This means that using cannabis becomes far more important than other activities in their life. The person craves the drug and will find it very difficult to stop using it. People can develop a mild tolerance to cannabis. This means they need to take more and more to get the same effect. It is unsafe to drive after using cannabis.
Cannabis reduces concentration and co-ordination, impairs judgement and causes drowsiness.
It is always dangerous to combine drugs. It is widely believed that using cannabis leads people on to other illegal drugs. However, there is no evidence to support this. Most users of cannabis do not use other illegal drugs. The effects of cannabis on the unborn child are not entirely known.