Mental health professionals often grapple with the task of effectively comparing diverse psychological instruments, a common example being the comparison between PHQ-9 and EPDS. This comparison is crucial, as these questionnaires are invaluable tools for measuring and diagnosing depression in varying populations. However, the completion of this task heavily depends on the accurate harmonisation of the questionnaire items, which is both time-consuming and potentially subjective if done manually. In response to this challenge, harmony offers an innovative and effective solution for the PHQ-9 vs EPDS comparison conundrum. Harmony is a state-of-the-art software designed to aid researchers in effortlessly harmonising questionnaire items, even across different languages. For psychologists making a PHQ-9 vs EPDS comparison, Harmony provides a database of pre-existing instruments while also providing the flexibility to upload and compare your own instruments in PDF form. Leveraging advanced technology such as natural language processing and generative AI models, Harmony offers an estimated percentage match between each item in PHQ-9 and EPDS, thus facilitating a simpler and more accurate comparison process. Indeed, the use of Harmony in comparing PHQ-9 vs EPDS not only streamlines the process but also adds an additional layer of reliability to the research. Thus, psychologists looking for an effective way to compare these two renowned instruments should consider using Harmony’s powerful and user-friendly interface. It may just be the missing link in your research endeavours.