People sometimes take more than one drug at a time. Some people may take alcohol, minor tranquillizers (Valium, Temazepam, Serapax), marijuana or heroin to help them relax or sleep.

This can make you dependent on several drugs at once. For example, some people need speed every day to help them get going and then take tranquillisers at night to get to sleep. This can lead to dependence and many serious physical and psychological problems.

Anyone can develop a 'tolerance'. Tolerance means that you must take more and more of the drug to get the same effect as you used to when you first started using (with smaller amounts).

'Dependence' means using takes up a lot of your thoughts, emotions and activities and makes you feel that you can't do things unless you have your drugs. Dependence can lead to a variety of health, money, legal, and work and relationship problems. Not all people who use are dependent.