Protective lifestyle behaviours and depression in middle-aged Irish men and women: a secondary analysis

To examine the association between protective lifestyle behaviours (PLB) and depression in middle-aged Irish adults.

Secondary analysis of a cross-sectional study. PLB (non-smoker, moderate alcohol, physical activity, adequate fruit and vegetable intake) were assessed using a general health and lifestyle questionnaire and a validated FFQ. Depression was assessed using the Center for Epidemiologic Studies Depression Scale. A score of 15-21 indicates mild/moderate depression and a score of 22 or more indicates a possibility of major depression. Binary logistic regression was used to examine the association between PLB and depression.

Livinghealth Clinic, Mitchelstown, North Cork, Republic of Ireland.

Men and women aged 50-69 years were selected at random from a list of patients registered at the clinic (n 2047, 67 % response rate).

Over 8 % of participants engaged in zero or one PLB, 24 % and 39 % had two and three PLB respectively, while 28 % had four PLB. Those who practised three/four PLB were significantly more likely to be female, have a higher level of education and were categorised as having no depressive symptoms. Engaging in zero or one PLB was significantly associated with an increased odds of depression compared with four PLB. Results remained significant after adjusting for several confounders, including age, gender, education and BMI (OR=2·2; 95 % CI 1·2, 4·0; P for trend=0·001).

While causal inference cannot be established in a cross-sectional study, the findings suggest that healthy behaviours may play a vital role in the promotion of positive mental health or, at a minimum, are associated with lower levels of depression.