According to research by the BBC, it is estimated that two million people in the UK suffer from some kind of substance addiction. The reasons that people become addicted are numerous and complex, with many different people citing many different reasons. The effects of drug use can be split into physical, psychological and social effects on the user.
Physical effects of drug use vary depending on which kind of drugs are being taken. Stimulants will increase blood pressure and heart rate, whilst barbiturates will make the users act far more slowly. All illegal drug use produces some kind of physical effect, which can in extreme cases turn out to be fatal.
The most disturbing effects of drug addiction and use tend to be psychological. Most drugs affect the brain in some way, disrupting messages as they travel between the brain and various parts of the body. Anaesthetic drugs such as ketamine disrupt pain receptors and make the user less likely to feel the sensation if they injure themselves. Drugs such as cocaine make users experience highs which cause them to use again to chase the initial high.
If the physical and psychological effects of drug use have affected the life of the user in a negative way, their social life is also likely to be affected in a negative way. Friends and family may shun the user, whilst employers may not feel they are able to remain in their job.