Posted by Sad Panda on March 4, 2004, at 11:19:41
In reply to Re: Anyone suffer paradoxical depression with TCAs?, posted by King Vultan on March 4, 2004, at 8:17:25
> > I remember when I started Anafranil ages back, it caused a sever depression after 2/3 days on 25mg.
> >
> > Has anyone ever experienced this and, if so, does the depression pass, and the AD effect take over?
> >
> > Cheers,
> > Ace
>
>
> IMO, SSRIs would be more likely to cause a paradoxical depression than tricyclics in general. Why? The initial target of SSRIs is the presynaptic serotonin 1A receptor, which is inhibitory. Blocking serotonin reuptake causes these receptors to be pummelled with serotonin. If a person is so depressed that their serotonin neurons aren't really firing anyway, a person won't notice any immediate change in mood, but if a person's serotonin neurons are still firing at a moderate level, the stimulation of these inhibitory 1A receptors may cause the serotonin neuron to slow down its firing rate, triggering a worse depression.
>
> I have taken both SSRIs and tricyclics and looked into their psychopharmacology in some detail, and my opinion is that the tricyclics are less likely to cause a paradoxical depression, this because of their blockade of norepinephrine reuptake. That be said, Anafranil is the lone TCA that is also an SSRI, but it is much less selective than are typical SSRIs. The other tricyclics either blockade both serotonin and norepinephrine reuptake (amitriptyline, imipramine) or selectively inhibit norepinephrine reuptake (nortriptyline, desipramine, protriptyline).
>
> Todd
>Clomipramine is a potent NE reuptake inhibitor too. Clomipramine, Imipramine, Amitriptyline, Dothepin & Doxepin are very similar in their NE reuptake blocking ability.
Cheers,
Panda.
poster:Sad Panda
thread:319923
URL: http://www.dr-bob.org/babble/20040304/msgs/320126.html