Illegal drugs are drugs which a person is not allowed to own or use.

A drug is any chemical that affects the human body or mind when taken in any way.

Drugs and the law 
Countries and places have different laws for different drugs. 

Some drugs are allowed only if you have permission (called a “prescription”) from a doctor. Other drugs are illegal, meaning a person is never allowed to have them. 

If the police find a person with drugs they are not allowed to have, the police may take the person to court. Court cases may result in fines (requiring a person to pay money), prison, or in some countries execution.

Why some drugs are illegal 
A government may want to stop some drugs because they are bad to the people that use them, or because making the drug illegal will make the government more money.

A psychoactive drug affects the brain. Most laws against drugs are against psychoactive drugs.

Why people use drugs 
Some people use drugs as medicine if they are sick to help make them feel better. 

Some people might use drugs recreationally (for fun), these are usually controlled drugs. 

Some people use drugs to make themselves more productive or to help themselves stay awake, in this case they would use a stimulant such as amphetamines or caffeine.

Some people also use drugs because they are addicted. (See “Health effects of drugs” below)

Drugs in some religions 
Some Christians use small doses of wine as part of their religious ceremonies.

Some members of the Native American Church use Peyote (a type of cactus that contains the drug mescaline).

Some Hindus use cannabis (containing THC and CBD) as part of their religious rites.

Health effects
Drugs can have many effects on a person's health. Some drugs cause many people to die every year. Tobacco and alcohol can cause death, other drugs do not cause death. Cannabis and psilocybin mushrooms (“magic mushrooms”) do not cause death. But all drugs affect a person's health. 

Someone that used drugs may get intoxicated. Intoxicated people may do dangerous things. They may not be able to safely drive or operate machinery.

Overdose occurs when someone uses too much of a drug. Overdosing is very dangerous. It can cause death. Some drugs are easy to overdose on (heroin, alcohol, and aspirin). Other drugs are difficult to overdose on (LSD, cannabis). Many drugs cause long-term (long-lasting) health effects. Smoking tobacco can cause cancer. Drinking alcohol damages the liver (cirrhosis).

Sick people may use drugs as medicine to feel better. Opiates (morphine, heroin and codeine) are analgesics (painkillers). Nitrous oxide and ketamine are used as anesthetics (to force someone to sleep) for surgical operation. Amphetamines are legally prescribed to treat attention disorders in some countries, such as the United States.

Combining drugs often causes negative effects. A person may die if they combine multiple drugs.

Addiction and dependence 
An addiction is the repeated use of a drug. An addict (person with an addiction) uses the drug again and again. Addicts will continue to use the drug, even if the drug hurts them. Addiction causes cravings for the drug. A craving is an intense need for the drug's effects. Drug tolerance occurs when a person's body adapts to a drug. The body becomes more resistant to the drug and craves the drug all the time. If a dependent person stops taking the drug, they may become very sick or die. Most times medical help is needed to stop addiction. 

Addiction and dependence can happen separately from each other. People can be addicted to things that are not drugs, like gambling or sex. 

Some psychoactive drugs are very addictive (causing addiction, like alcohol, heroin, tobacco, methamphetamine and cocaine) other drugs are less addictive (such as khat, cannabis and caffeine) or not addictive at all (such as LSD and Psilocybin mushrooms). 

People with anxiety disorder, attention-deficit hyperactivity disorder (ADHD), bipolar disorder, major depression, antisocial personality disorder (ASPD), borderline personality disorder (BPD), and schizophrenia have a higher chance of getting addicted.

Ways drugs are used
Different drugs are used in different ways. The same drug can be available in different forms, and each form is used a certain way.

For example, Crack cocaine (cocaine in solid form) is smoked or vaporized, but powder cocaine (cocaine that looks like salt) is snorted.

Some ways drugs can be taken: 
 Orally – The drug is placed in the mouth, then swallowed. Pills are used orally.
 Smoked – The drug is burned, then the smoke is inhaled. Pipes, bongs, cigars and cigarettes are used to smoke.
 Insufflated – The drug is a powder. The powder is snorted directly into the nose.
 Vaporized – The drug is heated until it turns into a vapor. The vapor is breathed in.
 Sublingually – The drug is placed under the tongue. The drug is absorbed through the vein under the tongue. Dissolving tablets are an example of sublingual drug use.
 Buccally – The drug is absorbed through the cheek. The drug is placed between the cheek and the gums.
 Intravenous⁣ (also called IV) – The drug is injected into the veins. Usually, it is injected through the arm. A needle and syringe is used for injection.
 Intramuscular (also called IM) – The drug is injected into a muscle. A needle and syringe are also used for injection.
 Rectally – The drug is placed in the anus and absorbed there. The anal drug is called a suppository.
 Transdermally – The drug is absorbed through the skin. Nicotine patches and fentanyl patches are used transdermally.

Orally is the slowest method of using a drug because it must be digested in the stomach first. Injecting a drug (IV or IM) is the fastest method of using a drug. IV and IM drugs are most likely to cause an overdose. It is important to use clean needles to inject. Injecting with used or dirty needles spreads deadly infections (such as Hepatitis C or HIV).

Smoking anything can cause cancer. Smoking can also lead to emphysema (a disease of the lungs). Snorting a drug can lead to ear, nose, and throat conditions. Eating a drug can cause oral (mouth related) problems, like tooth decay.

Types of psychoactive drugs and their effects 
There are many categories (types) of psychoactive drugs (drug that affects the brain). These categories have subcategories (categories inside categories). For example, benzodiazepines and opiates are both subcategories of depressants. Some drugs, such as ketamine have elements of two categories (hallucinogens and depressants). Every drug is different, so it is important to know the effects of each individual drug.

Hallucinogens
Hallucinogens change the way people see, hear, feel or think. The three main groups of hallucinogens are: psychedelics, dissociatives and deliriants. Each group has different effects. They may cause hallucinations. Hallucinations are a feeling, sound, or sight that does not exist. When someone hallucinates, they feel, hear, or see something that is not truly there.

Stimulants
Stimulants speed up the central nervous system. People using stimulants may feel happy and excited. Also, they have more energy, concentration, or motivation. Stimulants may cause difficulty sleeping.

Depressants (downers) 

Depressants slow down the central nervous system. People using depressants feel happy, sleepy, and relaxed. Depressants slow down bodily functions such as breathing and heart rate. They may also make speaking or moving difficult. The difficulty speaking is “slurred speech”.

Anti-psychotics 
Antipsychotics are used to balance one's moods or stop hallucinations. Many anti-psychotics are legal prescription drugs. A person can have them if they have a prescription from a doctor. Anti-depressants help mood disorders like depression. Some anti-depressants are also anti-psychotics.

References 

Illegal drugs