Trends in antipsychotics and lithium use in Scandinavian countries from 2010 to 2023: a cross-country drug utilization study

The use of antipsychotic drugs has increased in recent years, extending beyond traditional indications like schizophrenia and bipolar disorder while the use of lithium has remained stable or declined. However, current data on prescribing trends and dosages in Scandinavian countries are limited. This study aims to analyze trends in the prevalence and dosing of antipsychotics and lithium in Scandinavia from 2010 to 2023. Data were obtained from national prescription registers in Norway, Sweden, and Denmark, covering 2010–2023. For each antipsychotic class, we calculated: one-year prevalence (users per 1,000 inhabitants), therapeutic intensity (Defined Daily Doses [DDD] per 1,000 inhabitants per day), and mean dose (DDD per user per day). These metrics were analyzed overall, by sex, and by age groups. In 2010–2023, overall antipsychotic use increased across all countries, with Sweden (+ 24.4%) and Norway (+ 23.7%) experiencing the largest rises, and Denmark (+ 8.1%) the smallest. Lithium use was stable in Denmark, decreased in Norway, and increased in Sweden. Use was most prevalent among women and adults aged 25–44, primarily driven by a rise in second-generation antipsychotics (SGAs), especially quetiapine. Over the period, quetiapine’s therapeutic intensity increased (e.g., Norway from 1.29 to 2.96 DDD/1,000 inhabitants/day; Sweden from 0.91 to 1.58; Denmark from 2.32 to 3.07), while its mean dose decreased (e.g., Norway from 0.63 to 0.18 DDD/user/day; Sweden from 0.35 to 0.22; Denmark from 0.34 to 0.20), indicating a trend toward low dose prescribing. From 2010 to 2023, prescribing patterns of antipsychotics in Scandinavia shifted toward increased use of SGAs, higher therapeutic intensity, and lower mean doses for most drugs within this class. These trends were especially notable for quetiapine and could be influenced by off-label use. These findings highlight the importance of ongoing monitoring and research that integrates prescription data with clinical information to enhance safety and promote evidence-based prescribing.