Effexor is  a mixed antidepressant. It is not a simple SSRI. A call to
the company that makes the drug might yield unpublished information on
peak breastmilk levels & impact on breastfeeding babies etc.
        According to Dr. Fred Goodwin, who was the Administrator of the Drug
Abuse , Mental Health and Alcoholism Administration under Presidents
Reagan and Bush (i.e. the top psychiatrist in the US),  SSRIs are
selective in the sense that they bind to seretonin transporters. He
informs mothers and supports their choice to breastfeed. He. personally,
looked into prozac (fluoxetine) which is an SSRI antidepressant. It is
taken once per day. He suggests it be taken at the time the baby sleeps
longest and avoid breastfeeding when the drug peaks in the milk. For
fluoxetine that is 6 hours after ingestion. This might permit exclusive
breastfeeding in good sleepers  or just one ABM feed in others.
        Dr Goodwin suggests mothers can breastfeed for 3 hours after taking
fluoxetine then not for 6 hours, avoiding the peak. He points out that
it leads to non-depressed mothers who stay well and can bond
appropriately with their babies!