In a Flash :-
A drug is defined as any substance which causes a biological change in humans or animals.
Many drugs such as alcohol, tobacco and Caffeine are legal in the UK.
Drugs which alter a person’s perception of the world (how they see things), mood or consciousness are known as psychoactive drugs.
Drug abuse is classed as the use of any illegal drug or the misuse of a legal substance.
Addiction and drug dependency can occur when drugs are abused.
More Detail :-
What is Substance Abuse and Addiction?
The difference between substance abuse and addiction is very slight. Substance abuse means using an illegal substance or using a legal substance in the wrong way. Addiction begins as abuse, or using a substance like marijuana or cocaine.
You can abuse drugs or alcohol without having an addiction. For example, just because Laura smoked weed a few times doesn't mean that she has an addiction, but it does mean that she's abusing a drug — and that could lead to an addiction?
People can get addicted to all sorts of substances. When we think of addiction, we usually think of alcohol or illegal drugs. But people become addicted to medications, cigarettes, even glue!
And some substances are more addictive than others: Drugs like crack or heroin are so addictive that they might only be used once or twice before the user loses control.
Addiction means a person has no control over whether he or she uses a drug or drinks. Someone who's addicted to cocaine has grown so used to the drug that he or she has to have it. Addiction can be physical, psychological, or both.
Being physically addicted means a person's body actually becomes dependent on a particular substance (even smoking is physically addictive). It also means building tolerance to that substance, so that a person needs a larger dose than ever before to get the same effects.
Someone who is physically addicted and stops using a substance like drugs, alcohol, or cigarettes may experience withdrawal symptoms. Common symptoms of withdrawal are diarrhoea, shaking, and generally feeling awful.
Psychological addiction happens when the cravings for a drug are psychological or emotional. People who are psychologically addicted feel overcome by the desire to have a drug. They may lie or steal to get it.
A person crosses the line between abuse and addiction when he or she is no longer trying the drug to have fun or get high, but has come to depend on it. His or her whole life centres on the need for the drug. An addicted person — whether it's a physical or psychological addiction or both — no longer feels like there is a choice in taking a substance.
Signs of Addiction
The most obvious sign of an addiction is the need to have a particular drug or substance. However, many other signs can suggest a possible addiction, such as changes in mood or weight loss or gain. (These also are signs of other conditions too, though, such as depression or eating disorders.)
More Detail :-
Signs that you or someone you know may have a drug or alcohol addiction include:
• use of drugs or alcohol as a way to forget problems or to relax
• withdrawal or keeping secrets from family and friends
• loss of interest in activities that used to be important
• problems with schoolwork, such as slipping grades or absences
• changes in friendships, such as hanging out only with friends who use drugs
• spending a lot of time figuring out how to get drugs
• stealing or selling belongings to be able to afford drugs
• failed attempts to stop taking drugs or drinking
• anxiety, anger, or depression
• mood swings
• changes in sleeping habits
• feeling shaky or sick when trying to stop
• needing to take more of the substance to get the same effect
• changes in eating habits, including weight loss or gain
If you are worried that you or someone you know has a problem with drugs or alcohol tell someone you trust and get help.