you can find many research papers on motor and cognitive degradation with alcohol but do you really need to have proof of that? marijuana is tougher to find but

you can find many research papers on motor and cognitive degradation with alcohol but do you really need to have proof of that? marijuana is tougher to find but I have read it has same effects not sure where. lsd and ecstacy may have opposite effects and amphetamines are cognitive enhancers so depends on the type of drug we are discussing here.