It means that you are already an addict for you to allow gambling to be a threat to your peace of mind. This is the main reason why one needs to gamble responsible and stay healthy to avoid being addicted to gambling. Assuming, there is nothing like addiction and only losses when gambling, nobody will see gamblers as irresponsible people because they are still in control of your senses. Addiction takes over all your thinking mentality.
Peach of mind is the after math of every action, if your peace is taken you should know that something ha e triggered it to go, such as unbearable loses and pressure to meet certain amount to recover, this can become a worrying point that affects your overall peace of mind and could because a dip threat as far as addition is concerned, so you are very correct that the mate who's is an addict already will definitely be the one to exhibit such tendency of emotional imbalance.
In this matter, we need to be aware with our losses and not tolerate it if we continue gambling. Playing gambling need responsibility because that is what we need to do if we want to avoid the lose become big. We don't have to wait for the losses become big and stop because the risk will be bigger. Our losses can trigger us to get deeper in gambling and become addicted to gambling. We really need to prevent that happen to us by always control our money and stop gambling just in time. Being addicted to gambling will make us lose control and we only want to gambling without think how good our condition.