Harmony software, developed explicitly for psychologists and social scientists, plays a pivotal role in harmonising diverse questionnaire items. One of the areas where Harmony can be significantly impactful is in comparing the Patient Health Questionnaire-9 (PHQ-9) and the Antisocial Behaviours Questionnaire (ABQ). The PHQ-9 vs ABQ comparison is crucial to understanding various mental disorders and antisocial behaviours. The PHQ-9 is a widely used tool for diagnosing mental disorders, with each question scoring from “0” (not at all) to “3” (nearly every day). On the other hand, the ABQ targets antisocial behaviour patterns, though its items are not specified. Harmony, with its AI-powered natural language processing, offers an efficient way of harmonising the items in both the PHQ-9 and ABQ. It provides a percentage match between each item in PHQ-9 vs ABQ, aiding researchers in identifying overlapping or similar constructs. Crucially, Harmony can complete this PHQ-9 vs ABQ comparison in multiple languages, leveraging its expansive database. This allows for broader applications and thorough understanding on a global scale. We highly recommend researchers to utilise Harmony for comparing PHQ-9 and ABQ, making the most out of the existing cohort and longitudinal studies. Visit Harmony’s web interface and start your PHQ-9 vs ABQ comparison efficiently and effectively.