Does social support modify the effect of disability acquisition on mental health? A longitudinal study of Australian adults

PURPOSE: Disability acquisition in adulthood is associated with deterioration in mental health. Social support may act as a "buffer" against poor mental health following disability acquisition. We tested the hypothesis that women and men with low social support experienced larger declines in mental health on acquisition of a disability compared to women and men with high social support. METHODS: We assessed whether social support, measured both prior and subsequent to disability acquisition, modified the association between disability acquisition and mental health using 14 annual waves of data from the Household, Income and Labour Dynamics in Australia Survey. Participants reported at least two consecutive waves of disability preceded by at least two consecutive waves without disability (2200 participants, 15,724 observations). Fixed-effects linear regression models were used to estimate average differences in mental health between waves with and without disability, for women and men separately. We tested for effect measure modification of the association by social support, including a three-way interaction between disability and social support prior and subsequent to disability acquisition. RESULTS: Though the effects of disability acquisition on mental health were much larger for women, for both women and men there was a consistent pattern of association with social support. There was evidence that social support modified the association between disability acquisition and mental health, with the largest effects for those experiencing a change from high to low social support subsequent to disability and for people with consistently low social support. CONCLUSIONS: These findings highlight the importance of developing new policy and practice strategies to improve the mental health of people with disabilities, including interventions to promote social support at the time of disability acquisition.