I have horrid anxiety ( to the point where I can literally freeze up when put on-the-spot stressful situations ) and I use Kratom lightly to deal with it. I noticed I was using a bit more than I thought was reasonable and I decided to do a hard stop and check for side effects. Well, the side effect in my case was horrid restlessness and anxiousness. It lasted for about 5 days. There is no throwing up or headaches, but basically all the anxiety I was mitigating came rushing back times 3 and it's extremely unpleasant. When researching online I did not find anyone else with this experience. When you use Kratom consecutively it's easy to build a tolerance. At the time I was consuming about 2 tablespoons a day 7 days a week for about a month.
Kratom when used sparingly is a good tool, but don't abuse it.
Generally its doesn't "feel" addictive but don't assume that it is without side effects and use it lightly.
I use it about 3 times a week and I limit my dosage to one teaspoon a day. This seems to give me the benefits without the side effects. I don't feel addicted to it and have no desire to consume more than this.
Just a heads up :)