The effects and dangers of drugs are influenced by many things. Personal factors involving the person who is using the drugs can be just as important as the drugs being used.
The drug experience and the expectations of the user are important. Many young people experimenting with drugs for the first time will be unsure about what to do or what to expect. This ignorance and lack of experience can itself be dangerous.
The mental or psychological state of the drug user is very important. The mood people are in when they take drugs influences the effects and dangers of drug use. If they are anxious, depressed or unstable they are more likely to have disturbing experiences when using drugs. They can become more anxious and disorientated, possibly aggressive, 'freak out' and do crazy things or take too much etc. As a general rule someone who is happy and stable is more likely to use more carefully and not be so badly affected.