I somehow suspect that the reference to soldiers taking drugs to circumvent the PVR route is added simply for dramatic effect in the article, either that or the soldiers in question are really crap at the statistical analysis invloved to calculate how long it will take you to;
(a) Start taking drugs.
(b) Get caught taking drugs by the CDT.
(c) Get thrown out for all of the above.
Much easier to sign on the line and wait one would think...
Just to add to the good old perennial of Booze versus Drugs, you can be a confirmed alchoholic and well on your way to an unpleasant and untimely demise without breaking a single law, whereas it is much harder to be a drug user without breaking laws or exposing yourself to the culture of crime associated with the purchase and use of drugs.