The real issues about tapering off of these drugs is that NOBODY understands the multitude of ways they affect the body and make permanent changes to the cardiovascular system, brain, neuromuscular, endocrine, etc. Doctors, especially, do not understand or try to. If you are one who has bad post acute withdrawal (hits after off of the drug), reinstating the drug may not work. I can't emphasize that enough. It's not as simple as "I'll go off and go back on if I have to". Some people have no problems at all and others are permanently disabled by withdrawal.
Serotonin has numerous effects on the cardiovascular system, for example. It is stored in platelets, effects clotting, vasodilation, just to name a few. Since I tapered off of Pristiq over a YEAR in 2010-11, my BP and heart rate will not stabilize. They swing wildly within a minute or two. It's autonomic dysfunction, but no doctors understand it in this context or know how to control it. It's not unusual for my BP to be 60/30ish. Then go up to 160/110 within a short time. It's horrible. Same with heartrate. There are really no treatments for low BP (SSRIs are mentioned to increase BP), but when it swings both ways, it's hard to treat. A pacemaker has been suggested for heartrate. I'm aware of a few other people who've required pacemakers after withdrawal. I am mostly bedbound because this is so erratic and I pass out. It is posdibly neurogenic.
I had NO early warning signs or typical acute withdrawal symptoms during tapering. No zaps, nausea, etc. So, I marched on. I'm now on more drugs than before I tapered off of Pristiq. I've been to doctors across the USA, all with conflicting diagnoses. I have brain lesions, but no specific dx aside from autoimmune diseases that may be causing lesions. SS/NRIs do trigger autoimmune diseases, lupus, in particular. It does not go away with removal of the drug.
My best advice to people is don't start these drugs until every possible medical, nutritional, vitamin, mineral disorder is ruled out and serious therapy is used. I was put on Zoloft in '93 for mild fatigue and not depression or anxiety. I had immediate neuromuscular movement reactions, but no doctor made the connection until recently. I lost everything at age 39 — career, home…life as I knew it. Then, withdrawal made everything so much worse. I'm now 55 and have no life and am too sick to try. I have no family, friends don't know how to help, and they fall away after a few years of being sick.
Please, please be very cautious, go slowly, never CT, don't skip doses, etc. You may have no problems or you may end up like me or worse.