Researchers following the progress of 1,200 people for five years have found strong links between unhealthy lifestyles and depression.
Researchers at the University of Tasmania’s Menzies Institute for Medical Research studied the impact of lifestyle on depression and the impact of depression on lifestyle. This is the first time the association has been looked at from both sides.
The lead author of the study, Dr Seana Gall, says that people with healthier lifestyles at the beginning of the study were significantly less likely (22%) to develop a first episode of depression over the five years, while there was a tendency for those with a history of depression to lose points in a lifestyle assessment over the five years (46% more likely than those without a history of depression at the beginning of the study).
Lifestyles were assessed through a score comprising body mass index, smoking, alcohol consumption, leisure time, physical activity and diet.
These associations occurred regardless of other predictive factors such as socio-economic position, parental and marital status, social support, major life events, cardiovascular disease history and self-rated physical health.
Participants were aged 26-36 years at the beginning of the study (2004-2006) and 31-41 years at follow-up (2009-2011).
Dr Gall says the study’s grouping of health behaviours (the overall lifestyle) rather than looking at individual risk factors was significant.
“This is the first study to consider the association between this number of health behaviours and risk of developing depression over time,” Dr Gall says.
“Studying individual risk factors and their relationship with depression ignores the fact that risk factors often cluster as unhealthy lifestyles.
“Our findings have implications for reducing the higher risk of cardiovascular disease that is seen in those with depression and also potentially reducing the risk of developing depression in young people” Dr Gall says.
“The study highlights the need for holistic management of young adults in terms of their mental and physical health, including health behaviours.”
Dr Gall says the results suggest that a healthier lifestyle may protect against the first onset of depression and therefore the findings are relevant for those managing the physical and mental health of younger adults.
The research has been published this month in the journal Psychological Medicine.