I've tried so many things suggested here and elsewhere, including niacinamide, breathing exercises (I mean really, how do people do those when they're in a full-blown panic attack?!?), sugar, salt, more calories, magnesium...L-theanine has definitely helped me. I take 200mg on an empty stomach, usually later in the day as it can make me groggy. If I really start panicking (at home) I will lay on the acupressure mat and watch a TV show or something; I don't know how it works but it does help to relax me. Ativan is a last resort that I take if I feel like my day will be ruined if I don't stop the attack ASAP. Honestly though, these are all a plaster as I have underlying health issues that contribute to (and possibly fully cause) the anxiety. Without figuring out the root cause there is only so much you can do. I agree with the others saying endotoxin can cause anxiety as I have noticed an increase in my own after eating irritating foods.Shrimp, thank you for sharing. Have you tried different things and these ones are those that work for you best? Did you see any improvements or would you say these are just plasters? Thank you!