While Valium overdose is not common when being used as prescribed, it can most certainly happen in cases of misuse and addiction.
When someone who is using LSD develops a tolerance to the drug but stops taking it for a short period of time, such as a week, the drug will once again become effective.
Magic mushroom use generally causes feelings of nausea before the desired mental effects appear.
PCP's effects can vary from person to person and dose to dose, mainly because of significant variations in amount and composition of active compounds.