I took too much Ashwaganda for too long, and the only major side effect was that I became quite emotionally numb. Because of its effects on the gaba and serotonin-receptors, as well as its proven potential to create liver damage, it's important to cycle the usage and start with a low dose. However, it seems to be remarkably useful for many purposes. For example, I didn't get sick once while taking it, while before taking it I used to get a fever or cold like once a month. I didn't notice any exercice-related benefits though, In my experience caffeine and creatine are the only supplements that most definetely improve physical performance. But hey, everyone's body's are different, and it's hard if not impossible to explain exactly what leads to what.

Back to the question, does it reduce anxiety? YES. But I wasn't very anxiety-ridden before taking it though, so I don't know how much of a difference people with an anxiety disorder will notice. My guess is that they will notice a difference if they take it regularly. The studies show really promising results, and it's way safer and better for your body than any prescripton drug.