I fully believe that if Orson didn't use this crap he would have probably lived longer, and would not have had the weight problem he did.
Both drugs, no matter what one he used, are Amphetamines. They are stimulants and can also be used as appetite surpressants. And as any chubby person knows, if you use any kind of drugs to lose weight, once you quit you gain the weight back three-fold. And god only knows what the hell kind of other drugs Orson used to maintain his weight. Manufactured drugs were in its infancy during the early 30's, so it was all experimental. So, the overall effects and damages that they had on his body through out his life time is only guesswork. And, I read some where on these boards that Orson, prior to his death, lost a lot of weight. I wonder if he used some kind of weight loss drugs? Using these, not matter what kind of drug, probably increased his risk of an early death.
So, my point being is that I absolutely believe his weight gain was the cause of these drugs, and others if he used any more through out his life. And I truly believe that he would have lived longer, because once you think about it, 70 is kind of young compared the life span of, let's say, Bob Hope. I'm sure Orson could have lived for another ten or so years. And who knows what he could have accomplished in those extra ten years?!