OBJECTIVE Psychiatric care in general hospitals depends on collaboration with non-psychiatrist doctors. The Doctors' Attitudes toward Collaborative Care for Mental Health (DACC-MH) is a two-factor scale designed to address this issue and validated in the UK in 2010. However, its applicability in contemporary, culturally diverse settings is unknown and therefore this study was aimed at determining its validity and consistency using data from our 2021 international study. Confirmatory and exploratory factor analyses were used, comparing results from our 2021 study (n = 889) with those from the 2010 UK study (n = 225). RESULTS The DACC-MH consultation subscale, but not the management subscale, aligned with data from our larger, international study. The 2-factor model failed the Chi-square goodness of fit test (χ2(19) = 53.9, p < 0.001) but had acceptable other fit indices. While the previously identified attitudinal difference between physicians and surgeons was replicated, measurement invariance for this result could not be established. Exploratory factor analysis suggested a 6-factor model, contrasting with the 2-factor model proposed in 2010 for the UK sample. The DACC-MH scale shows significant limitations when applied to a larger, international dataset. Cultural and generational differences in doctors' attitudes appear relevant and should be considered in assessing barriers to psychiatric care in general hospitals.