Response rate in the citalopram and placebo groups based on per-protocol ( intention-to-treat ) analysis was 55.8 % ( 40.6 % ) and 39.5 % ( 30.3 % ) at week 4 ( p = 0.097 [ 0.169 ] ) and 72.0 % ( 52.5 % ) and 53.4 % ( 41.0 % ) at week 12 ( p = 0.059 [ 0.148 ] ) , respectively .