There is a strong difference between casual use of drugs and addiction to them. However transitioning between one and the other is easier than some may think, many don't even realise they are becoming addicted to something until it's too late. Forcing them to continue using, possibly more often as time goes on, or to put up with the withdrawal symptoms of attempting to cut a drug out. Many seem to think there are ways to prevent drug addiction and some of them may work, but it is important to keep in mind that tolerances differ from person to person and not all methods of preventing addictions will work for everyone.
The key to not becoming addicted to substances seems to be closely linked to usage. Making sure use rates are low will aid in the body not becoming dependant on the drug that is being used. Using a substance infrequently, such as a couple times per year will likely help avoid addiction as the substance is not coming into contact with the body frequently enough, or for long enough periods of time for the body to crave it. This means it could simply act as a temporary boost to the person's system that the body recovers from afterwards, not giving it time to become reliant on it to produce certain interactions. Of course this infrequent use is still dangerous and can still do long lasting damage depending on what substance is being used.
However if use is more frequent, higher chances of addiction are still present. As the body comes into contact with substances much more and they spend a lot more time in the body, producing reactions and creating chemicals that the body starts to rely on. If frequent use is something that really cannot be stopped then taking long regular breaks from it may help in preventing addiction. This is because it gives the body time to detox and rid the substance from the system, if withdrawal symptoms appear it may be an indication to reduce use and increase the times the regular brakes go on for. Using a substance frequently and taking regular breaks may help with addiction to a substance, but it does not make its usage safe.
Both of these methods of preventing addiction to a substance may be able to aid in reducing the withdrawal symptoms and need for consistent use of a drug. But they do not reduce the risk involved in using them at all. Issues with purity, overdose and long term health effects are still just as present and should be kept in mind at all times when deciding whether or not to use a drug. Drug addiction isn't always the worst part about usage, it can be the side effects of even a single use.