Stims work over time. May be 15/30 minutes and only do to ignore the effects from pain and fatigue. Ignore means not that the cause of is healed out. In my understanding I would call that overpowered. I'm sure that everybody agree, that you can't heal broken legs in that way. But you can stop the pain of distortions and other injuries. Pain effects can higher the stresslevel, lower walking speed and worsen aiming. Over time pain abate on its own. If the stresslevel of a soldier is to high, he can be hit by bad effects. Side effects of stims based on the same elements we carry all day with us. Is the biosystem not balanced and overused men can hit by that. A high stresslevel or using a stim can make irritating perceptions. For example that can happen everytime if men are involved in a car-/planecrash or out for combat in the deep dark jungle but also if they are stressed in their normal job. Changed behavior result from that simple effects in the personal vision and came from the players them self. There is nothing to do.