Abstract: Objective This study aims to analyse in depth the knowledge, beliefs and behaviours of the elderly population regarding mental health from an active health perspective, and to identify the underlying mechanisms of influence. Methods Using a convenience sampling method, 311 elderly people were surveyed using the self-designed questionnaire on the current situation of mental health of the elderly from the perspective of active health, and the data obtained were processed using SPSS 25.0 software and analysed using descriptive statistical analysis, t-test, one-way analysis of variance (ANOVA), multivariate linear regression analysis and mediation analysis. Results The mean score of mental health knowledge of older people from an active health perspective was (6.47±1.84); the mean score of attitude was (7.10±1.82); and the mean score of behaviour was (5.78±1.92). Regression analysis showed that ethnicity, annual income, literacy level and medical expenses were the influencing factors of knowledge and behaviour; and the mean score of annual income, literacy level, exercise situation and medical expenses were the influencing factors of attitude. Mediation analysis showed that mental health knowledge predicted attitude (β=0.577, P<0.001), behavioural intention (β=0.190, P<0.01)and behaviour (β=0.373, P<0.001), and that attitude positively predicted behavioural intention (β=0.244, P<0.01)and behaviour (β=0.120, P<0.05). Behavioural intentions positively predicted behaviour (β=0.321, P<0.001). The value of the direct effect of knowledge on behaviour was 0.389 or 68% of the total effect and the value of the indirect effect was 0.183 or 32.01% of the total effect. Conclusion The level of mental health knowledge and attitudes among the elderly is at a medium level, and the level of behaviour change is low; mental health attitudes and behavioural intentions play a partial mediating role between knowledge and behaviour.

Key words: active health, older people, mental health, knowledge, beliefs and behaviours