This leads to the need for increased doses to maintain the same effect
Prescription drugs, such as tranquillisers and sleeping tablets, which may have been prescribed for very good reasons, can also cause mental and physical health problems if used for long periods of time. Street drugs, such as cannabis or ecstasy, are usually taken for recreational purposes. For some people, problems start as their bodies get used to repeated use of the drug. This leads to the need for increased doses to maintain the same effect