I guess this is like the food addict who keeps junk food in the house after struggling to lose a lotta weight, or ex-alcoholic who has not drunk in years but still has booze in the house. Just one trigger makes the temptation to fall off the wagon easier.
I have personally failed many times to get off and stay off this junk. When I was much younger, I recall getting off xanax for almost a year. It was not easy but I did it. I think excessive workplace stress during this time in my life was the catalyst for having the panic and anxiety return with a vengeance. That in turn caused me to start up again, even knowing how addictive these drugs are and how painful the w/d process is. Go figure--