Note Dr Healy's choice of words -

second is that paroxetine and venlafaxine are relatively more potent
serotonin reuptake inhibitors and this theory leads to a switch to less potent
serotonin reuptake inhibitors such as citalopram or one of the older
antidepressants such as imipramine.

http://www.seroxatusergroup.org.uk/David%20Healy%20Withdrawal%20Protocol%202009.pdf