Misc Why does it take anti-depressants a while to work?

[wooger]

I really had no idea where to ask this so I thought I'd try here.. sorry if this is the wrong place....

but I was wondering... as the title says really... why do antidepressants take such a long time to kick in? I mean alot of psychoactive drugs have an affect immediately.. benzos for anxiety, opiates for pain etc.

so yes! does anybody know the reason behind this?

thanks in advance

 

[amapola]

Well wooger there are a lot of antidepressants out there but the gist of it is your brain tries to counter the effects of the drug to maintain it's current state and it takes a while to adapt

For example SSRI (selective serotonin reuptake inhibitors) stop serotonin (a neurotransmitter) from going into the presynaptic cell. Therefore there are higher levels to bind to the postysnyaptic receptor. The higher levels of serotonin also trigger autoreceptors, which then tell your brain to stop making so much serotonin because there is so much of it already. Over a period of weeks these autoreceptors become less sensitive to the higher levels of serotonin, stop inhibiting its creation, and the drugs starts working.

 

[Captain.Heroin]

This thread has some good explanations.

 

[ferinox]

As amapola posted, autoreceptor desensitization is part of the picture. SSRI's also change the serotonin receptors ratios.

5ht1a agonist increases BDNF production increasing neurogenesis.It takes about a month for the benefits of increased neurogenesis to manifest. Blocking neurogenesis in animal studies, blocked the antidepressant effect of SSRI's.

Many antidepresssants appear to work by neurogenesis. Electro convulsive therapy also increases neurogenesis.

 

[wooger]

very interesting! thank you for your replies :D