Background 

The dual-continua model of mental health suggests that mental illness and mental wellbeing reflect distinct continua, rather than the extreme ends of a single spectrum. This novel conceptualisation of the relationship between wellbeing and mental illness has significant implications on the way we measure and promote mental wellbeing, and prevent, treat, and recover from mental illness.

Aims

This presentation will summarise the findings of three related studies, focused on the dual-continua model of mental health and the assessment of wellbeing in the context of mental illness and psychological distress 

Method

The presentations include (1) a scoping review of the evidence and implications of the dual-continua model of mental health, (2) a meta-analytic factor analysis of the structure of a wellbeing measure, the Mental Health Continuum – Short Form (MHC-SF) in clinical and non-clinical populations (n=108,603), and (3) a cross-sectional analysis of measurement invariance of the MHC-SF in distressed and non-distressed members of the general population (n=8,406).

Results

Study (1) identified 83 empirical articles, including cross-sectional, longitudinal and intervention studies, which found overall support for the dual-continua model of mental health over the traditional bipolar model. Study (2) showed a consistent factor structure of the MHC-SF across clinical and non-clinical populations, however moderator analysis indicated that there were significant differences in the item loading on the latent factors. Study (3) demonstrated that the MHC-SF is metric non-invariant, indicating that wellbeing items may be interpreted and valued differently in distressed and non-distressed individuals.  

Conclusion

These studies indicate that total and subscale scores of measures of wellbeing may not be equivalent between clinical or distressed and non-clinical populations, and caution is required when making comparisons between them. The presentation concludes that the dual-continua model of mental health is valid and has a range of important implications for mental health research and practice, however a need remains for improved assessment tools that are invariant to participant distress or clinical status.