Background: Pseudoaldosteronism is a severe primary aldosteronism-like syndrome with decreased plasma aldosterone levels. In Japan, it is often caused by herbal medicines containing licorice. However, there has been little evidence assessing the updated proportion of each drug and its recent trends. Objective: To identify recent major causes of pseudoaldosteronism in Japan and assess the possibility of chronological changes from 2005 to 2020. Methods: We collected data from the Japanese Adverse Drug Event Report (JADER) database, a spontaneous reporting system maintained at Japan's Pharmaceutical and Medical Devices Agency, reported between January 2005 and December 2020. Findings: In the JADER database, reported adverse events of pseudoaldosteronism, hypokalemia, rhabdomyolysis, and myopathy were extracted from 2016 to 2020. The drugs frequently implicated in the development of these pseudoaldosteronism-related events, including Syakuyakukanzoto, Yokukansan, Hochuekkito, Kakkonto, Rikkunshito, Daioukanzoto, Ryoukeijyutsukanto, Hangeshashinto, Bakumondoto, Saireito, were identified. Yokukansan, an herbal medicine increasingly used in the treatment of behavioral and psychological symptoms of dementia (BPSD), was shown to be the second most frequently associated drug with pseudoaldosteronism-related adverse events (232 cases), following Syakuyakukanzoto (255 cases). Furthermore, with regards to adverse events standardized by the content of licorice, Yokukansan was the most common. Between 2005 and 2020, the number of adverse events related to Yokukansan increased significantly, however, those associated with Shakuyakukanzoto did not (Fig. 1). Conclusion: Yokukansan-induced pseudoaldosteronism appears to have increased significantly in Japan. Considering the aging population and limitations of conventional drugs for BPSD, this is an emerging trend and a potentially serious healthcare issue in Japan.