Are all drugs addictive?

Addiction definition. People can become psychologically dependent on any drug – or anything else for that matter. This means that the person using drugs feels they cannot cope or face the world unless they are under the influence of drugs. In contrast people can only become physically dependent on certain drugs. Physical dependency results from the repeated, heavy use of drugs like heroin, tranquillisers and alcohol.
Depends. If you are talking about narcotics than yes. They all are addictive more or less.