Even though not all topics discuss the same level of addiction, if the topic is moderated in one topic (not allowing other topics to exist) then cases of addiction at any level can be discussed there.
You are right, each topic is made to be discussed with different complaints of gambling addiction and different ways of handling it depending on the level of addiction experienced, so even though each topic is very relevant for discussing gambling addiction, we hear different stories from bad gambling experiences, so their gambling addiction must be stopped immediately by providing the right solution.
I agree with your opinion to make a special topic that will be moderated about all discussions of gambling addiction problems, but I also agree with @Ryu_Ar1's opinion because locking threads will drown the topic of gambling addiction problems so the important point if there are many addiction topics will remind every gambler to think about the risks worst if he is a compulsive gambler it will be difficult to cure from gambling addiction.