showed an increasing trend over the past 20 years (χ2 = 37.6, df = 1, p = 8.9x10-10) (Fig 1). On the other hand, the rate of FGA use in 2021 was 54.8%, and a decreasing trend was observed over the past 20 years. The average number of FGAs used trended downward, from 1.9 to 1.4 (Table 2).