Physical activity and core depressive symptoms in the older Irish adult population.

Research indicates that the prevalence of depression is increasing and that by 2020 depression will become the second leading cause of disease worldwide, as measured by disability adjusted life years. Interventions which involve physical activity have shown that becoming active, even at a moderate level; can be effective in treating depression. In addition, physically active individuals are less likely to develop depressive symptoms than those who are not active, making physical activity an important strategy in the prevention of ill health.

The aim of this study was to investigate the associations between physicalactivity levels and core depressive symptoms in Irish adults aged 50 years or more. The study used data from the Survey of Lifestyle, Attitudes and Nutrition (SLÁN) 2007, a national survey of individuals living in the Republic of Ireland (n=4,255 adults aged 50 years or older) and The Northern Ireland Health and Social Wellbeing Survey (NIHSWS), 2005-2006, a survey of individuals living in Northern Ireland (n=1,904 adults aged 50 years or older).

Measures of depressed mood and anhedonia (two core depressive symptoms according to diagnostic criteria (DSM IV)) were derived using items from the surveys. Physical activity patterns were categorised using the International Physical Activity Questionnaire (IPAQ) Short Form (Craig et al. 2003). Demographic factors (age, gender and social class), smoking status and health service use were also considered.

Just over 5% (5.4%) of SLÁN 2007 participants and 11.1% of NIHSWS 2005-2006 participants had experienced both depressed mood and anhedonia in the recent past. In the overall sample this was 7.2% of participants. Overall 45% of participants reported being moderately physically active but 36.6% of participants reported activity at low levels (SLÁN 2007: 35.6%; NIHSWS 2005-2006: 38.8%). For the overall sample, depressive symptoms were negatively associated with being male, being older and high levels of physical activity. Depressive symptoms were significantly and positively associated with being separated/divorced or widowed, and social classes 3-6. Overall, people over 50 years who were engaged in moderate to high levels of physical activity had a 50-56% reduction in the odds of having elevated depressive symptoms.

Consistent with other research findings, this study suggests that physical activity levels are strongly associated with depressive symptoms. Increasing levels of physical activity among adults over 50 years has the potential to improve mental health.