Stability and change in level of probable depression and depressive symptoms in a sample of middle and older-aged adults

<jats:title>ABSTRACT</jats:title><jats:p><jats:bold>Background:</jats:bold>Findings from studies investigating depression in adults in late life are mixed due to a lack of large longitudinal studies with the power necessary to yield reliable estimates of stability or change. We examined the long-term stability of probable depression and depressive symptomology over a 13-year period in the Dynamic Analyses to Optimize Ageing (DYNOPTA) project.</jats:p><jats:p><jats:bold>Methods:</jats:bold>Community-living participants (<jats:italic>N</jats:italic>= 35,200) were aged 45–103 at baseline, predominantly female (79%), partnered (73%), and educated to secondary school only (61%) and followed for up to 13 years.</jats:p><jats:p><jats:bold>Results:</jats:bold>At baseline, increased age was associated with lower prevalence of probable depression and depressive symptomology. Over time, prevalence of probable depression was stable while levels of depressive symptomology reported a small decline. However, this finding was not consistent for all age groups; there was evidence for increasing levels of depressive symptomology, but not probable depression, as individuals aged. This effect was particularly notable among males aged 70 plus years.</jats:p><jats:p><jats:bold>Conclusions:</jats:bold>These results answer important questions relating to the longitudinal prevalence of probable depression and depressive symptomology in a sample of older Australians. These findings have policy implications for mental health service provision for older adults.</jats:p>