While multivariate analyses confirmed that randomization to collaborative care was associated with greater improvement in mood symptoms ( odds ratio -LSB- OR -RSB- = @ ; @ % - confidence interval -LSB- CI -RSB- = @-@ @ , p < @ ) and mental HRQoL ( OR = @ , CI = @-@ @ , p = @ ) , use of antidepressant medication had no differential impact on either measure ( p = @ and p = @ , respectively ) .