For the binary secondary outcomes (e.g. major depression diagnoses at 6 months), in the "worst case scenario" (i.e. one of the two proportions is equal to 50%), a sample size of 100 patients in each group will have 60% power to detect a difference of 15% between the two proportions at the 5% level of significance. The power will increase as the two proportions are assumed to be lower than 50%. Based on the pilot study, most of these proportions are likely to vary between 10% and 30%. For example in the pilot study, the proportion of major depression at 6 month was 23%, the power to detect the same difference of 15% will then be 66%. The proportion of heavy use of alcohol at 6 month is 13%, the power to detect the same difference of 15% will then be 77%.