You might think the police will only arrest someone who's caught dealing drugs. But even using drugs for your own personal use could land you with a large fine or time in prison.

Drug classifications

All drugs are put into one of three categories according to how dangerous they are.

It’s worth remembering that different drugs can affect people in different ways. Just because a drug is not Class A, it can still be very dangerous.

Class A drugs, including heroin, cocaine, ecstasy and LSD, have the most harmful effects.

Class B drugs, including speed, cannabis, mephedrone and some amphetamines, are less dangerous than Class A drugs but can still be harmful if misused.

Class C drugs, including ketamine, GHB and some tranquilisers, are less dangerous to the user than Class A and Class B drugs but are still classed as illegal and can be harmful.

Possessing drugs

If you're caught with drugs in your bag or your pocket, you could be charged with possessing an illegal substance, even if it’s not yours. If you're under 17, the police can tell your parent or guardian.

If you are found in possession of drugs, the punishment you receive will depend on the type of drug the police have found and your personal history.

If you were found with a Class C drug and don’t have a criminal history, you’ll probably receive a formal warning or a police caution. If you're found with a Class A or B drug, or have a history of drug offences, you're likely to face a much tougher punishment.

The maximum sentence for possession of each class of drug are:

- up to seven years in prison or an unlimited fine (or both) for a Class A drug

- up to five years in prison or an unlimited fine (or both) for a Class B drug

- up to two years in prison or an unlimited fine (or both) for a Class C drug.

These sentences can be increased a lot more if you are found to be dealing in drugs or supplying them - even if it's just to friends or no money changes hands.

Possessing Cannabis

Cannabis is a Class B drug.

If you are caught carrying some, police will confiscate it and you could be arrested, even if it’s your first time. What the police do depends on the circumstances and how old you are.

Over 18s

If you are over 18 and caught in possession of cannabis, the police are likely to:

- give you a cannabis warning for a first offence of possession

- give you a Penalty Notice for Disorder (an on-the-spot fine of £80) for a second offence

- arrest you if it is the third time you have been caught with cannabis; this could lead to a conviction and a criminal record

Aged between ten and 17

If you're caught in possession of cannabis aged between ten and 17, the police will confiscate the drug and could arrest you. They could also refer you to a Youth Offending Team (YOT) and are likely to:

- give you a reprimand and tell your parents what has happened if it’s the first time you’ve been caught

- give you a final warning and refer you to a YOT if it's your second offence

- arrest you if it is the third time you’ve been caught with cannabis, which could lead to a conviction and criminal record.

Possessing mephedrone

Mephedrone, or meow meow as it is also known, used to be legal to buy in the UK over the internet.

Following the deaths of several teenagers who had been taking the drug, mephedrone (and related cathinone substances) has now been classified as a Class B drug and is illegal to sell, buy or possess. Importing mephedrone into the UK has also been banned.

Intent to supply and dealing

Punishments for supplying drugs are a lot tougher than those for possession. It’s also important to remember that supplying drugs doesn't just apply to dealers.

If the police think you intended to share drugs with your friends, this is still considered as supplying.

Police are more likely to charge you if they suspect you intended to supply drugs, but will take into account the amount of drugs you had and your criminal record.

The maximum sentences for intent to supply drugs are:

- up to life in prison or an unlimited fine (or both) for a Class A drug

- up to 14 years in prison or an unlimited fine (or both) for a Class B or Class C drug.