Abstract
BACKGROUND: Mental illness and mental well-being are independent but correlated dimensions of mental health. Both are associated with social functioning (in opposite directions), but it is not known whether they modify the effects of one another. New treatment targets might emerge if improving mental well-being in people with serious mental illness improved functional outcomes independent of clinical status. AIMS: To describe associations between mental well-being and functioning in people classified according to mental illness status. METHOD: Cross-sectional data from 5485 respondents to the Health Survey for England 2014 were analysed. Mental illness status (including whether diagnosed by a professional) was by self-report and grouped into four categories, including 'diagnosis of serious mental illness'. Mental well-being was measured using the Warwick-Edinburgh Mental Well-Being Scale, and functioning by items from the EQ-5D. Mental distress was assessed using General Health Questionnaire (GHQ-12) items. Associations were examined using moderated regression models with group membership as an interaction term. RESULTS: Mental well-being score was associated with (higher) functioning score (P < 0.05). This association varied between mental illness groups, even after adjusting for age, gender, ethnicity, physical health and symptoms of mental distress (F(3) = 14.60, P < 0.001). The gradient of this association was greatest for those with diagnosed serious mental illness. CONCLUSIONS: Mental well-being was associated with higher functional status in people with mental illness, independent of the symptoms of mental distress and other confounders. The association was strongest in the diagnosed serious mental illness group, suggesting that mental well-being may be important in recovery from mental illness.