There are some limitations to the study. Firstly, the cross-sectional design precluded us from drawing conclusions on causal-relationships. Secondly, although the interviewer-administered questionnaire could ensure the response quality, respondents might alter their response to avoid embarrassment in the presence of an interviewer  or they may be reluctant to reveal beliefs unlikely to be endorsed by the interviewer i.e. there may have been some social desirability bias . Thirdly, previous studies suggested that people tended to have different attitudes towards different mental illnesses . However, in our study, the participants were asked to answer the questionnaire based on the general term, ‘mental illness’. As a result, their responses were highly dependent on how they interpreted this term, and thus might be inconsistent across the sample. Lastly, although several robust strategies were employed to ensure the conceptual equivalency of the assessment instruments in different languages, it is still possible that languages differences contributed to some of the significant findings in our study (e.g. difference by ethnicity groups).