What is the worst drug? There is no doubt that all illegal drugs are not good for you and are potentially dangerous. This is due to NO control on what goes inside them. Drugs such as Heroin and Crystal meth can cause long term physical damage while other drugs can cause long term psychological damage and can trigger off pre-existing mental conditions such as schizophrenia. Which ever way you look at it, illegal drugs do much more harm than good and should be kept clear of. If you would like more information on illegal drugs, or just need to talk about a friend, a loved one or your own addiction, then call one of our team on: 0845 3881 543 or Mobiles call 07811 606 606 for more details. Our phones are manned 24 hours a day, 365 days a year, and we can help.