Objective: To examine the effectiveness of a 12-month MHBC intervention in the prevention of onset depression in primary health care (PHC).
Methods: Twenty-two PHC centres took part in the cluster-randomized controlled trial. Patients were randomized to receive either usual care or an MHBC intervention. The endpoints were onset of major depression and reduction of depressive symptoms in participants without baseline depression at a 12-month follow-up.
Results: 2531 patients agreed and were eligible to participate. At baseline, around 43% were smokers, 82% were non-adherent to the Mediterranean diet and 55% did not perform enough physical activity. The intervention group exhibited a greater positive change in two or more behaviours (OR 1.75 [95%CI: 1.17 to 2.62]; p = 0.006); any behaviour (OR 1.58 [95%CI: 1.13 to 2.20]; p = 0.007); and adherence to the Mediterranean diet (OR 1.94 [95%CI: 1.29 to 2.94]; p = 0.002), while this increase was not statistically significant for smoking and physical activity. The intervention was not effective in preventing major depression (OR 1.17; [95% CI 0.53 to 2.59)]; p = 0.690) or reducing depressive symptoms (Mean difference: 0.30; [95% CI -0.77 to 1.36]; p = 0.726) during follow-up.
Conclusions: As compared to usual care, the MHBC intervention provided a non-significant reduction in the incidence of major depression