Donsky - I have no actual clinical experience with Cymbalta (duloxetine), and I've only read some articles about it (in addition the manufacturers literature). Therefore, the information I am giving is going to be tainted with author's bias' (be forwarned).

Cymbalta is a dual action antidepressant who's effects (and side effects) are similar to Effexor XR (venlafaxine) at dosages over 150mg/day (at lower dosages, Effexor XR is more similar to the SSRIs). Cymbalta is classed as an SNRI (like Effexor XR) which stands for serotonin-norepinephrine reuptake inhibitor, because it blocks the reuptake of both of these neurotransmitters, resulting in increased electrical transmission in norepinephrine pathways, as well as serotonergic pathways.

While neither lack of serotonin, nor lack of norepinephrine in the gaps between the respective nerve cells can cause depression, decreased levels of these neurotransmitters is often seen in those with depression. The addition of the norepinephrine reuptake blocking effect does seem to increase the effectiveness of Effexor XR over the SSRIs in some people with refractory depression, the same is only assumed for Cymbalta. I have heard rumors that Cymbalta is not as effective in treatment resistant depressions as Effexor XR, but I have no proof of this.

Remember, in anxiety disorders it can take 8 weeks to see an effect with the SSRIs and Effexor XR. Also, panic/anxiety attacks increase in this time period as well; until the body adjusts to the drug. Cymbalta probably has a similar time to onset and "start-up" side effect profile as these other drugs. The Klonopin (clonazepam) should help take the edge off of the increase in these start-of-treatment anxiety attacks, until your body adjusts.

My laptop battery is fading; I hope that this is of some help. - Cam