In the Australian population, mental health problems affect one in five people during their lifetime. In the most recent National Health Survey, around 10% reported a long-term mental or behavioural problem (Australian Bureau of Statistics 2006). The most commonly reported problems were classified into two groups, anxiety related problems and mood (affective) problems. Prevalence for each was around 4% for males and 6% for females. Self reported rates were lower in the older age groups than in younger adults (118,800 of 65-74 year olds and 112,000 of those aged 75 years and over). Associated medication usage was higher overall in older age groups, but this was related to sleeping medications (11% amongst those aged 65 years and over compared with 5% for the whole adult population) rather than to antidepressant or anxiolytic usage. According to scores on the K10, around two-thirds (63%) of adults were classified as having low levels of psychological distress, 24% with moderate levels, 9% with high levels and 4% with very high levels. These rates are similar to those reported in the 2001 NHS. There are presently no national data regarding the prevalence of mental health problems amongst Aboriginal and Torres Strait Islander people, although the rates of hospitalisation and death due to ‘mental and behavioural disorders’ e.g. psychoactive substance use and suicide are well known (Australian Institute of Health and Welfare 2004). The commonest forms of mental ill health are anxiety related problems and affective (mood) disorders.
Top of page
DepressionEstimates of the prevalence of depression among older people living in the community vary widely, from 10% to 35% (Beekman, Copeland et al. 1999; Sayer, Britt et al. 2000; Baldwin, Chiu et al. 2002). Amongst mental health problems, depression ranks as a high prevalence condition and warrants particular attention using preventive measures. Whilst the underlying aetiology and mechanisms are yet to be determined, the relationship between physical activity behaviour and depression is bi-directional. Prospective studies demonstrate that people who exercise are less likely to be- or become- depressed (Brosse, Sheets et al. 2002). Cross-sectional and prospective studies of healthy adult populations have shown an association between physical inactivity and depression (Lampinen, Heikkinen et al. 2000; Kritz-Silverstein, Barrett-Connor et al. 2001) and indicate that a low prevalence of depressive symptomatology is related to exercise behaviour (Blumenthal 1999; Lawlor and Hopker 2001; Baldwin, Chiu et al. 2002) (causality can only be attained via controlled trials). Data from the Australian Longitudinal Study on Women’s Health found that depression scores decreased and mental health scores increased with increasing levels of previous, current and habitual activity (Brown, Ford et al. 2005). Women who were active (one hour or more of moderate intensity activity per week) at baseline were 30 to 40% less likely to have poor mental health and depression scores than those less active. Those in the lowest category at baseline who became more active were also at lower risk of poor mental health scores than those who remained inactive. This association was independent of pre-existing physical or psychological health status. People who have chronic health problems are less likely to be physically active and depression is more common in those with illness than in the healthy (Leon, Ashton et al. 2003).
Mental ill health preventionThere is limited trial evidence for physical activity in the primary prevention of mental health problems. A review of interventions to prevent depression in older people did not include any physical activity trials (Cole and Dendukuri 2004). Habitual physical activity has not been shown to prevent the onset of depression. However, there is growing evidence for the use of physical activity in the management of depression. This evidence will be discussed further in Chapter 9.
Top of page