Is it likely than an (a theoretical) SSRI receptor "burnout" affect all SSRIs?

Question

Assuming that it is possible that a receptor for a particular SSRI becomes "burned-out" or non-receptive (for what ever reason); would it be considered likely that the same receptor would be non-receptive for a similar SSRI?

Answer 1

I don't think so.  if that anti-depressant isn't working.. i doubt it will work at all.

Answer 2

If I understand you correctly, the answer is no.  Sometimes it does happen that a patient is stable on a particular SSRI, and then for some reason that medication stops working.  In that situation another SSRI can be substituted and the patient usually responds again to the second medication.

Answer 3

It's important to understand that SSRI's do not work directly at the serotonin receptor, they are traditionally thought to work at a nearby molecule called the 'serotonin transporter'. The transporter is responsible for cleaning up the serotonin after it is squirted to the next nerve down the line. When you clog up this transporter, it lets the next cell down the line get a stronger signal, because it's not cleaned up so fast.

SSRI p**p-out or burn out, which is what you may have heard of is a strange phenomena that pops up in people taking these drugs for long periods of time (usually longer than a year, but there are exceptions). For whatever reason, a particular SSRI just stops functioning as well as it should at a given dose. The dose can be increased, or another SSRI can be used, even one almost chemically identical to the one that doesn't work properly anymore.

This is not directly due to the 'receptor' burning out, as you say, but it probably has to do more with how the body is responding to the drug (SSRI's work at places other than the receptors, and current theory says this is where they do most of their work). The body could be chewing the drug up faster, or the chemistry of the brain could have changed so that the drug isn't giving enough of a kick, changes in weight and diet could alter the distribution of the drug. Cocktailing medicine for psychiatric conditions has a lot of trial and error involved.