Compared with the control group , the intervention group exhibited a reduction in depressive symptoms ( adjusted mean difference , 95 % confidence intervals ( 95 % CI ) : -3.12 , -1.03 to -5.26 ; P = 0.004 ) at the 6-month follow-up but no significant decrease in PSS scores ( -2.07 , -4.96 to 0.82 ; P = 0.16 ) .