Polypharmacy in psychiatry represents a relevant clinical and pharmacoepidemiological issue, associated with an increased risk of drug interactions, adverse effects, reduced treatment efficacy, and impaired adherence to therapy.

The aim of this study was to investigate the prevalence and clinical assessment of polypharmacy in psychiatric practice using the Medication Appropriateness Index (MAI) and the Interaction Intensity Index (III).

The analysis was based on data retrieved from PubMed, Scopus, Web of Science, Google Scholar, and Medscape for the period 2010—2025, employing a structured methodology for assessing the prevalence and quantitatively evaluating polypharmacy through validated instruments (MAI and III).

The results showed that the prevalence of polypharmacy in psychiatry ranges from 35 % to over 80 %, depending on the clinical diagnosis, patient age, pharmacotherapy profile, and country of study. In most studies, the MAI exceeded 11 points, indicating clinically significant polypharmacy. The III values in typical treatment combinations surpassed 30—40 %, suggesting a high burden of potential drug interactions.

The application of validated tools to assess polypharmacy enables the identification of potentially irrational and clinically hazardous psychopharmacological regimens. This approach contributes to treatment personalization, reduction of adverse interactions, and the development of safe and effective therapeutic strategies for managing mental disorders.